Document Puyallup_doc_18bd0ede48

FINAL Clarks Creek Sediment Reduction Action Plan Prepared for Puyallup Tribe of Indians Puyallup, Washington March 21, 2013 ---PAGE BREAK--- ---PAGE BREAK--- 701 Pike Street, Suite 1200 Seattle, Washington 98101 FINAL Clarks Creek Sediment Reduction Action Plan Prepared for Puyallup Tribe of Indians, Puyallup, Washington March 21, 2013 ---PAGE BREAK--- ---PAGE BREAK--- iii DRAFT for review purposes only. Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Table of Contents List of Figures v List of Tables v List of Abbreviations vi Executive Summary ES-1 Purpose and Objectives ES-1 Sediment Source Evaluation ES-1 1. Introduction 1-1 1.1 Background 1-1 1.2 Action Plan Purpose and Objectives 1-2 1.3 Project Approach 1-3 1.4 Document Organization 1-4 2. Sediment Source Evaluation 2-1 2.1 Field Investigations 2-1 2.1.1 Geomorphologic Assessment 2-1 2.1.2 Channel Gradient and Geometry 2-2 2.1.3 Bed Sediment Sampling 2-4 2.2 Quantifying Sediment Sources 2-6 2.2.1 In-Channel Source Estimates 2-7 2.2.2 Hydrologic Modeling 2-9 2.3 Prioritizing Sediment Sources 2-13 3. Evaluation of Potential Sediment Reduction Measures 3-1 3.1 Formulation of Alternatives 3-1 3.2 Evaluation of Alternatives 3-7 3.2.1 HSPF Modeling 3-7 3.2.2 Magnitude-Frequency Analysis 3-8 4. Action Plan 4-1 4.1 Proposed Projects 4-1 4.2 Implementation Strategy 4-2 4.3 Monitoring and Adaptive Management 4-3 5. Limitations 5-1 6. References 6-1 ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Table of Contents iv Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Appendix A: Geomorphic Assessment and Sediment Analysis A Appendix B: Channel Cross-Section Survey B Appendix C: Annotated Stream Profiles C Appendix D: Tetra Tech’s Watershed Modeling Report D Appendix E: Geomorphically Significant Flow Analysis E Appendix F: LID Design Concepts F ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Table of Contents v Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx List of Figures Figure ES-1. Sediment source evaluation process ES-2 Figure ES-2. Average annual sediment production in Clarks Creek basin ES-3 Figure ES-3. Average annual sediment production per unit area ES-3 Figure ES-4. Estimated reduction in average annual sediment load from implementation of selected projects (Alt 3) ES-4 Figure 1-1. Clarks Creek basin 1-2 Figure 2-1. Clarks Creek entering new channel in 1916 2-2 Figure 2-2. Channel cross-section survey locations 2-3 Figure 2-3. Stream profile plots based on LiDAR and cross-section 2-3 Figure 2-4. Sediment sampling locations 2-4 Figure 2-5. Grain size distribution of bottom sediment samples 2-5 Figure 2-6. Sediment source evaluation process 2-6 Figure 2-7. Eroded channel reaches in the Clarks Creek basin 2-7 Figure 2-8. Estimation of the volume of eroded material 2-8 Figure 2-9. Annual upland sediment production by subbasin based on HSPF modeling 2-10 Figure 2-10. Upland sediment source “hot spots” identified by HSPF model and GIS analyses 2-12 Figure 2-11. Average annual sediment production in Clarks Creek basin 2-13 Figure 2-12. Annual sediment production for the 16 largest identified 2-14 Figure 2-13. Annual sediment production per unit area for 16 largest sources 2-14 Figure 3-1. Process used to evaluate potential sediment reduction measures 3-2 Figure 3-2. Lower bound for geomorphically significant flows in Clarks Creek 3-4 Figure 3-3. Example of an effective work graph from the MFA spreadsheet tool 3-10 Figure 3-4. Estimated reduction in average annual sediment load from implementation of Alt 3 3-11 List of Tables Table ES-1. Project Results Summary ES-5 Table 2-1. Estimated Volume of Past Channel Erosion 2-8 Table 2-2. Upland Sediment Production Rates from HSPF Modeling 2-11 Table 3-1. Selected Projects for Alternatives Analysis 3-6 Table 4-1. Project Results Summary 4-2 ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Table of Contents vi Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx List of Abbreviations Action Plan Clarks Creek Sediment Reduction Action Plan (this document) BC Brown and Caldwell BOD biochemical oxygen demand cfs cubic feet per second CIP capital improvement project City City of Puyallup County Pierce County DEM digital elevation model DO dissolved oxygen Ecology Washington State Department of Ecology EPA U.S. Environmental Protection Agency ESA Endangered Species Act GIS Geographic Information system GPS Global Positioning System GSD grain size distribution HDS hydrodynamic separator HPA Hydraulic Project Approval HRU hydrologic response unit HSPF Hydrologic Simulation Program—Fortran LiDAR Light Detection and Ranging LF linear feet LID low impact development MFA magnitude-frequency analysis MS4 Permit Municipal Separate Storm Sewer System Permits (also known as Phase I and Phase II Municipal Stormwater Permit) NPDES National Pollutant Discharge Elimination System PSLC Puget Sound LiDAR Consortium QAPP Quality Assurance Project Plan SEPA State Environmental Policy Act SOW Scope of Work TKN total Kjeldahl nitrogen TMDL total maximum daily load TOC total organic carbon TP total phosphorus Tribe Puyallup Tribe of Indians TS total solids TSS total suspended solids WDFW Washington State Department of Fish and Wildlife WRIA Water Resource Inventory Area WSDOT Washington State Department of Transportation WSU Washington State University ---PAGE BREAK--- ES-1 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Executive Summary Purpose and Objectives The Puyallup Tribe of Indians (Tribe) regards Clarks Creek as a very important water resource. Clarks Creek provides habitat for five species of salmonids and is home to Tribal and state fish hatcheries. Recent studies suggest that excess sediment is a key water quality concern for Clarks Creek. To help address this concern, the U.S. Environmental Protection Agency (EPA) awarded the Tribe a grant to develop this Clarks Creek Sediment Reduction Action Plan (Action Plan). According to the Tribe’s grant application, full implementation of the measures identified by this project should result in the following outcomes at full build-out: • ~ 50% reduction in sediments and nutrients to Clarks Creek • ~30% reduction in fecal coliform bacteria concentrations • ~ 30% reduction in effective impervious surface area within the catchment • Support for all designated salmon uses in Clarks Creek (in the long term) • Significant decrease in elodea growth (and annual elodea control costs) • ~30% reduction in channel erosion (in the long term) • Attainment of water quality standards for dissolved oxygen (DO) in Clarks Creek This Action Plan describes a range of projects aimed at reducing sediment loads to Clarks Creek. Reducing sediment loads (and the pollutants commonly associated with sediment) should help improve habitat for Endangered Species Act (ESA)-listed salmonids, protect Tribal and state hatchery operations, meet dissolved oxygen (DO) and bacteria total maximum daily load (TMDL) objectives, and control elodea growth in the creek. The Tribe retained Brown and Caldwell (BC) (with subconsultants Inter-Fluve, AHBL, and WH Pacific) and Tetra Tech to help develop the Action Plan. The Action Plan was developed through a collaborative effort involving the Tribe, the City of Puyallup (City), Pierce County (County), Washington State Department of Transportation (WSDOT), Washington State Department of Ecology (Ecology), EPA, and Washington State University (WSU). Sediment Source Evaluation BC identified and ranked upland and in-channel sediment sources based on the following data: • geomorphological assessment of the Clarks Creek basin • sampling and analysis of channel bottom sediments • Hydrologic Simulation Program—Fortran (HSPF) modeling by Tetra Tech (under a separate contract) • Geographic Information System (GIS) analysis of the factors affecting sediment loads • field reconnaissance to ground-truth HSPF • sediment transport magnitude-frequency analysis (MFA) Figure ES-1 shows the steps in the source evaluation process. ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Executive Summary ES-2 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Figure ES-1. Sediment source evaluation process Sediment Sources The sediment source evaluation found that upland sources account for about 68 percent and in-channel sources account for about 32 percent of the average annual sediment load in the Clarks Creek basin (Figure ES-2). However, as shown in Figure ES-3, the in-channel sources generate considerably more sediment per unit area than do the upland sources. Moreover, the average annual channel erosion rate for recent years may be higher than the long-term average due to recent development in the upper watershed, Obtain upland sediment loading estimates from HSPF output. Spatially distribute loadings using GIS input data sources. Map Level 1 and Level 2 production rates as “hot spots.” Stream walk to identify degrading stream reaches. Estimate volume of sediment lost based on above dimensions. Assuming 1916 as starting point, calculate annual loss rates. Conduct field reconnaissance of upland sediment sources. Estimate degradation depths, and affected area. Upland Sources In-channel Sources Sediment source map and ranking. ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Executive Summary ES-3 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Figure ES-2. Average annual sediment production in Clarks Creek basin Note: Upland source areas shown in Figure 2-10. Figure ES-3. Average annual sediment production per unit area Note: Upland source areas shown in Figure 2-10. ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Executive Summary ES-4 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Sediment Reduction Projects BC worked with the Tribe, City, County, EPA, Ecology, WSU, and WSDOT to identify, evaluate, and select potential projects for reducing sediment loads from the key sources in the Clarks Creek watershed. BC used the HSPF model, developed by Tetra Tech, and MFA to estimate the sediment reduction benefits from each project. This analysis indicated that the selected projects should be able to achieve the Action Plan goal of 50 percent reduction in sediment loads (see Figure ES-4). Figure ES-4. Estimated reduction in average annual sediment load from implementation of selected projects (Alt 3) BC developed general planning-level concepts and cost estimates for the selected projects. Table ES-1 provides summary information for the selected projects. Project costs were compared based on a normalized benefit-cost index. The index was calculated by dividing the annual sediment load reduction for each project by the estimated cost for that project, and then dividing that by the ratio for all projects. An index value greater than 1 indicates that a project has a benefit-to-cost ratio that is higher than the average for all of the projects included in Alt 3. The benefit-cost index described in the previous paragraph is based on the identified sediment sources, which, in the case of in-channel sources, is limited to the erosional problem areas for each of the assessed streams. Projects that provide flow control can also help prevent future degradation of currently stable stream reaches. Table ES-1 also provides a qualitative rating of the flow control benefit for each project. 0 100 200 300 400 500 600 700 800 900 Natural Existing Buildout Alt3 Average Annual Sediment Production (tons/year) In-channel Upland 52% Reduction ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Executive Summary ES-5 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Table ES-1. Project Results Summary ID Project description Cost estimate Annual sediment load reduction (ton/yr) Normalized benefit-cost index (1.0 = average) Flow control benefit Pr01 Rody Creek channel stabilization $1,109,000 6.7 0.8 Low Pr02 Diru Creek bank stabilization $194,000 7.7 5.5 Low Pr03 Woodland Creek channel stabilization: lower $571,000 13.5 3.3 Low Pr04 Woodland Creek channel stabilization: upper $1,033,000 38.9 5.2 Low Pr05 Upper Clarks Creek channel stabilization $1,962,000 77.0 5.4 Low Pr06 Upper Clarks Tributary channel stabilization $1,146,000 56.4 6.8 Low Pr07 Silver Creek channel stabilization: lower $366,000 8.2 3.1 Low Pr08 Silver Creek channel stabilization: upper $769,000 34.8 6.2 Low Pr09 Rody Creek detention facility retrofit $443,000 4.4 1.4 High Pr10 Diru Creek detention facility $2,051,000 5.9 0.4 High Pr11 Woodland Creek detention facility $5,748,000 11.2 0.3 High Pr12 Clarks Creek detention facility $8,848,000 5.1 0.1 High Pr13 Silver Creek detention facility $6,640,000 8.3 0.2 High Pr14 Hatchery pond retrofit (sedimentation basin) $472,000 9.5 2.8 Low Pr15 15th Street stormwater diversion $1,285,300 54.9 5.9 High Pr16 7th Avenue stormwater diversion $11,731,000 31.1 0.4 High Pr17 72nd Street stormwater improvements $551,000 0.8 0.2 Low Pr18 North Pioneer stormwater treatment facility $187,000 2.3 1.7 Low Pr19 South Pioneer stormwater treatment facility $173,000 1.4 1.1 Low Pr20 16th Street SW stormwater treatment facility $157,000 0.8 0.7 Low Pr21 11th Street SW stormwater treatment facility $164,000 1.1 0.9 Low Pr22 Street edge/bioretention for secondary roadways $1,607,000 3.9 0.3 Moderate Pr23 Porous pavement for arterial roadways $6,663,000 7.7 0.2 Moderate Total $53,870,300 391.6 1.0 Implementation Strategy Implementation of the Action Plan will depend on the availability of funding from grants, City and County stormwater utility fees, and other sources. Opportunities to coordinate with infrastructure improvement projects or take advantage of land availability could accelerate the implementation of specific projects. Therefore, the Action Plan is structured to support a flexible implementation strategy rather than a fixed sequence. Proponents can select the projects that align with anticipated revenues and take advantage of opportunities grants, complementary projects, availability of land) as they arise. ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Executive Summary ES-6 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Full implementation of this Action Plan could take 20 years or more. Basin conditions are likely to change over time due to changes in land use/land cover, new regulations, and new infrastructure, as well as implementation of the Action Plan projects. Before implementing a given Action Plan project, the project proponent should assess the situation to confirm that the project is still necessary and revise it as necessary to align with current conditions. The Action Plan projects are designed to alter the dynamic processes that are contributing excess sediment loads to Clarks Creek. Monitoring should be conducted during Action Plan implementation to evaluate changes in channel conditions and confirm that the implemented projects are functioning as intended. The monitoring results should help determine whether the concepts for the remaining unbuilt projects should be modified to enhance their effectiveness and/or reduce costs. ---PAGE BREAK--- 1-1 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Section 1 Introduction This section presents a brief explanation of the background to this Action Plan, and describes the Action Plan purpose and objectives, project approach, and Action Plan document organization. 1.1 Background Clarks Creek is a tributary to the Puyallup River in Water Resource Inventory Area (WRIA) 10. The 3.6– mile-long creek drains an area of approximately 6,600 acres of urban and rural land within the city of Puyallup (City) and Pierce County (County) (see Figure 1-1). Maplewood Springs provide 30 to 40 cubic feet per second (cfs) of baseflow to the Creek, which also receives flow from four smaller creeks and several storm drainage systems before discharging into the Puyallup River about 6 miles upstream of the Commencement Bay estuary. The Puyallup Tribe (Tribe) regards Clarks Creek as an extremely important water resource. It is one of the few creeks in lower WRIA 10 that still supports Chinook, coho, and chum salmon as well as steelhead, bull, and cutthroat trout. The Chinook salmon and steelhead found in Clarks Creek have been listed as threatened under the Endangered Species Act (ESA). Moreover, the Puyallup Tribe operates a state-of- the-art salmon hatchery on the creek. The Washington State Department of Fish and Wildlife (WDFW) operates a trout hatchery upstream of the Tribe’s hatchery. The City and County also consider Clarks Creek to be a very important resource for aesthetic and recreational uses as well as aquatic habitat. Two City parks are located along the creek. Past monitoring found that Clarks Creek often exceeded the state water quality criteria for fecal coliform bacteria. The Washington State Department of Ecology (Ecology) established a total maximum daily load (TMDL) to reduce fecal coliform levels in Clarks Creek and its tributary Meeker Creek. Recent monitoring by the Tribe found dissolved oxygen (DO) concentrations that were below the state water quality standards for protection of salmonid habitat. The Tribe is working with the U.S. Environmental Protection Agency (EPA) and Ecology to develop a TMDL to improve DO in Clarks Creek. Dense growth of elodea nutalli (western waterweed) has plagued Clarks Creek for many years. The elodea appears to contribute to the DO problems in the creek and physically reduces habitat for salmonids. In addition, the elodea can become so dense that it causes flooding of riparian areas during baseflow conditions. Elodea debris has clogged the intake screens at the Tribe’s fish hatchery. The City and County have spent considerable time and effort on elodea control measures. Recent studies suggest that excess sediment is a key concern for Clarks Creek. It appears to reduce DO, promote elodea growth, and adversely affect physical habitat, and it may serve as a transport mechanism and reservoir for fecal coliform bacteria. Nutrients (particularly phosphorus and organic nitrogen) are often associated with sediments. Reducing the sediment loads would help protect and improve Clarks Creek’s uniquely valuable salmonid habitat and also reduce potential impacts on Puget Sound. Sediment load reductions could also help reduce fecal coliform levels in the creek. ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 1 1-2 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Figure 1-1. Clarks Creek basin 1.2 Action Plan Purpose and Objectives The Tribe received an EPA grant for a project titled “Reducing Effective Impervious Surfaces in a Small Urban Catchment Using Low Impact Development (LID) Practices.” As stated in the grant application, the project was intended to improve water quality in Clarks Creek by reducing sediment loads. The resultant water quality improvements should help improve habitat for ESA-listed salmonids, protect Tribal and state hatchery operations. Sediment reduction could also helpmeet the objectives of the existing bacteria TMDL as well as the DO TMDL that is currently being developed for Clarks Creek. Reduced sediment and nutrient loads could also help reduce elodea control costs for the City and County. The grant envisioned a collaborative effort involving the Tribe, the City, the County, and Washington State University (WSU) that would build on the County’s recently adopted Clear/Clarks Creek Basin Plan and complement the City’s ongoing LID, National Pollutant Discharge Elimination System (NPDES), and comprehensive planning programs. After the grant award, the Tribe conducted a procurement process and selected Brown and Caldwell (BC) and Tetra Tech to help conduct the project outlined in the grant application. BC and Tetra Tech had separate but complementary contracts with the Tribe. Tetra Tech developed the Hydrologic Simulation Program—Fortran (HSPF) model that was used to help identify sediment sources and evaluate potential reduction measures. The BC team included WH Pacific (surveying), Inter-Fluve (geomorphology and channel stabilization), and AHBL (LID concepts). ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 1 1-3 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx 1.3 Project Approach BC’s Scope of Work (SOW) for this project consisted of the tasks outlined below. Task 1: Project Initiation • Hold kickoff meeting with key stakeholders Tribe, EPA, Ecology, City, County, WSU) • Set up Web-based project collaboration portal Task 2: Compile Existing Data and Prepare QAPP for Field Investigations • Compile existing data relevant to upland and channel sediment sources, water quality, and existing and planned water quality and runoff control measures • Prepare Quality Assurance Project Plan (QAPP) to guide field data collection and hydraulic modeling Task 3: Perform Field Investigations • Conduct preliminary sediment source/geomorphology investigations data review and field reconnaissance) • Prepare map showing the apparent sediment point sources, relatively unstable channel reaches, and depositional reaches • Identify locations for sediment sampling and cross-section survey • Survey 36 locations on Clarks Creek and tributaries • Install monuments to facilitate future re-survey to assess trends and support adaptive management • Collect composite sediment samples from 20 channel locations and analyze the samples for total organic carbon (TOC), total Kjeldahl nitrogen (TKN), total phosphorus (TP, bacteria, and grain size distribution (GSD) • Prepare sediment data summary Task 4: Evaluate Channel Erosion and Sediment Mobility • Estimate historically eroded material based on comparison of current topography to the estimated former gradient and cross-sectional channel geometries • Extend existing HEC-RAS model to include the upper reaches of Clarks Creek • Perform uniform flow calculations to estimate flow depths and shear stresses for a range of flow rates for each of the tributary cross-section locations • Estimate thresholds for channel erosion using incipient motion analyses to determine relative sediment mobility and in-stream flow rates required to erode channel boundaries Task 5: Support HSPF Modeling and Prepare Sediment Source Summary • Meet with Tetra Tech staff to discuss the assumptions for HSPF modeling • Provide Tetra Tech with relevant Geographic Information System (GIS) files for HSPF modeling • Review and comment on the HSPF model calibration report prepared by Tetra Tech • Visit key sediment source areas identified based on the HSPF modeling, Task 3 geomorphology investigation, and Task 4 sediment mobility assessment • Prepare a table summarizing the upland and channel sediment sources and a map showing the key source areas ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 1 1-4 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Task 6: Evaluate Alternative Control Measures • Identify potential sediment reduction measures and work with stakeholders to develop up to three alternatives • Use the HSPF model developed by Tetra Tech to estimate the potential sediment load reductions associated with each alternative, assuming future land use conditions • Meet with the Tribe and key stakeholders to select the preferred alternative Task 7: Prepare Action Plan • Meet with the Tribe and key stakeholders to discuss implementation strategy • Develop concept drawings for the recommended LID measures and a map showing which LID measures are most appropriate for each portion of the basin • Develop a fact sheet (including a map, preliminary sizing, and planning-level cost estimate) for the capital improvement project (CIP) measures that appear implementable within the next 6 years given anticipated resources • Prepare draft Action Plan and revise if needed based on stakeholder comments Task 8: Project Management The Tribe issued a separate contract to Tetra Tech to provide modeling support for this project. Tetra Tech’s SOW included development of an HSPF model to simulate flow and water quality in the Clarks Creek basin. 1.4 Document Organization The SOW for this project called for a concise Action Plan that focuses on the recommended sediment reduction measures and facilitates preparation of grant applications for these measures. Therefore, the remainder of this document is organized as follows: • Section 2 provides a brief summary of the sediment source investigations. • Section 3 describes how sediment reduction measures were identified and evaluated. • Section 4 contains the Action Plan, which includes the following: − a fact sheet for each of the measures that comprise the selected alternative − the recommended sequence for implementing the measures − recommendations for post-implementation monitoring and adaptive management • Section 5 summarizes the project limitations. • Section 6 contains references. Appendices A through F contain detailed information on the activities and evaluations that were used to develop the Action Plan recommendations field reconnaissance, sediment sampling, surveying, modeling, and sediment transport calculations). ---PAGE BREAK--- 2-1 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Section 2 Sediment Source Evaluation This section summarizes the field investigations and analyses used to identify and prioritize sediment sources in the Clarks Creek basin. 2.1 Field Investigations Field investigations were conducted to assess the geomorphic conditions of streams within the basin, survey the existing channel geometry, and characterize the bed sediments found within the stream system. Subsection 2.1.1 summarizes the results from a geomorphic assessment of Clarks Creek and its major tributaries, Subsection 2.1.2 summarizes the results from a cross-section survey, and Subsection 2.1.3 summarizes the results of the sediment sampling and analysis. Additional information is provided in Appendix A. 2.1.1 Geomorphologic Assessment In June 2011, field reconnaissance was conducted along Clarks, Diru, Meeker, Rody, Silver, and Woodland creeks to assess the existing geomorphic conditions, identify potential sources of sediment, and make visual estimates regarding the volume of material lost along erosional stream reaches. Additional background research was performed to gain an understanding of the context of the current conditions with respect to historical anthropogenic influences. The following paragraphs summarize the key findings from this assessment; more detailed descriptions of the sediment source areas are included with the discussion of specific sediment sources (Section 2.2). Geologic Setting. The drop in elevation from the headwaters of the Clarks, Rody, Diru, Woodland, and Silver creek watersheds to the Puyallup River valley bottom is approximately 450 feet. Creeks within the study area drain relatively flat upland surface topography before running down a steep glacial terrace that forms the southern boundary of the Puyallup River Valley within the study area. The terrace is composed of glacial advance outwash sand and gravels, glacial till, and recessional outwash sand and gravels. When eroded, these provide a substantial sediment supply for segments of each tributary and Clarks Creek as it flows out to the Puyallup River. Erosion and Degradation. Clarks, Diru, Rody, Silver, and Woodland creeks all exhibit some signs of head cut erosion, stream bed lowering, and/or lateral slope instability. Although sufficient data are not available to determine precise causes, the observed erosional conditions likely resulted from a combination of the following historical events: • Propagation of a lowered bed elevation at the mouth of Clarks Creek, due to the channelization and straightening of the Puyallup River in 1916 (see Figure 2-1). This steepened the slope of the lower channel, thereby increasing the potential for channel erosion. • Increased runoff caused by land clearing and development within the Clarks Creek watershed • Recent large storms and floods, which may have triggered massive erosion in areas that had already become unstable. ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 2 2-2 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Figure 2-1. Clarks Creek entering new channel in 1916 Deposition and Aggradation. Sediment deposition has occurred in the low gradient reaches of Clarks, Rody, Woodland, and Silver creeks. Deposited materials in these reaches appear to be mostly sands with some silts; however, the lower reach of Clarks Creek near the Tribe’s hatchery contains larger amounts of silts and finer materials. Depositional zones containing sand and gravel were found in some places along upper reaches of Rody, Clarks, and Silver creeks, typically occurring for a short distance of major erosional areas. A masonry dam located near the Puyallup Trout Hatchery has also created a large depositional area. The reservoir behind the dam is nearly full of sediment and the upstream channel appears to be substantially aggraded. 2.1.2 Channel Gradient and Geometry Channel cross-sections were surveyed at 36 locations in the Clarks Creek basin (see Figure 2-2, Appendix The survey was conducted to provide channel geometry data needed for hydraulic modeling, geomorphic evaluations, and support development of control measures. In addition, two monuments were installed at each cross-section so that it can be re-surveyed in the future to assess trends and support adaptive management. Additional cross-section data were obtained from an existing hydraulic model developed for flood hazard mapping along lower Clarks Creek and lower Meeker Creek (NHC, 2005). Additional topographic data were obtained from the Puget Sound LiDAR Consortium (PSLC, 2011). PSLC data are developed from detailed Light Detection and Ranging (LiDAR) aerial surveys, and are provided in the form of digital elevation models (DEMs), which are data grids formatted for use with GIS. The DEM obtained for the Clarks Creek basin has a 6-foot grid resolution. LiDAR DEM data were used to create preliminary stream profiles by extracting elevations every 100 feet. The preliminary profiles were then adjusted to match the thalweg lowest point) elevations from the cross-section surveys described above. The resulting adjusted stream profiles were used to calculate the slope along any particular stream reach. Figure 2-3 shows the profiles for Clarks Creek and its tributaries. ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 2 2-3 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Figure 2-2. Channel cross-section survey locations Figure 2-3. Stream profile plots based on LiDAR and cross-section surveys 0 50 100 150 200 250 300 350 400 450 0 5000 10000 15000 20000 25000 30000 Elevation (feet) Stream Station (feet) Confluence with Puyallup River ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 2 2-4 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx 2.1.3 Bed Sediment Sampling Sediment samples were collected at 20 locations (see Figure 2-4). The locations were selected based on the geomorphologic assessment and previous water quality monitoring efforts. The samples were collected shortly after the City and County had completed their annual cutting of elodea in Clarks Creek. Figure 2-4. Sediment sampling locations The sediment samples were analyzed for TOC, total Kjeldahl nitrogen (TKN), nitrate and nitrite nitrogen, total phosphorus (TP), biochemical oxygen demand (BOD), fecal coliform bacteria, total solids (TS), and grain size distribution (GSD). Samples taken along lower Clarks Creek (Clarks-05 through Clarks-10) had relatively high quantities of silt and clay (Figure 2-5). Concentrations of TP, nitrogen, BOD, and TOC appeared to be higher in samples with higher percentages of fines. Fecal coliform bacteria concentrations were generally low and did not appear to increase with percent fines. ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 2 2-5 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Figure 2-5. Grain size distribution of bottom sediment samples Clarks-10 Clarks-09 Clarks-08 Clarks-07 Clarks-06 Clarks-05 Clarks-04 Clarks-03 Clarks-02 Clarks-01 Rody-01 Rody-02 Rody-03 Diru-01 Wood-01 West-01 East-01 Silver-01 Silver-02 Silver-03 Gravel Sand Silt Clay LEGEND Puyallup River Rody Creek Diru Creek Woodland Creek Silver Creek Meeker Creek Clarks Creek ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 2 2-6 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx 2.2 Quantifying Sediment Sources After the field investigations were completed, it was determined that sediment sources in the Clarks Creek basin can be divided into two general categories: • In-channel sources: Channel instability and degrading stream reaches are a substantial source of sediment to Clarks Creek and its tributaries. Incising and widening channels recruit new material from the bed and banks. The additional sediment is then mobilized and transported Although some of the coarser sediments may settle out a short distance finer sediments (fine sand, silt, and clay) are likely to be transported to the low gradient reaches along the valley floor, particularly along lower Clarks Creek, where flow velocities are low enough to allow much of the fine sediment to settle out. Appendix C contains annotated profiles for Clarks Creek and each of the major tributaries with degrading reaches. • Upland sources: Sediment is generated from both pervious and impervious surfaces. Sediment is generated from pervious land surfaces through soil erosion rainfall, runoff, and overland flow). Sediment from impervious surfaces is generated through the buildup and wash-off of accumulated sediments (from traffic, debris, wind-blown dust, etc.). Sediment production from pervious land surfaces is typically limited by the amount of runoff available to transport the material. Sediment production from impervious surfaces is typically limited by the sediment accumulation rate. Analyses were performed to estimate the amount of sediment being generated by each of the identified sources. In-channel sources were quantified using field-approximated volumes of eroded material, converted to an average annual loss rate assuming a 1916 start date. It is highly likely that erosion rates have increased due to more recent development in the upper watershed; therefore, the estimated annual channel erosion rates are likely to be conservative. A hydrologic model was used to estimate upland sediment production rates. Figure 2-6 illustrates the process used to quantify and rank specific sediment sources. Figure 2-6. Sediment source evaluation process Obtain upland sediment loading estimates from HSPF output. Spatially distribute loadings using GIS input data sources. Map Level 1 and Level 2 production rates as “hot spots.” Stream walk to identify degrading stream reaches. Estimate volume of sediment lost based on above dimensions. Assuming 1916 as starting point, calculate annual loss rates. Conduct field reconnaissance of upland sediment sources. Estimate degradation depths, and affected area. Upland Sources In-channel Sources Sediment source map and ranking. ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 2 2-7 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx 2.2.1 In-Channel Source Estimates Specific problem areas were identified during the field investigations, particularly areas exhibiting severe erosion and degradation. Figure 2-7 highlights specific problem areas found on Diru, Clarks, Rody, Silver, and Woodland creeks. Figure 2-7. Eroded channel reaches in the Clarks Creek basin Erosion and sediment transport rates are often highly variable and difficult to estimate, even with extensive field measurements and detailed modeling. For the Clarks Creek project, volumes of eroded material were estimated based on visual indicators of depth of incision, channel width, and bank height. Depth of incision was estimated from grade controls including trail and road crossings, roots, and logs spanning the channel. Nearby intact channel conditions were visually extrapolated to eroded sections to estimate depth of incision and channel width. Bank erosion was visually estimated by comparing exposed banks to nearby intact banks. An estimate of the eroded cross-section height and width (lateral migration), and whether the section was generally rectangular or triangular in shape were noted (see Figure 2-8). ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 2 2-8 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Figure 2-8. Estimation of the volume of eroded material of eroded segments were estimated using a handheld Global Positioning System (GPS) device, hip chain, pacing, or visual estimates. Total volumes of eroded material were estimated by multiplying the cross-sectional area by the length. Table 2-1 provides the resulting estimates of eroded material from each of the problem areas. Table 2-1. Estimated Volume of Past Channel Erosion Stream name Length of eroded reach (ft) Average loss per linear foot (yd3/ft) Total eroded material Total (yd3) Totala (tons) Annualb (tons/year) Clarks Creek of 23rd Ave. SE 1,300 3.5 4,600 6,100 64.2 Diru Creek upstream of 72nd St. E 700 0.8 530 710 7.4 Rody Creek of 80th St. E 500 0.9 460 610 6.4 Silver Creek upstream of 15th Ave. SE 500 1.0c 500 670 7.0 Silver Creek of 23rd Ave. SE 500 4.3 2,100 2,900 30.1 Upper Clarks Creek Tributary near 23rd Ave. SE 600 5.6 3,300 4,500 47.0 Woodland Creek of 80th St. E 900 1.0 c 900 1,200 12.7 Woodland Creek of 84th St. E 700 3.7 2,600 3,500 36.6 Total/average 5,700 2.6 14,990 20,190 211 a. Weight calculated from volume assuming a bulk density of 1.34 tons per cubic yard (approximately 100 pounds per cubic foot). b. Annual rate calculated assuming a 95-year time period (1916 to 2011), see discussion below. c. Assumed based on similar moderately incised reaches on Diru and Rody creeks. DEPTH WIDTH HEIGHT ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 2 2-9 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx The period over which the erosion occurred is unknown and the rate of erosions is difficult to gauge due to the varied stability and material composition between layers of glacial till and outwash. The assumed period of 95 years was based on the span between 1916 (when the Puyallup River was channelized) and 2011 (when the observations were made); however, it is highly likely that the observed erosion has occurred over a much more recent time frame. Therefore, the annual erosion rates provided in Table 2-1 are likely to be conservative. 2.2.2 Hydrologic Modeling Tetra Tech (April 2012) developed a watershed model of the Clarks Creek basin using the HSPF model, which is distributed by the EPA as part of the BASINS modeling platform. HSPF uses long-term meteorological data to simulate rainfall-runoff, interflow, and subsurface flow to streams. The model also simulates the production and transport of sediment and other pollutants as a function of land use and flow. A copy of Tetra Tech’s hydrologic modeling report is provided in Appendix D. HSPF Model Calibration and Validation. Tetra Tech performed calibration and validation of the hydrologic (stream flows) and sediment transport (sediment loadings) components of the model. Detailed discussions regarding performance targets, modeling results, and uncertainty are provided in Sections 5, 6, and 7 of the report in Appendix D. In general, the calibration and validation runs of the model found the simulated stream flows to fit the observed streams within the performance targets characterized as “good” to “very good1.” These simulations were based on several years of flow data, and thus, provide a reasonably high level of confidence in the long-term simulated stream flows. Calibration and validation of sediment loadings were based on limited observations of total suspended solids, and no small-scale monitoring has been conducted to estimate loads from individual land use areas. Nonetheless, the model provides a reasonable description of the processes contributing to sediment load and transport within the creek, based on multiple lines of evidence. Upland Sediment Loading. The HSPF model uses a variety of input parameters to represent pervious and impervious land surfaces, accounting for slope, soil properties, and land cover conditions. The model contains inputs for a wide variety of combinations, referred to as hydrologic response units (HRUs). For example, the model includes a specific HRU to represent a pervious land surface with well- drained soils hydrologic soil group moderate slope, and agricultural/pasture land cover. The model computes flow rates and sediment production2 rates for all of the HRUs contained in the model and then multiplies those rates by the respective areas covered by each HRU type. The HSPF model estimated that upland sources contribute about 460 tons of sediment per year to streams in the Clarks Creek basin (Tetra Tech, 2012). The computations within the model are aggregated into subbasins sub-drainage areas), allowing flows and sediment loading rates to be output at numerous discharges points. Figure 2-9 shows the subbasins delineated for the Clarks Creek basin along with the calculated annual upland sediment loading rates for each subbasin. 1 Performance targets and the associated ratings of “very good,” “good,” “fair,” or “poor” are described in detail in Section 5 of Appendix D. 2 The phrases “sediment production” and “sediment loading” are roughly synonymous in the context of this report. However, “sediment production” generally refers to the amount of sediment generated by a sediment source, and “sediment loading” generally refers to the amount of sediment discharged into the stream network at a particular point. ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 2 2-10 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Figure 2-9. Annual upland sediment production by subbasin based on HSPF modeling Values labeled for each subbasin represent sediment loading to streams in tons per year. ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 2 2-11 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Hot Spot Mapping. In addition to the subbasin results, sediment production rates for each HRU type (combination of soil, slope, and land cover) were obtained from the HSPF model. Upland sediment loading rates were found to be highest in highly developed areas with high levels of imperviousness. The HSPF modeling results suggest that impervious areas tend to produce higher sediment loads because more overland flow is available for transporting sediment to streams. However, much of the sediment probably originates from pervious areas directly adjacent to impervious areas (Tetra Tech 2012). Table 2-2 provides the HSPF-calculated sediment production rates by land use classification. Table 2-2. Upland Sediment Production Rates from HSPF Modeling Land use Sediment production (tons/ac/yr) Impervious percentage Wetland 0.000 0% Forest 0.011 0% Grass and pasture 0.030 0% Agricultural 0.033 0% Low-density development 0.038 5% Medium-density development 0.034 10% High-density development 0.168 78% Parks and institutional 0.071 15% Roadway 0.173 71% Average 0.076 27% Geospatial soil, slope, and land cover data were used to calculate the HRU areas within each subbasin. These same input data sets were then used to disaggregate and spatially map the upland sediment loading rates within each subbasin. In other words, sediment production rates were calculated for each HRU type and spatially distributed using the original GIS mapping data. The production rates were then divided into ranges Level 1 through Level 4, with Level 1 being the highest) and mapped (see Figure 2-10). Specific hot spot areas were delineated from the largest areas mapped as Level 1 or Level 2 sediment production zones. GIS data and aerial photography were then used to verify the reasonableness of the hot spots, and additional field reconnaissance was performed to “ground-truth” the results. Based on these checks, some upland source areas were marked as non-contributing for conditions such as: • Impervious surfaces that do not appear to be directly connected to the drainage network not considered to be effective impervious) • Areas draining to ponds or other stormwater infrastructure that could remove sediments • Areas that were observed to be mostly pervious with good vegetative cover. Note that within hot spot areas, focus should be placed on directly connected impervious areas and exposed soil immediately adjacent to those surfaces. ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 2 2-12 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Figure 2-10. Upland sediment source “hot spots” identified by HSPF model and GIS analyses Note: Non-contributing areas (white hatch) are not expected to contribute appreciable sediment (see page 2-11). ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 2 2-13 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx 2.3 Prioritizing Sediment Sources Total annual sediment production rates for in-channel and upland sources are summarized in Figure 2- 11. Upland sources account for about 68 percent and in-channel sources account for about 32 percent of the average annual sediment load in the Clarks Creek basin. As discussed previously, the average annual load estimates for in-channel sources assume that the observed sediment loss occurred at a constant rate between 1916 and 2012. It is likely that the current rate of channel erosion is higher than the long-term average due to recent urban development in the basin. Thus, in-channel sources may actually account for more than 32 percent of the current average annual sediment load. Figure 2-11. Average annual sediment production in Clarks Creek basin Note: Upland source areas shown in Figure 2-10. The annual sediment loading rates for the eight largest in-channel sources were graphed along with the annual sediment loading rates for the eight largest upland sediment “hot spots,” as shown in Figure 2- 12. The upland sources are much larger and more diffuse than the in-channel sources. For example, the upland source areas included in Figure 2-12 each cover between 28 and 123 acres. The in-channel sources generate much more sediment per unit area than do the upland sources (see Figure 2-13). ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 2 2-14 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Figure 2-12. Annual sediment production for the 16 largest identified sources Note: Upland source areas are shown in Figure 2-10. Figure 2-13. Annual sediment production per unit area for 16 largest sources Note: Upland source areas are shown in Figure 2-10. ---PAGE BREAK--- 3-1 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Section 3 Evaluation of Potential Sediment Reduction Measures This section describes how sediment control measures were identified and evaluated for inclusion in the Action Plan. Figure 3-1 provides an overview of the process. 3.1 Formulation of Alternatives BC reviewed the results of the sediment source evaluation to identify potential approaches for reducing sediment loads from the key sources in the Clarks Creek watershed. As noted in Section 2.3, steep, unstable channel reaches were found to be the most concentrated sediment sources in the watershed. The geomorphic assessment (Section 2.1) identified altered watershed hydrology as a likely cause for the observed channel erosion and bank failures. Loss of forest cover, creation of impervious surfaces, and construction of stormwater drainage systems have increased the duration of the “geomorphically significant flows” that cause bedload movement and accelerate channel and bank erosion. The Phase I and Phase II Municipal Stormwater Permits (also known as Municipal Separate Storm Sewer System [MS4] Permits) require onsite stormwater management (such as LID) and flow control measures for new development and redevelopment activities that replace or add hard surfaces. Minimum Requirements 5 and 7 are intended to reduce the duration of geomorphically significant flows that cause channel erosion and other adverse impacts. These requirements are summarized below. • Minimum Requirement 5, “On-site Stormwater Management,” contains a LID performance standard that applies to projects that result in greater than 2,000 square feet of new plus replaced hard surfaces. The requirement reads as follows: Stormwater discharges shall match developed discharge durations to pre-developed durations for the range of pre-developed discharge rates from 8% of the 2-year peak flow to 50% of the 2-year peak flow. Refer to the Standard Flow Control Requirement section in Minimum Requirement #7 for information about the assignment of the pre-developed condition. Project sites that must also meet minimum requirement #7 shall match flow durations between 8% of the 2-year flow through the full 50-year flow. • Minimum Requirement 7: “Flow Control,” contains a standard flow control requirement that applies to projects that result in greater than 5,000 square feet of new plus replaced hard surfaces. The requirement reads as follows: Stormwater discharges shall match developed discharge durations to pre-developed durations for the range of pre-developed discharge rates from 50% of the 2-year peak flow up to the full 50-year peak flow. The pre-developed condition to be matched shall be a forested land cover unless [specific conditions are met.] ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 3 3-2 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Figure 3-1. Process used to evaluate potential sediment reduction measures Sediment source map and ranking. 1. Identify potential mitigation measures for source reduction. 3. Screen out undesirable measures based on stakeholder input. 2. Perform a preliminary effectiveness/feasibility assessment. 4. Starting with existing plans, develop a list of potential projects. 5. Package projects into alternatives and analyze for reduction benefits. 6. All projects required to meet 50% reduction; select Alternative 3. 7. Develop conceptual designs and estimate project costs. 8. Prioritize projects into three tiers based on benefit-cost scores. In-channel Intervention Stakeholder Meeting Stakeholder Meeting Stakeholder Meeting Geomorphically significant flow analysis Magnitude Frequency Analysis (MFA) Hydrologic Modeling (HSPF) Project Totals: 2 2 5 5 1 8 Source estimates adjusted based on stabilized reaches. Stakeholder Meeting Sediment Basin Regional Detention Stormwater Treatment Distributed (LID) Stormwater Diversion “Hardscape” measures are ruled out by stakeholders Poorly-drained soils limit effectiveness for flow control. Potential challenges: size, land acquisition, permitting. City’s Comp Plan includes storm- water diversion at 15th Street, City suggests adding 7th Avenue diversion. City suggests stormwater treatment at 4 outfalls. County suggests treatment for 72nd Avenue . New on-line facilities difficult to permit, but existing pond at WDFW Fish Hatchery could be retrofitted to provide trapping and removal. Focus on public ROW for refitting. County’s Clear/Clarks Basin Plan contains recommendations for stabilization and detention. City suggests street edge and porous concrete. County rules out. Tribe requests evaluation of detention ponds upstream of degrading reaches. City targets10 miles of porous pavement on arterials and 10 miles of street- edge facilities on secondary roads. ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 3 3-3 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx BC calculated geomorphically significant flows for key channel locations in the Clarks Creek watershed to estimate the level of flow control that would be needed to reduce channel erosion. BC used the HSPF model, channel geometry data, and particle size data to calculate the geomorphically significant flows for 83 channel locations on the mainstem and tributaries. The results were compared to the flow control criteria contained in Minimum Requirements 5 and 7. Appendix E describes the methods and results. The following bullets summarize the key findings: • Calculated geomorphically significant flows vary widely within the Clarks Creek watershed (see Figure 3-2). • Calculated geomorphically significant flows for lower Clarks Creek correspond roughly to the flow thresholds of Minimum Requirement 7 in the MS4 Permit ( i.e., 50 percent of the 2-year forested discharge through the approximately the 50-year forested discharge). • Calculated geomorphically significant flows for upper Clarks Creek vary; the lower bound ranges from 5 percent of the 2-year forested discharge up to about 38 percent of the 2-year forested discharge). The upper bound tends to be two to three times larger than the 50-year forested discharge, likely due to the flow increases caused by urbanization. • Calculated geomorphically significant flows for the tributaries vary widely from reach to reach. The lower bound ranges from as little as 5 percent of the 2-year forested discharge to greater than 100 percent of the 2-year forested discharge. The upper bound can be as much as six times larger than the 50-year forested discharge, likely due to the flow increases caused by urbanization. • The lower flow bound was very low for the steepest, most incised stream reaches. This indicates that even small flows can cause bedload movement in these reaches. Controlling flows down to this level would be very difficult. Low-permeability soils cover most of the upper watershed, so infiltration potential is limited. Detention facilities would need to be very large in order to achieve the level of flow control needed to protect the steepest channel reaches. Given the wide range of geomorphically significant flows, it would be difficult to establish a “one size fits all” flow control standard tailored to the Clarks Creek watershed. The geomorphically significant flow analysis does suggest that the default standards described in Minimum Requirements 5 and 7 of the MS4 Permits would be a substantial improvement in the current flow regime and help to mitigate the potential for future channel instabilities ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 3 3-4 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Figure 3-2. Lower bound for geomorphically significant flows in Clarks Creek Achieving high levels of flow control will take many years and will not adequately address in-channel sources in the near term. Therefore, flow control regulations will likely need to be supplemented by capital projects. BC reviewed the City’s 2012 Comprehensive Drainage Plan and the County’s 2006 Clear-Clarks Creek Basin Plan to identify recommended projects that could help address the key sediment sources. The project team compiled an initial list of measures that could help address the key sediment sources in the watershed: • rain gardens and similar LID measures to remove upland sediment and reduce erosive flows and channel erosion • pervious pavement to reduce erosive flows and transport of sediment % of 2-year Forested Discharge ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 3 3-5 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx • detention ponds to reduce erosive flows and channel erosion, and trap sediment as well • sediment traps to reduce the sediment transport • stormwater treatment devices to remove sediment from runoff • high-flow bypass pipes to convey high stream flows past unstable channel reaches • stormwater diversion pipes to divert runoff and sediment away from Clarks Creeks and its tributaries • in-channel measures to reduce erosion of the bed and banks in steep, unstable reaches The team met with the Tribe, City, County, WSU, Ecology, and EPA on July 31, 2012, to discuss the potential measures and formulate alternatives for evaluation. The team also had a number of follow-up discussions with City and County staff. The following bullets summarize the key points of these discussions: • LID measures are likely to be effective for sediment removal but not very effective for flow control due to low-permeability soils in much of the watershed. Design concepts for onsite LID measures have been included in Appendix F. • The City would like to retrofit its arterials with pervious pavement in order to reduce the need for costly stormwater detention and treatment facilities. The retrofitting would be done when the roads are due for repaving. For secondary roads that require only patching or replacement of the wear layer (rather than repaving), the City would like to install bioinfiltration facilities in the rights-of-way. The City plans to continue its incentive program to encourage voluntary LID retrofitting on private land, but cannot reliably predict how much retrofitting will occur as a result. • The County does not plan to retrofit its roads in the watershed with pervious pavement or bioinfiltration facilities. • The County basin plan recommends using the existing pond near the WDFW hatchery as a sediment trap. The City noted that this pond is owned by WDFW. • The County’s basin plan also includes recommendations for detention ponds and channel stabilization measures that could help address key sediment sources. • Review of existing GIS data identified several additional areas where regional detention ponds might be feasible. Although additional data are needed to fully assess the feasibility of constructing regional detention ponds, stakeholders requested that detention projects be included on Diru, Woodland, Clarks, and Silver creeks. Regional ponds could reduce sediment loads by reducing the geomorphically significant flows that cause channel erosion and by trapping sediment from upstream areas. Potential ancillary benefits include removal of other pollutants and reduced flooding. The County noted that regional facilities are generally easier to maintain than small distributed facilities. Possible challenges for regional ponds include land acquisition, site suitability, hydraulic constraints, and environmental permitting. • The City and County were recently awarded grants for stormwater treatment projects in the Clarks Creek watershed. • The City’s Comprehensive Drainage Plan recommends a project to divert stormwater from the downtown area away from Clarks Creek and into the Puyallup River. Tribal staff expressed concern about discharging untreated runoff to the river. City staff noted that runoff from the diversion area would be treated in a Vortechs 9000 hydrodynamic device prior to discharge into the Puyallup River about 1.4 miles upstream of the confluence with Clarks Creek. The City installed the treatment device during the first phase of the diversion project. It is sized to treat runoff from the entire drainage basin after the diversion project is completed. ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 3 3-6 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx • In-channel measures will be needed to reduce channel erosion because of the limited opportunities for flow control upstream of the eroding reaches, at least in the near term. Over the long term, the flow regime should improve due to flow control requirements for new development and redevelopment, LID retrofits, and regional detention facilities. • Stakeholders would prefer to avoid “hard” channel stabilization measures, such as shotcrete and concrete drop structures. • Stakeholders also expressed disinclination toward flow bypass projects due to potential permitting difficulties and concerns for long-term maintenance. • The City and County are already sweeping streets throughout the basin on a regular basis. BC formulated three alternatives based on the July 31, 2012, meeting and follow-up discussions with the City, County, and other stakeholders. Table 3-1 summarizes the measures in each alternative. Table 3-1. Selected Projects for Alternatives Analysis Project type Brief description Location Jurisdiction Target source Alt 1 Alt 2 Alt 3 In-channel intervention Rody Creek channel stabilization of 80th Street E County In-channel    Diru Creek bank stabilization Upstream of 72nd Street E County In-channel    Woodland Creek channel stabilization: lower of 80th Street E County In-channel    Woodland Creek channel stabilization: upper of 84th Street E County In-channel    Upper Clarks Creek channel stabilization of 23rd Street SE City In-channel    Upper Clarks Tributary channel stabilization of 23rd Street SE City In-channel    Silver Creek channel stabilization: lower of 15th Street SE City In-channel    Silver Creek channel stabilization: upper of 23rd Street SE City In-channel    Regional detention Rody Creek detention facility retrofit Upstream of 90th Street E County Upland/in- channel   Diru Creek detention facility of 84th Street E County Upland/in- channel  Woodland Creek detention facility Near 90th Street E County Upland/in- channel   Clarks Creek detention facility Upstream of 23rd Street SE City Upland/in- channel  Silver Creek detention facility Upstream of 23rd Street SE City Upland/in- channel  Sediment trap Hatchery pond retrofit (sedimentation basin) Clarks Cr. near WDFW hatchery WDFW Upland/in- channel   Stormwater diversion 15th Street stormwater diversion Pioneer Avenue storm drain City Upland   7th Avenue stormwater diversion Diverted at 16th Street City Upland  ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 3 3-7 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Table 3-1. Selected Projects for Alternatives Analysis Project type Brief description Location Jurisdiction Target source Alt 1 Alt 2 Alt 3 Stormwater treatment 72nd Street stormwater improvements 72nd Street draining to Rody County Upland  North Pioneer stormwater treatment facility Clarks Creek stormwater outfall City Upland   South Pioneer stormwater treatment facility Clarks Creek stormwater outfall City Upland   16th Street SW stormwater treatment facility Meeker Creek stormwater outfall City Upland   11th Street SW stormwater treatment facility Meeker Creek stormwater outfall City Upland   Distributed (LID) Street edge/bioretention for secondary roadways Secondary roadways in city City Upland/in- channel  Porous pavement for arterial roadways Arterial roadways in city City Upland/in- channel  3.2 Evaluation of Alternatives Sediment reductions were evaluated using a combination of HSPF hydrologic simulations and magnitude-frequency analysis (MFA). The HSPF model developed by Tetra Tech (April 2012) was used to estimate upland source reductions and simulate changes in stream flow durations and frequency resulting from flow control measures. MFA computations were used to evaluate in-channel erosion potential under various combinations of flow regime, sediment composition, and hydraulic conditions. The most comprehensive alternative (Alt 3) was evaluated first to determine whether it would meet the overall project goal (50 percent reduction in average annual sediment loads). The initial evaluation was performed assuming full implementation of all 23 of the individual measures that comprise Alt 3. To evaluate the effect of each individual measure, the modeling was repeated assuming implementation of all measures except the measure in question. The results were then compared to the full implementation scenario in order to show the sediment reductions associated with a given measure. 3.2.1 HSPF Modeling Tetra Tech modified the existing conditions model to develop two additional scenarios: natural conditions fully forested) and future/buildout conditions (see Appendix The buildout scenario assumes that all parcels have been converted to their zoned land use except where protected from development (Tetra Tech, 2012). This change results in a higher level of total imperviousness. However, the buildout scenario also mitigates for this increased imperviousness based on current stormwater requirements for new development/redevelopment. In other words, impervious surfaces from redeveloped areas were routed through a hypothetical stormwater facility to adjust for current flow control requirements. Additional details are provided in Appendix D. The buildout scenario served as the baseline for evaluating future sediment reductions. The buildout conditions model was modified to represent the proposed Alt 3 scenario by adjusting for each of the 23 projects listed in Table 3-1. Details regarding the conceptual designs and sizing assumptions for each project are provided in the project fact sheets in Section 4. Upland Source Reductions. Upland sediment loadings to the stream network were calculated for each scenario. The difference between the total upland sediment loadings for Alt 3 and buildout equates to ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 3 3-8 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx the total reduction combined reduction resulting from implementation of all 23 projects. In total, Alt 3 resulted in about a 30 percent reduction in upland sediment sources. Additional HSPF simulations were run to estimate the individual reduction benefits for each of the proposed projects. These additional scenarios were modified versions of Alt 3, where the project being evaluated was removed from the model. In other words, the modified condition represents a scenario with only 22 of the 23 projects. The increase in upland sediment loading caused by removal of any particular project corresponds with the sediment reduction benefit that was being contributed by that project. The analysis must be done in this way to account for the overlapping benefits some projects have when they target the same sediment source. Flow Control. The HSPF model was also used to generate long-term stream flow hydrographs to evaluate changes in stream flow frequency and duration, and the resultant effects on erosion potential within the stream channels. Output hydrographs were processed into flow duration curves and flow frequency histograms distributions of flow within specified bins). These data were used as input for subsequent MFA evaluations. 3.2.2 Magnitude-Frequency Analysis MFA was performed to examine geomorphically significant flows (see Section 3.1 and Appendix E) and to evaluate measures for mitigating erosion potential in identified in-channel source reaches. Although the HSPF model developed by Tetra Tech contains sediment transport algorithms that can perform a similar function, MFA was used because it could be applied to specific problem locations and provides a more flexible framework for analyzing erosion potential. Effective Work. MFA is based on the concept of “effective work.” Wolman and Miller (1960) described how the geomorphic evolution of landscapes is strongly influenced by the amount of “work” done by the forces acting on the system. In streams, flowing water exerts shear stress on the bed and bank materials, and when sufficient force is applied, sediment is displaced and transported. The movement of sediment by water can be represented by a power function relating sediment transport to effective shear stress as follows: 𝑞= 𝑘(𝜏−𝜏𝑐)𝑛 where: q = the rate of sediment transport, k = a constant related to the characteristics of the transported material, τ = the shear stress per unit area, τc = the critical or threshold shear stress required to move the material, and n = an exponent (Leopold et al. 1964) The magnitude of the shear stress depends on the hydraulic characteristics of the stream channel (slope, geometry, roughness). The critical shear stress parameter (τc) represents the threshold below which no movement will occur, and is dependent upon the composition of the bed and bank sediments. Wolman and Miller (1960) also explained that the relative amount of work done depends not only on the magnitude of the force applied, but also on the frequency of occurrence. Therefore, the amount of work done in a stream depends not only on hydraulic and sediment characteristics, but also on the frequency and duration of stream flows. The product of the frequency of the occurrences and the magnitude of the influencing force is referred to as the “effective work.” ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 3 3-9 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Effective Work Index. In physics, work is defined as the integral of force over a distance of displacement. In the case of stream systems, work can be calculated based on stream power, or the product of flow velocity and shear stress. Total effective work was calculated using an effective work index defined as follows: 𝑊= 𝐶෍(𝜏𝑖−𝜏𝑐)𝑏∙𝑉𝑖 𝑛 𝑖=1 ∙Δ𝑡 where: W = the index of total work done (units of foot-pounds per square foot), C = a constant to dimensional or dimensionless units of work, n = the number of increments in the flow histogram, t = the applied hydraulic shear stress (pounds per square foot), tc = the critical shear stress that initiates bed movement (pounds per square foot), e = an exponent that captures the exponential rise in stream power with flow, V = the mid-channel flow velocity (feet per second), ∆t = the duration of flow for each time increment (seconds) The exponent, b, captures the exponential rise in stream power with increasing flow rates. For this analysis, b was assumed to be equal to 1.5, which is consistent with standard bedload transport functions such as the equation developed by Meyer-Peter and Muller (1948). MFA Tool. BC developed a spreadsheet tool to perform MFA calculations. This tool combines the flow frequency results from HSPF with hydraulic parameters and bed sediment sampling data to calculate effective work curves and estimate the effective work index under various scenarios (Figure 3-3). ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 3 3-10 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Figure 3-3. Example of an effective work graph from the MFA spreadsheet tool The sediment transport capacity curve (red) represents the rate of sediment movement magnitude of work) applied, while the flow frequency curve (blue) represents the frequency of the applied force. The product of those two curves results in the sediment loading effective work) curve (green). The total area under that curve represents the effective work index. The HSPF and MFA results indicated that the most comprehensive alternative (Alt 3) would achieve just over the Action Plan goal of 50 percent reduction in future sediment loads (see Figure 3-4). Therefore, no additional analyses were conducted on the less comprehensive alternatives (Alt 1 and Alt whose measures were included in Alt 3. Based on stakeholder input, Alt 3 was selected for conceptual design and cost estimates (see Section 0.00 0.20 0.40 0.60 0.80 1.00 1.20 0.0% 0.5% 1.0% 1.5% 2.0% 2.5% 0.00 0.01 0.10 1.00 10.00 100.00 Sediment Transport Rate (ft3/s/ft) Normalized Flow and Sediment Curves Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 3 3-11 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Figure 3-4. Estimated reduction in average annual sediment load from implementation of Alt 3 0 100 200 300 400 500 600 700 800 900 Natural Existing Buildout Alt3 Average Annual Sediment Production (tons/year) In-channel Upland 52% Reduction ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 3 3-12 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx ---PAGE BREAK--- 4-1 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Section 4 Action Plan Section 4.1 describes the selected projects for the Clarks Creek Sediment Reduction Action Plan. Section 4.2 discusses the strategy for implementing these projects. Section 4.3 prescribes long-term monitoring of channel conditions to evaluate progress and adjust the Action Plan as needed. 4.1 Proposed Projects Table 4-1 lists the projects comprising Alt 3, and provides summary information regarding project benefits and costs. A normalized benefit-cost index was calculated by dividing the annual sediment load reduction for each project by the estimated cost for that project, and then dividing that by the ratio for all projects. An index value greater than 1 indicates that a project has a benefit-to-cost ratio that is higher than the average for all of the projects included in Alt 3. Conversely, an index value less than 1 indicates that a project has a lower benefit-to-cost ratio that is lower than the average. As discussed above, due to recent development in the upper watershed, current channel erosion rates are probably higher than the long-term (1916-2011) average. Therefore, the estimated annual sediment reductions for channel stabilization projects could be conservatively low. Table 4-1 also provides a qualitative rating of the flow control benefit for each project. The benefit-cost index described in the previous paragraph is based on the identified sediment sources, which in the case of in-channel sources, is limited to the erosional problem areas for each of the assessed streams. However, projects that provide flow control can also help prevent future degradation of currently stable stream reaches. Eight projects (Pr01, Pr02, Pr03, Pr04, Pr09, Pr10, Pr11, and Pr17) are located in unincorporated Pierce County. The total estimated sediment load reduction from these projects is about 89 tons/year. Pierce County is now designing Pr09 and Pr17. The fact sheets for these projects should be updated to align with the County’s most recent design concepts and costs estimates. ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 4 4-2 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Table 4-1. Project Results Summary ID Project description Cost estimate Annual sediment load reduction (tons/yr.) Normalized benefit-cost index (1.0 = average) Flow control benefit Pr01 Rody Creek channel stabilization $1,109,000 6.7 0.8 Low Pr02 Diru Creek bank stabilization $194,000 7.7 5.5 Low Pr03 Woodland Creek channel stabilization: lower $571,000 13.5 3.3 Low Pr04 Woodland Creek channel stabilization: upper $1,033,000 38.9 5.2 Low Pr05 Upper Clarks Creek channel stabilization $1,962,000 77.0 5.4 Low Pr06 Upper Clarks Tributary channel stabilization $1,146,000 56.4 6.8 Low Pr07 Silver Creek channel stabilization: lower $366,000 8.2 3.1 Low Pr08 Silver Creek channel stabilization: upper $769,000 34.8 6.2 Low Pr09 Rody Creek detention facility retrofit $443,000 4.4 1.4 High Pr10 Diru Creek detention facility $2,051,000 5.9 0.4 High Pr11 Woodland Creek detention facility $5,748,000 11.2 0.3 High Pr12 Clarks Creek detention facility $8,848,000 5.1 0.1 High Pr13 Silver Creek detention facility $6,640,000 8.3 0.2 High Pr14 Hatchery pond retrofit (sedimentation basin) $472,000 9.5 2.8 Low Pr15 15th Street stormwater diversion $1,285,300 54.9 5.9 High Pr16 7th Avenue stormwater diversion $11,731,000 31.1 0.4 High Pr17 72nd Street stormwater improvements $551,000 0.8 0.2 Low Pr18 North Pioneer stormwater treatment facility $187,000 2.3 1.7 Low Pr19 South Pioneer stormwater treatment facility $173,000 1.4 1.1 Low Pr20 16th Street SW stormwater treatment facility $157,000 0.8 0.7 Low Pr21 11th Street SW stormwater treatment facility $164,000 1.1 0.9 Low Pr22 Street edge/bioretention for secondary roadways $1,607,000 3.9 0.3 Moderate Pr23 Porous pavement for arterial roadways $6,663,000 7.7 0.2 Moderate Total $53,870,300 391.6 1.0 4.2 Implementation Strategy Implementation of the Action Plan is voluntary and will depend on the availability of funding from grants, City and County stormwater utility fees, and other sources. Opportunities to coordinate with infrastructure improvement projects or take advantage of land availability could accelerate the implementation of specific projects. Therefore, the Action Plan is structured to support a flexible implementation strategy rather than a fixed sequence. Proponents can select the projects that align with anticipated revenues and take advantage of opportunities grants, complementary projects, availability of land) as they arise. ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 4 4-3 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Full implementation of this Action Plan could take 20 years or more. Basin conditions are likely to change over time due to changes in land use/land cover, new regulations, and new infrastructure, as well as implementation of the Action Plan projects. Before implementing a given Action Plan project, the project proponent should assess the situation to confirm that the project is still necessary and revise it as necessary to align with current conditions. The Action Plan projects are designed to alter the dynamic processes that are contributing excess sediment loads to Clarks Creek. Monitoring should be conducted during Action Plan implementation to evaluate changes in channel conditions and confirm that the implemented projects are functioning as intended (see Section 4.3). The monitoring results should help determine whether the concepts for the remaining unbuilt projects should be modified to enhance their effectiveness and/or reduce costs. 4.3 Monitoring and Adaptive Management This Action Plan describes a range of projects that are intended to reduce sediment loads to Clarks Creek. These projects are designed to alter the dynamic processes that are contributing to excess sediment loads. Creek channel conditions should be monitored during Action Plan implementation to evaluate the impacts of the projects on channel stability and sediment, and help determine whether the concepts for the remaining unbuilt projects should be modified to enhance effectiveness or reduce costs. Channel monitoring should begin after the initial Action Plan projects have been constructed. The monitoring program should include the elements outlined below. • Geomorphic reconnaissance: Geomorphic reconnaissance should be performed following project implementation to document channel conditions in the potentially affected reaches. The reconnaissance should be done using the same methods Inter-Fluve used to perform the 2011 geomorphic reconnaissance (see Appendix The affected reaches should be inspected once per year for 3 to 5 years and as soon as possible after large (greater than 5-year recurrence interval) storm events. Comparing the post-project channel conditions to 2011 channel conditions may help discern the effects of the Action Plan projects. • Cross-section survey: The cross-sections established for this project should be re-surveyed every 5 to 10 years to assess changes in channel geometry. Appendix B contains the 2011 survey data for each cross-section. The data from the re-survey can be compared to the baseline (2011) survey in order to discern changes in the channel. • Channel photographs: Permanent photo points should be established at each cross-section to document upstream and channel conditions. Photographs should be taken during each cross-section survey. Comparison of photos from different points in time may help identify changes in the channel. If the channel monitoring identifies potential problems, focused investigations and analyses may be needed to evaluate the cause(s) and support development of adaptive management measures. Additional investigations could include survey of new cross-sections, pebble counts, and MFAs. ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 4 4-4 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Project: Rody Creek Channel Stabilization ID: Pr01 Location: Rody Creek beginning near 80th Street East and ending approximately 500 feet Stream: Rody Creek Project Cost: $1,109,000 Jurisdiction: Pierce County Source Reduction: 6.7 tons/year Proj. Type: Channel stabilization (roughening) Reduction-cost Score: 0.8 Target: Degrading stream reach Flow Control Benefit: Low Narrative During the 2011 field investigation, moderate channel incision was observed in this reach. The recommended project is to stabilize this reach by roughening the channel within the degraded reach (approximately 500 linear feet) to reduce continued degradation and transport of sediment into the lower reaches of Rody Creek. A stabilization project was identified in Pierce County’s 2009 Clear/Clarks Creek Basin Plan to address potential property damage from failing stream bank stabilization measures in this vicinity (Project CIP03-RY-SBS02). Pierce County is currently designing this project. This fact sheet should be revised after Pierce County has completed its 30% design. Conceptual Design • 500 LF of roughened channel using a mixture of large boulders, cobbles, gravel, sand, and large wood. • Roughened area assumed to be approximately 25 feet wide to accommodate up to 100-year discharge. • A mobile hydraulic crane could be used to place roughening material from outside the stream channel. • Channel roughening cost assumed to be $200 per ton of material placed, based on recent project experience. • Cost estimate assumes 600 LF of temporary access road would need to be constructed at $200 per linear foot. • Cost estimate includes erosion/water pollution mitigation during in-stream work; use lump sum of $30,000. • Cost estimate includes a site survey (assumed $6,000 per acre). • Assumed lump sum of $50,000 for equipment rental and operation. • Assumed all project activities can be completed within easements; no land acquisition. Considerations for Implementation • A Hydraulic Project Approval (HPA) permit will need to be obtained from the Washington State Department of Fish and Wildlife (WDFW). • This project will require a Section 404 permit (for discharge of dredged or fill materials to waters of the U.S.) and a Section 401 water quality certification obtained from the Washington State Department of Ecology. Additionally, due to the presence of Endangered Species Act (ESA) listed species in Clark’s Creek, a Section 7 consultation will be required to ensure that the project does not jeopardize listed species. • This project will require compliance with the State Environmental Policy Act (SEPA) as well as local critical areas codes and ordinances. • Depending on the time of year, efforts for dewatering and/or fish removal may be needed. • For the construction phase, access and staging areas will be critical. Locations will need to be identified for storing material and placing a crane such that material can be delivered to the channel from above without a disturbance to the surrounding riparian area and adjacent hill slopes. • Easement may be required to provide construction and maintenance access, and a clearing and grading permit may be necessary for construction of the temporary access road. The temporary access road will be restored and revegetated upon completion of the project. ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 4 4-5 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Project Cost Estimate Item Unit Unit Cost Quantity Cost Erosion and water pollution control, mitigation for in-stream work LS 30,000 1 30,000 Site survey AC 6,000 1.1 7,000 Temporary access road LF 200 600 120,000 Streambed roughening mixture (boulder, cobble, wood, gravel, sand) TON 200 1,850 370,000 Riparian planting (restoration after access road removal) LF 150 600 90,000 Equipment rental and operation LS 50,000 1 50,000 Subtotal 667,000 Contractor overhead, profit, and mobilization 10% 67,000 Washington State sales tax 0 Construction contingency 20% 147,000 Subtotal construction costs 881,000 Administration, engineering design, permitting 30% 200,000 Land acquisition and easements LS 27,500 Total cost 1,109,000 - ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 4 4-6 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Project: Diru Creek Bank Stabilization ID: Pr02 Location: Diru Creek upstream of 72nd Street East Stream: Diru Creek Project Cost: $194,000 Jurisdiction: Pierce County Source Reduction: 7.7 tons/year Proj. Type: Channel stabilization (banks) Reduction-cost Score: 5.5 Target: Eroding stream banks Flow Control Benefit: Low Narrative Current channel conditions were evaluated as part of this study in 2011, and the current channel appears to be relatively stable, with large wood complexes storing sediment within the channel already in place. Only moderate bank erosion was observed upstream of 72nd Street E. The recommendation for Diru Creek is to use woody material and riparian plantings to provide additional bank stability in this reach (approximately 700 LF). This is a low cost alternative designed to provide bank stability and reduced sedimentation in a reach that appears to be relatively stable. This reach does not require more extensive stabilization techniques at this point in time. Pierce County’s 2009 Clear/Clarks Creek Basin Plan included a project to stabilize the stream channel of 72nd Street where channel down cutting was observed at the time of their field reconnaissance (Project CIP03-DU-SBS01). Pierce County is currently designing this project. This fact sheet should be revised after Pierce County has completed its 30% design. Conceptual Design • Project consists of 700 LF of bank stabilization using woody material and riparian plantings; assumed $50 per linear foot. • Cost estimate includes erosion/water pollution mitigation during in-stream work; use lump sum of $30,000. • Cost estimate includes a site survey (assumed $6,000 per acre). • Assumed lump sum of $50,000 for equipment rental and operation. • No land acquisition required for this project. Considerations for Implementation • A predesign study should be conducted to determine plant selection for achieving stable banks. • This project will require compliance with the State Environmental Policy Act (SEPA) as well as local critical areas codes and ordinances. ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 4 4-7 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Project Cost Estimate Item Unit Unit Cost Quantity Cost Erosion and water pollution control, mitigation for in-stream work LS 30,000 1 30,000 Site survey AC 6,000 0.8 5,000 Wood and riparian planting along banks LF 50 700 35,000 Equipment rental and operation LS 50,000 1 50,000 Subtotal 120,000 Contractor overhead, profit, and mobilization 10% 12,000 Washington State sales tax 0 Construction contingency 20% 26,000 Subtotal construction costs 158,000 Administration, engineering design, permitting 30% 36,000 Land acquisition and easements 0 Total cost 194,000 - ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 4 4-8 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Project: Woodland Creek Channel Stabilization: Lower ID: Pr03 Location: Woodland Creek of 80th Street East Stream: Woodland Creek Project Cost: $571,000 Jurisdiction: Pierce County Source Reduction: 13.5 tons/year Proj. Type: Channel stabilization (restoration) Reduction-cost Score: 3.3 Target: Degrading stream reach Flow Control Benefit: Low Narrative During the 2011 field investigation, it was noted that there is incision about 3 feet deep, with no riparian buffer located on the east side of the channel, immediately of 80th Street E. The recommended project is to stabilize this reach by installing grade control and channel roughening features such as large wood. Additionally, woody vegetation would be planted on the banks and adjacent field on the east side of the channel for additional stabilization. This project will provide reduced stream bank and bed sediment sources from contributing to sedimentation, as well as an improved riparian habitat and floodplain connection. Pierce County’s 2009 Clear/Clarks Creek Basin Plan included a project to stabilize the stream channel of 80th Street where channel down cutting was observed at the time of their field reconnaissance (Project CIP03-WO-SBS02). Pierce County is currently designing this project. This fact sheet should be revised after Pierce County has completed its 30% design. Conceptual Design • 900 LF of stream restoration, including grade control, large woody debris, and habitat restoration. • Restoration cost assumed to be $250 per linear foot, based on recent project experience. • Large woody debris will be applied to provide hydraulic diversity and to enhance habitat for fish and other aquatic organisms. • Assumed the site can be accessed without construction of a temporary access road. • Cost estimate includes erosion/water pollution mitigation during in-stream work; use lump sum of $30,000. • Cost estimate includes a site survey (assumed $6,000 per acre). • Assumed lump sum of $50,000 for equipment rental and operation. • Assumed all project activities can be completed within easements; no land acquisition. Considerations for Implementation • A site-specific hydraulic analysis to evaluate sizes of in-stream structures will need to be conducted. • A Hydraulic Project Approval (HPA) permit will need to be obtained from the Washington State Department of Fish and Wildlife (WDFW). • This project will require a Section 404 permit (for discharge of dredged or fill materials to waters of the U.S.) and a Section 401 water quality certification obtained from the state Department of Ecology. Additionally, due to the presence of Endangered Species Act (ESA) listed species in Clark’s Creek a Section 7 consultation will be required to ensure the project does not jeopardize listed species. • This project will require compliance with the State Environmental Policy Act (SEPA) as well as local critical areas codes and ordinances. • Depending on the time of year, efforts for dewatering and/or fish removal may be needed. • For the construction phase, access and staging areas will be critical. Locations will need to be identified for storing material and placing a crane such that material can be delivered to the channel from above without a disturbance to the surrounding riparian area and adjacent hill slopes. • Easement may be required to provide construction and maintenance access, and a clearing and grading permit may be necessary for construction of the temporary access road. The temporary access road will be restored and revegetated upon completion of the project. ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 4 4-9 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Project Cost Estimate Item Unit Unit Cost Quantity Cost Erosion and water pollution control, mitigation for in-stream work LS 30,000 1 30,000 Site survey AC 6,000 1.03 6,200 Stream restoration (grade control and habitat restoration) LF 250 900 225,000 Equipment rental and operation LS 50,000 1 50,000 Subtotal 311,200 Contractor overhead, profit, and mobilization 10% 31,000 Washington State sales tax 0 Construction contingency 30% 103,000 Subtotal construction costs 445,200 Administration, engineering design, permitting 30% 93,000 Land acquisition and easements LS 32,000 Total cost 571,000 - ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 4 4-10 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Project: Woodland Creek Channel Stabilization: Upper ID: Pr04 Location: Woodland Creek of 84th Street Stream: Woodland Creek Project Cost: $1,033,000 Jurisdiction: Pierce County Source Reduction: 38.9 tons/year Proj. Type: Channel stabilization (roughening) Reduction-cost Score: 5.2 Target: Degrading stream reach Flow Control Benefit: Low Narrative High stream flows have caused channel down cutting with 5-foot- deep channel incision in the reach of 84th Street E. Local scour is observed at the outlet of the culvert under 84th Street E where a 12-foot-high cascade waterfall is located immediately Sedimentation within the channel and floodplain upstream of 80th Street E are caused by this upstream erosion activity. The recommended project is to stabilize this reach by roughening the channel within the degraded reach (approximately 700 LF) to reduce continued degradation and transport of sediment into the lower reaches of Woodland Creek. Channel roughening would be accomplished with natural material, such as large boulders, cobbles and gravel, and large wood. A mobile hydraulic crane would be used where possible to place material into the stream channel from above. Conceptual Design • 700 LF of roughened channel using a mixture of large boulders, cobbles, gravel, sand, and large wood. • Roughened area assumed to be approximately 25 feet wide to accommodate up to 100-year discharge. • A mobile hydraulic crane could be used to place roughening material from outside the stream channel. • Channel roughening cost assumed to be $200 per ton of material placed, based on recent project experience. • Assumed the site can be accessed without construction of a temporary access road. • Cost estimate includes erosion/water pollution mitigation during in-stream work; use lump sum of $30,000. • Cost estimate includes a site survey (assumed $4,000 per acre). • Assumed lump sum of $50,000 for equipment rental and operation. • Assumed all project activities can be completed within easements; no land acquisition. Considerations for Implementation • A Hydraulic Project Approval (HPA) permit will need to be obtained from the Washington State Department of Fish and Wildlife (WDFW). • This project will require a Section 404 permit (for discharge of dredged or fill materials to waters of the U.S.) and a Section 401 water quality certification obtained from the state Department of Ecology. Additionally, due to the presence of Endangered Species Act (ESA) listed species in Clark’s Creek a Section 7 consultation will be required to ensure the project does not jeopardize listed species. • This project will require compliance with the State Environmental Policy Act (SEPA) as well as local critical areas codes and ordinances. • Depending on the time of year, efforts for dewatering and/or fish removal may be needed. • For the construction phase, access and staging areas will be critical. Locations will need to be identified for storing material and placing a crane such that material can be delivered to the channel from above without a disturbance to the surrounding riparian area and adjacent hill slopes. • Easement may be required to provide construction and maintenance access, and a clearing and grading permit may be necessary for construction of the temporary access road. The temporary access road will be restored and revegetated upon completion of the project. ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 4 4-11 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Project Cost Estimate Item Unit Unit Cost Quantity Cost Erosion and water pollution control, mitigation for in-stream work LS 30,000 1 30,000 Site survey AC 4,000 2.6 11,000 Streambed roughening mixture (boulder, cobble, wood, gravel, sand) TON 200 2,590 518,000 Equipment rental and operation LS 50,000 1 50,000 Subtotal 609,000 Contractor overhead, profit, and mobilization 10% 61,000 Washington State sales tax 0 Construction contingency 20% 134,000 Subtotal construction costs 804,000 Administration, engineering design, permitting 30% 183,000 Land acquisition and easements 46,000 Total cost 1,033,000 - ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 4 4-12 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Project: Upper Clarks Creek Channel Stabilization ID: Pr05 Location: Upper Clarks Creek of 23rd Avenue SW Stream: Upper Clarks Creek Project Cost: $1,962,000 Jurisdiction: City of Puyallup Source Reduction: 77.0 tons/year Proj. Type: Channel stabilization (headcut repair and roughening) Reduction-cost Score: 5.4 Target: Degrading stream reach Flow Control Benefit: Low Narrative This project was identified during the field reconnaissance conducted in 2011. The upper reach of Clarks Creek is severely incised of 23rd Avenue SW. A 12-foot-high headcut is located approximately 120 feet of the road crossing and has the potential to migrate upstream toward the road. The recommended project in this location is to stabilize the headcut and roughen the channel in the incised reach for approximately 1,000 LF of channel to reduce continued channel degradation and transport of sediment into the lower reaches of Clarks Creek. Channel roughening would be accomplished with natural material, such as large boulders, cobbles, gravel, sand, and large wood. A mobile hydraulic crane would be used where possible to place material into the stream channel from above (either from 23rd Avenue SW and/or access points to the east or west of the channel). This project will reduce the risk to public infrastructure, including 23rd Avenue SW, which could eventually be threatened by erosion if the headcut continues to migrate upstream. This project could be completed in conjunction with project Pr06. Cost reductions would result from shared resources, such as the temporary access road. Conceptual Design • 100 LF of fill and roughened channel material (large boulders, cobbles, gravel, sand) at headcut. • 900 LF of roughened channel using a mixture of large boulders, cobbles, gravel, sand, and large wood. • Roughened area assumed to be approximately 25 feet wide to accommodate up to 100-year discharge. • A mobile hydraulic crane could be used to place roughening material from outside the stream channel. • Channel roughening cost assumed to be $200 per ton of material placed, based on recent project experience. • Cost estimate assumes 1,000 LF of temporary access road would need to be constructed ($200/LF). • Cost estimate includes erosion/water pollution mitigation during in-stream work; use lump sum of $30,000. • Cost estimate includes a site survey (assumed $4,000 per acre). • Assumed lump sum of $50,000 for equipment rental and operation. • No land acquisition required for this project. Considerations for Implementation • A Hydraulic Project Approval (HPA) permit will need to be obtained from the Washington State Department of Fish and Wildlife (WDFW). • This project will require a Section 404 permit (for discharge of dredged or fill materials to waters of the U.S.) and a Section 401 water quality certification obtained from the state Department of Ecology. Additionally, due to the presence of Endangered Species Act (ESA) listed species in Clark’s Creek a Section 7 consultation will be required to ensure the project does not jeopardize listed species. • This project will require compliance with the State Environmental Policy Act (SEPA) as well as local critical areas codes and ordinances. • Depending on the time of year, efforts for dewatering and/or fish removal may be needed. • For the construction phase, access and staging areas will be critical. Locations will need to be identified for storing material and placing a crane such that material can be delivered to the channel from above without a disturbance to the surrounding riparian area and adjacent hill slopes. • No easement required to provide construction access, and a clearing and grading permit may be necessary for construction of the temporary access road. The temporary access road will be restored and revegetated upon completion of the project. ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 4 4-13 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Project Cost Estimate Item Unit Unit Cost Quantity Cost Erosion and water pollution control, mitigation for in-stream work LS 30,000 1 30,000 Site survey AC 4,000 3.45 13,800 Temporary access road LF 200 1,000 200,000 Streambed roughening mixture (boulder, cobble, wood, gravel, sand) TON 200 4,070 814,000 Riparian planting (restoration after access road removal) LF 150 1,000 150,000 Equipment rental and operation LS 50,000 1 50,000 Subtotal 1,257,800 Contractor overhead, profit, and mobilization 5% 63,000 Washington State sales tax 0 Construction contingency 20% 264,000 Subtotal construction costs 1,584,800 Administration, engineering design, permitting 30% 377,000 Land acquisition and easements 0 Total cost 1,962,000 - ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 4 4-14 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Project: Upper Clarks Tributary Channel Stabilization ID: Pr06 Location: Tributary to Upper Clarks Creek of 23rd Avenue SW Stream: Upper Clarks Creek Project Cost: $1,146,000 Jurisdiction: City of Puyallup Source Reduction: 56.4 tons/year Proj. Type: Channel stabilization (roughening) Reduction-cost Score: 6.8 Target: Degrading stream reach Flow Control Benefit: Low Narrative This project was identified during field reconnaissance conducted in 2011. The tributary to Clarks Creek is currently incised up to 5 feet deep. The recommended project is to stabilize this reach by roughening the channel within the degraded incised reach (approximately 400 LF) to reduce continued degradation and transport of sediment into the lower reaches of Clarks Creek. Channel roughening would be accomplished with natural material, such as large boulders, cobbles and gravel, and large wood. A mobile hydraulic crane would be used where possible to place material into the stream channel from above. This project could be completed in conjunction with project Pr05. Cost reductions would result from shared resources, such as the temporary access road. Conceptual Design • 400 LF of roughened channel using a mixture of large boulders, cobbles, gravel, sand, and large wood. • Roughened area assumed to be approximately 25 feet wide to accommodate up to 100-year discharge. • A mobile hydraulic crane could be used to place roughening material from outside the stream channel. • Channel roughening cost assumed to be $200 per ton of material placed, based on recent project experience. • Cost estimate assumes 1,000 LF of temporary access road would need to be constructed at $200 per linear foot. • Riparian habitat features are not included in this project due to intermittent flow conditions; however, plantings will be required to restore area disturbed by access road (assumed $150 per linear foot). • Cost estimate includes erosion/water pollution mitigation during in-stream work; use lump sum of $30,000. • Cost estimate includes a site survey (assumed $6,000 per acre). • Assumed lump sum of $25,000 for equipment rental and operation. • Assumed all project activities can be completed within easements; no land acquisition. Considerations for Implementation • A Hydraulic Project Approval (HPA) permit will need to be obtained from the Washington State Department of Fish and Wildlife (WDFW). • This project will require a Section 404 permit (for discharge of dredged or fill materials to waters of the U.S.) and a Section 401 water quality certification obtained from the state Department of Ecology. Additionally, due to the presence of Endangered Species Act (ESA) listed species in Clark’s Creek a Section 7 consultation will be required to ensure the project does not jeopardize listed species. • This project will require compliance with the State Environmental Policy Act (SEPA) as well as local critical areas codes and ordinances. • Depending on the time of year, efforts for dewatering and/or fish removal may be needed. • For the construction phase, access and staging areas will be critical. Locations will need to be identified for storing material and placing a crane such that material can be delivered to the channel from above without a disturbance to the surrounding riparian area and adjacent hill slopes. • No easement required to provide construction access, and a clearing and grading permit may be necessary for construction of the temporary access road. The temporary access road will be restored and revegetated upon completion of the project. ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 4 4-15 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Project Cost Estimate Item Unit Unit Cost Quantity Cost Erosion and water pollution control, mitigation for in-stream work LS 30,000 1 30,000 Site survey AC 6,000 1 6,000 Temporary access road LF 200 1,000 200,000 Streambed roughening mixture (boulder, cobble, wood, gravel, sand) TON 200 1,480 296,000 Riparian planting (restoration after access road removal) LF 150 1,000 150,000 Equipment rental and operation LS 25,000 1 25,000 Subtotal 707,000 Contractor overhead, profit, and mobilization 10% 71,000 Washington State sales tax 0 Construction contingency 20% 156,000 Subtotal construction costs 934,000 Administration, engineering design, permitting 30% 212,000 Land acquisition and easements 0 Total cost 1,146,000 - ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 4 4-16 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Project: Silver Creek Channel Stabilization: Lower ID: Pr07 Location: Silver Creek upstream of 15th Avenue SW Stream: Silver Creek Project Cost: $366 ,000 Jurisdiction: City of Puyallup Source Reduction: 8.2 tons/year Proj. Type: Channel stabilization (restoration) Reduction-cost Score: 3.1 Target: Degrading stream reach Flow Control Benefit: Low Narrative This project was identified during the field reconnaissance conducted in 2011. Degraded channel conditions were observed upstream of 15th Avenue SW. The level of incision is less than what was observed in the upper reach near 23rd Avenue SW. The recommended project is to stabilize this reach by installing grade control and channel roughening features such as large wood. Additionally, woody vegetation would be planted on the banks and adjacent field on the east side of the channel for additional stabilization. Conceptual Design • 500 LF of stream restoration, including grade control, large woody debris, and habitat restoration. • Restoration cost assumed to be $250 per linear foot, based on recent project experience. • Large woody debris will be applied to provide hydraulic diversity and to enhance habitat for fish and other aquatic organisms. • Assumed the site can be accessed without construction of a temporary access road. • Cost estimate includes erosion/water pollution mitigation during in-stream work; use lump sum of $30,000. • Cost estimate includes a site survey (assumed $6,000 per acre). • Assumed lump sum of $25,000 for equipment rental and operation. • Assumed all project activities can be completed within easements; no land acquisition. Considerations for Implementation • A site-specific hydraulic analysis to evaluate sizes of in-stream structures will need to be conducted. • A Hydraulic Project Approval (HPA) permit will need to be obtained from the Washington State Department of Fish and Wildlife (WDFW). • This project will require a Section 404 permit (for discharge of dredged or fill materials to waters of the U.S.) and a Section 401 water quality certification obtained from the state Department of Ecology. Additionally, due to the presence of Endangered Species Act (ESA) listed species in Clark’s Creek a Section 7 consultation will be required to ensure the project does not jeopardize listed species. • This project will require compliance with the State Environmental Policy Act (SEPA) as well as local critical areas codes and ordinances. • Depending on the time of year, efforts for dewatering and/or fish removal may be needed. • For the construction phase, access and staging areas will be critical. Locations will need to be identified for storing material and placing a crane such that material can be delivered to the channel from above without a disturbance to the surrounding riparian area and adjacent hill slopes. • Easement may be required to provide construction and maintenance access, and a clearing and grading permit may be necessary for construction of the temporary access road. The temporary access road will be restored and revegetated upon completion of the project. ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 4 4-17 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Project Cost Estimate Item Unit Unit Cost Quantity Cost Erosion and water pollution control, mitigation for in-stream work LS 30,000 1 30,000 Site survey AC 6,000 1.2 7,000 Stream restoration (grade control and habitat restoration) LF 250 500 125,000 Equipment rental and operation LS 25,000 1 25,000 Subtotal 187,000 Contractor overhead, profit, and mobilization 10% 19,000 Washington State sales tax 0 Construction contingency 20% 62,000 Subtotal construction costs 268,000 Administration, engineering design, permitting 30% 75,000 Land acquisition and easements 23,000 Total cost 366,000 - ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 4 4-18 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Project: Silver Creek Channel Stabilization: Upper ID: Pr08 Location: Silver Creek of 23rd Avenue SW Stream: Silver Creek Project Cost: $769,000 Jurisdiction: City of Puyallup Source Reduction: 34.8 tons/year Proj. Type: Channel stabilization (roughening) Reduction-cost Score: 6.2 Target: Degrading stream reach Flow Control Benefit: Moderate Narrative This project was identified during the field reconnaissance conducted in 2011. The stream channel was found to be severely incised with steep banks. The recommended project is to stabilize this reach by roughening the channel within the degraded reach (approximately 500 LF) to reduce continued degradation and transport of sediment into the lower reaches of Woodland Creek. Channel roughening would be accomplished with natural material, such as large boulders, cobbles and gravel, and large wood. A mobile hydraulic crane would be used where possible to place material into the stream channel from above. Conceptual Design • 500 LF of roughened channel using a mixture of large boulders, cobbles, gravel, sand, and large wood. • Roughened area assumed to be approximately 25 feet wide to accommodate up to 100-year discharge. • A mobile hydraulic crane could be used to place roughening material from outside the stream channel. • Channel roughening cost assumed to be $200 per ton of material placed, based on recent project experience. • Assumed the site can be accessed without construction of a temporary access road. • Cost estimate includes erosion/water pollution mitigation during in-stream work; use lump sum of $30,000. • Cost estimate includes a site survey (assumed $6,000 per acre). • Assumed lump sum of $50,000 for equipment rental and operation. • Assumed all project activities can be completed within easements; no land acquisition. Considerations for Implementation • A Hydraulic Project Approval (HPA) permit will need to be obtained from the Washington State Department of Fish and Wildlife (WDFW). • This project will require a Section 404 permit (for discharge of dredged or fill materials to waters of the U.S.) and a Section 401 water quality certification obtained from the state Department of Ecology. Additionally, due to the presence of Endangered Species Act (ESA) listed species in Clark’s Creek a Section 7 consultation will be required to ensure the project does not jeopardize listed species. • This project will require compliance with the State Environmental Policy Act (SEPA) as well as local critical areas codes and ordinances. • Depending on the time of year, efforts for dewatering and/or fish removal may be needed. • For the construction phase, access and staging areas will be critical. Locations will need to be identified for storing material and placing a crane such that material can be delivered to the channel from above without a disturbance to the surrounding riparian area and adjacent hill slopes. • Easement may be required to provide construction and maintenance access, and a clearing and grading permit may be necessary for construction of the temporary access road. The temporary access road will be restored and revegetated upon completion of the project. ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 4 4-19 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Project Cost Estimate Item Unit Unit Cost Quantity Cost Erosion and water pollution control, mitigation for in-stream work LS 10,000 1 10,000 Site survey AC 6,000 1.2 7,000 Contractor staging area EA 20,000 1 20,000 Streambed roughening mixture (boulder, cobble, wood, gravel, sand) TON 200 1,850 370,000 Equipment rental and operation LS 50,000 1 50,000 Subtotal 457,000 Contractor overhead, profit, and mobilization 10% 46,000 Washington State sales tax 0 Construction contingency 20% 101,000 Subtotal construction costs 604,000 Administration, engineering design, permitting 30% 137,000 Land acquisition and easements 28,000 Total cost 769,000 - ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 4 4-20 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Project: Rody Creek Detention Facility Retrofit ID: Pr09 Location: Rody Creek south of 90th Street East Stream: Rody Creek Project Cost: $443,000 Jurisdiction: Pierce County Source Reduction: 4.4 tons/year Proj. Type: Regional detention facility (retrofit of existing facility) Reduction-cost Score: 1.4 Target: Flow control for Rody Creek Flow Control Benefit: High Narrative The purpose of this project is to retrofit the existing detention facility to achieve additional flow duration control and water quality treatment. Pierce County’s 2009 Clear/Clarks Creek Basin Plan included a project to retrofit the existing facility on Rody Creek to increase capacity and provide additional flow control benefits for stabilization projects (Project CIP03-RY-DP01). Pierce County is currently designing this project. This fact sheet should be revised after Pierce County has completed its 30% design. Only capital expenditures necessary to retrofit the detention pond were included in the cost estimate. Annual inspection and periodic maintenance would be necessary for the detention pond to function as designed. Annual inspection and maintenance costs may be on the order of 3%–5% of the capital cost. Conceptual Design • Expand pond size to approximately 34 acre-feet. • Add two wet cells for water quality treatment. • Excavation assumed to be $20 per cubic yard including haul. • A new pond outlet control structure will be required; assumed lump sum of $20,000. • Project assumed to include seeding and mulching, shrub plantings and tree plantings. • Cost estimate includes erosion/water pollution mitigation during in-stream work. Considerations for Implementation • Additional hydrologic analysis should be conducted to optimize flow and duration control benefits. • This project will require compliance with the State Environmental Policy Act (SEPA) as well as local critical areas codes and ordinances. • This project will require a clearing and grading permit. ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 4 4-21 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Project Cost Estimate Item Unit Unit Cost Quantity Cost Erosion and water pollution control LS 14,000 1 14,000 Excavation including haul CY 20 4,500 90,000 Embankment compaction CY 5 3,000 15,000 Pond outlet control structure EA 20,000 1 20,000 Seeding and mulching AC 4,500 5 22,000 Shrub plantings EA 150 266 40,000 Tree plantings EA 250 132 33,000 Spill Prevention, Control, and Countermeasure (SPCC) plan LS 3,000 1 3,000 Subtotal 237,000 Contractor overhead, profit, and mobilization 10% 24,000 Washington State sales tax 9.5% 25,000 Construction contingency 30% 86,000 Subtotal construction costs 372,000 Administration, engineering design, permitting 30% 71,000 Land acquisition and easements 0 Total cost 443,000 - ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 4 4-22 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Project: Diru Creek Detention Facility ID: Pr10 Location: North side of 84th Street East adjacent to Diru Creek Stream: Diru Creek Project Cost: $2,051,000 Jurisdiction: Pierce County Source Reduction: 5.9 tons/year Proj. Type: Regional detention facility Reduction-cost Score: 0.4 Target: Flow control for Diru Creek Flow Control Benefit: High Narrative Urbanization in the Diru Creek basin has increased runoff rates and durations, which has led to stream channel instability. Future development within the basin could exacerbate these conditions unless flow control measures are implemented. Construction of a detention facility would provide flow control benefits in lieu of onsite measures and reduce erosion potential in reaches. In addition, a detention pond facility could be configured to capture and remove sediments. A site for the detention facility was selected by visual inspection of aerial photography to identify one or more relatively undeveloped parcels upstream of the steepest stream reaches. Additional investigations should be conducted to assess site suitability, spatial and hydraulic constraints, and likelihood of acquisition. Pierce County’s 2009 Clear/Clarks Creek Basin Plan included a project to construct a regional detention facility on Diru Creek to provide flow control benefits for stabilization projects (Project CIP03-DU-DP01). Pierce County is currently designing this project. This fact sheet should be revised after Pierce County has completed its 30% design. Only capital expenditures necessary to construct the detention pond were included in the cost estimate. Annual inspection and periodic maintenance would be necessary for the detention pond to function as designed. Annual inspection and maintenance costs may be on the order of 3%–5% of the capital cost. Conceptual Design • Construct a 17-acre-foot detention facility on available site upstream of unstable stream reaches. Sizing for the conceptual design was based on an assumed available area and maximum storage depth of 6 feet; actual facility size should be based on site investigations and predesign studies. • Excavation assumed to be $20 per cubic yard including haul; excavated volume assumed to be 80% of storage plus 2 feet over-excavation. • Assumed 20% of storage obtained by constructing banks. • Access road will need to be constructed; $25,000 lump sum. • A pond outlet control structure will be constructed; assumed $8,000 lump sum. • Cost estimate includes erosion/water pollution mitigation during in-stream work; use lump sum of $10,000. • Cost estimate also includes riprap inlet/outlet, clearing and grubbing, seeding and mulching/ tree/shrubs. • Land acquisition costs based on assessed parcel values plus 50%. Considerations for Implementation • An in-line pond is likely to be difficult to permit; an off-line facility may need to be considered. Assumed off-line facility for cost estimate. • It was assumed that upstream flows can be routed through the pond by gravity. • Additional hydrologic analysis should be conducted to optimize flow and duration control benefits. • This project will require compliance with the State Environmental Policy Act (SEPA) as well as local critical areas codes and ordinances. • This project will need a clearing and grading permit. • A critical areas study may be needed (wetland delineation). • Access and staging areas will need to be developed for the construction phase. • High groundwater levels may be limit the depth of the pond and reduce the available storage. • Temporary erosion and sediment control may need to be applied. • Land acquisition and easements will be required. • Project could encompass multiple parcels and therefore require negotiations with multiple landowners. • Conduct stakeholder involvement to identify potential concerns vectors, safety) and incorporate mitigation into design. ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 4 4-23 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Project Cost Estimate Item Unit Unit Cost Quantity Cost Site survey AC 3,000 4 12,000 Erosion and water pollution control LS 10,000 1 10,000 Clearing and grubbing AC 3,000 4 12,000 Excavation including haul CY 20 31,834 637,000 Select borrow including haul TON 20 1,100 22,000 Embankment compaction CY 10 600 6,000 Quarry spalls (riprap) TON 35 86 3,000 Access road LS 25,000 1 25,000 Pond outlet control structure EA 8,000 1 8,000 Modifications to existing stormwater collection system LS 15,000 1 15,000 Seeding and mulching AC 4,500 4 18,000 Shrub plantings EA 150 332 50,000 Tree plantings EA 250 166 42,000 Chain link fence (Type 3) LF 30 430 43,000 Double 20-foot fence gate EA 2,000 1 2,000 Temporary traffic control DAY 300 30 9,000 Spill Prevention, Control, and Countermeasure (SPCC) plan LS 3,000 1 3,000 Subtotal 917,000 Contractor overhead, profit, and mobilization 10% 92,000 Washington State sales tax 9.5% 96,000 Construction contingency 30% 332,000 Subtotal construction costs 1,437,000 Administration, engineering design, permitting 30% 275,000 Land acquisition and easements $338,400 Total cost 2,051,000 - ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 4 4-24 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Project: Woodland Creek Detention Facility ID: Pr11 Location: Near 72nd Avenue East and 90th Street East Stream: Woodland Creek Project Cost: $5,748,000 Jurisdiction: Pierce County Source Reduction: 11.2 tons/year Proj. Type: Regional detention facility Reduction-cost Score: 0.3 Target: Flow control for Woodland Creek Flow Control Benefit: High Narrative Urbanization in the Woodland Creek basin has increased runoff rates and durations, which has led to stream channel instability. Future development within the basin could exacerbate these conditions unless flow control measures are implemented. Construction of a detention facility would provide flow control benefits in lieu of onsite measures and reduce erosion potential in reaches. In addition, a detention pond facility could be configured to capture and remove sediments. A site for the detention facility was selected by visual inspection of aerial photography to identify one or more relatively undeveloped parcels upstream of the steepest stream reaches. Additional investigations should be conducted to assess site suitability, spatial and hydraulic constraints, and likelihood of acquisition. Only capital expenditures necessary to construct the detention pond were included in the cost estimate. Annual inspection and periodic maintenance would be necessary for the detention pond to function as designed. Annual inspection and maintenance costs may be on the order of 3%–5% of the capital cost. Conceptual Design • Construct a 50-acre-foot detention facility on available site upstream of unstable stream reaches. Sizing for the conceptual design was based on an assumed available area and maximum storage depth of 6 feet; actual facility size should be based on site investigations and predesign studies. • Excavation assumed to be $20 per cubic yard including haul; excavated volume assumed to be 80% of storage plus 2 feet over-excavation. • Assumed 20% of storage obtained by constructing banks. • Access road will need to be constructed; $25,000 lump sum. • A pond outlet control structure will be constructed; assumed $8,000 lump sum. • Cost estimate includes erosion/water pollution mitigation during in-stream work; use lump sum of $10,000. • Cost estimate includes a site survey (assumed $3,000 per acre). • Cost estimate also includes riprap inlet/outlet, clearing and grubbing, seeding and mulching/ tree/shrubs. • Land acquisition costs based on assessed parcel values plus 50%. Considerations for Implementation • An in-line pond is likely to be difficult to permit; an off-line facility may need to be considered. Assumed off-line facility for cost estimate. • It was assumed that upstream flows can be routed through the pond by gravity. • Additional hydrologic analysis should be conducted to optimize flow and duration control benefits. • This project will require compliance with the State Environmental Policy Act (SEPA) as well as local critical areas codes and ordinances. • This project will need a clearing and grading permit. • A state dam safety permit would be required because the pond capacity would exceed 10 acre feet. A critical areas study may be needed (wetland delineation). • Access and staging areas will need to be developed for the construction phase. • High groundwater levels may be limit the depth of the pond and reduce the available storage. • Temporary erosion and sediment control may need to be applied. • Land acquisition and easements will be required. • Project could encompass multiple parcels and therefore require negotiations with multiple landowners. • Conduct stakeholder involvement to identify potential concerns vectors, safety) and incorporate mitigation into design. ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 4 4-25 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Project Cost Estimate Item Unit Unit Cost Quantity Cost Site survey AC 3,000 11.7 35,000 Erosion and water pollution control LS 48,000 1 48,000 Clearing and grubbing AC 3,000 11.7 35,000 Excavation including haul CY 20 105,543 2,111,000 Select borrow including haul TON 20 1,950 39,000 Embankment compaction CY 10 1,100 11,000 Quarry spalls (riprap) TON 35 86 3,000 Access road LS 25,000 1 25,000 Pond outlet control structure EA 8,000 1 8,000 Modifications to existing stormwater collection system LS 15,000 1 15,000 Seeding and mulching AC 4,500 11.7 52,000 Shrub plantings EA 150 567 85,000 Tree plantings EA 250 284 71,000 Chain link fence (Type 3) LF 30 2,430 73,000 Double 20-foot fence gate EA 2,000 1 2,000 Temporary traffic control DAY 300 30 9,000 Spill Prevention, Control, and Countermeasure (SPCC) plan LS 3,000 1 3,000 Subtotal 2,625,000 Contractor overhead, profit, and mobilization 10% 263,000 Washington State sales tax 9.5% 274,000 Construction contingency 30% 949,000 Subtotal construction costs 4,111,000 Administration, engineering design, permitting 30% 788,000 Land acquisition and easements $848,250 Total cost 5,748,000 - ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 4 4-26 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Project: Clarks Creek Detention Facility ID: Pr12 Location: Upstream of 23rd Avenue SW (96th Street E) near Fruitland Avenue E Stream: Clarks Creek Project Cost: $8,848,000 Jurisdiction: City of Puyallup Source Reduction: 5.1 tons/year Proj. Type: Regional detention facility Reduction-cost Score: 0.1 Target: Flow control for Clarks Creek Flow Control Benefit: High Narrative Urbanization in the Clarks Creek basin has increased runoff rates and durations, which has led to stream channel instability. Future development within the basin could exacerbate these conditions unless flow control measures are implemented. Construction of a detention facility would provide flow control benefits in lieu of onsite measures and reduce erosion potential in reaches. In addition, a detention pond facility could be configured to capture and remove sediments. A site for the detention facility was selected by visual inspection of aerial photography to identify one or more relatively undeveloped parcels upstream of the steepest stream reaches. Additional investigations should be conducted to assess site suitability, spatial and hydraulic constraints, and likelihood of acquisition. Only capital expenditures necessary to construct the detention pond were included in the cost estimate. Annual inspection and periodic maintenance would be necessary for the detention pond to function as designed. Annual inspection and maintenance costs may be on the order of 3%–5% of the capital cost. Conceptual Design • Construct an 80-acre-foot detention facility on available site upstream of unstable stream reaches. Sizing for the conceptual design was based on an assumed available area and maximum storage depth of 6 feet; actual facility size should be based on site investigations and predesign studies. • Excavation assumed to be $20 per cubic yard including haul; excavated volume assumed to be 80% of storage plus 2 feet over-excavation. • Assumed 20% of storage obtained by constructing banks. • Access road will need to be constructed; $25,000 lump sum. • A pond outlet control structure will be constructed; assumed $8,000 lump sum. • Cost estimate includes erosion/water pollution mitigation during in-stream work; use lump sum of $10,000. • Cost estimate includes a site survey (assumed $3,000 per acre). • Cost estimate also includes riprap inlet/outlet, clearing and grubbing, seeding and mulching/ tree/shrubs. • Land acquisition costs based on assessed parcel values plus 50%. Considerations for Implementation • An in-line pond is likely to be difficult to permit; an off-line facility may need to be considered. Assumed off-line facility for cost estimate. • It was assumed that upstream flows can be routed through the pond by gravity. • Additional hydrologic analysis should be conducted to optimize flow and duration control benefits. • This project will require compliance with the State Environmental Policy Act (SEPA) as well as local critical areas codes and ordinances. • This project will need a clearing and grading permit. • A critical areas study may be needed (wetland delineation). • Access and staging areas will need to be developed for the construction phase. • High groundwater levels may be limit the depth of the pond and reduce the available storage. • Temporary erosion and sediment control may need to be applied. • Land acquisition and easements will be required. • Project could encompass multiple parcels and therefore require negotiations with multiple landowners. • Conduct stakeholder involvement to identify potential concerns vectors, safety) and incorporate mitigation into design. ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 4 4-27 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Project Cost Estimate Item Unit Unit Cost Quantity Cost Site survey AC 3,000 17 50,000 Erosion and water pollution control LS 73,000 1 73,000 Clearing and grubbing AC 3,000 17 50,000 Excavation including haul CY 20 156,506 3,131,000 Select borrow including haul TON 20 2,337 47,000 Embankment compaction CY 10 1,263 13,000 Quarry spalls (riprap) TON 35 86 3,000 Access road LS 25,000 1 25,000 Pond outlet control structure EA 8,000 1 8,000 Modifications to existing stormwater collection system LS 15,000 1 15,000 Seeding and mulching AC 4,500 17 75,000 Shrub plantings EA 150 680 102,000 Tree plantings EA 250 340 85,000 Chain link fence (Type 3) LF 30 2,900 87,000 Double 20-foot fence gate EA 2,000 1 2,000 Temporary traffic control Day 300 30 9,000 Spill Prevention, Control, and Countermeasure (SPCC) plan LS 3,000 1 3,000 Subtotal 3,778,000 Contractor overhead, profit, and mobilization 10% 378,000 Washington State sales tax 9.5% 395,000 Construction contingency 30% 1,365,000 Subtotal construction costs 5,916,000 Administration, engineering design, permitting 30% 1,133,000 Land acquisition and easements $1,798,050 Total cost 8,848,000 - ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 4 4-28 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Project: Silver Creek Detention Facility ID: Pr13 Location: Near 13th Street SW and 23rd Avenue SE Stream: Silver Creek Project Cost: $6,640 ,000 Jurisdiction: City of Puyallup Source Reduction: 8.3 tons/year Proj. Type: Regional detention facility Reduction-cost Score: 0.2 Target: Flow control for Silver Creek Flow Control Benefit: High Narrative Urbanization in the Silver Creek basin has increased runoff rates and durations, which has led to stream channel instability. Future development within the basin could exacerbate these conditions unless flow control measures are implemented. Construction of a detention facility would provide flow control benefits in lieu of onsite measures and reduce erosion potential in reaches. In addition, a detention pond facility could be configured to capture and remove sediments. A site for the detention facility was selected by visual inspection of aerial photography to identify one or more relatively undeveloped parcels upstream of the steepest stream reaches. Additional investigations should be conducted to assess site suitability, spatial and hydraulic constraints, and likelihood of acquisition. Only capital expenditures necessary to construct the detention pond were included in the cost estimate. Annual inspection and periodic maintenance would be necessary for the detention pond to function as designed. Annual inspection and maintenance costs may be on the order of 3%–5% of the capital cost. Conceptual Design • Construct a 65-acre-foot detention facility on available site upstream of unstable stream reaches. Sizing for the conceptual design was based on an assumed available area and maximum storage depth of 6 feet; actual facility size should be based on site investigations and predesign studies. • Excavation assumed to be $20 per cubic yard including haul; excavated volume assumed to be 80% of storage plus 2 feet over-excavation. • Assumed 20% of storage obtained by constructing banks. • Access road will need to be constructed; $25,000 lump sum. • A pond outlet control structure will be constructed; assumed $8,000 lump sum. • Cost estimate includes erosion/water pollution mitigation during in-stream work; use lump sum of $10,000. • Cost estimate includes a site survey (assumed $3,000 per acre). • Cost estimate also includes riprap inlet/outlet, clearing and grubbing, seeding and mulching/ tree/shrubs. • Land acquisition costs based on assessed parcel values plus 50%. Considerations for Implementation • An in-line pond is likely to be difficult to permit; an off-line facility may need to be considered. Assumed off-line facility for cost estimate. • It was assumed that upstream flows can be routed through the pond by gravity. • Additional hydrologic analysis should be conducted to optimize flow and duration control benefits. • This project will require compliance with the State Environmental Policy Act (SEPA) as well as local critical areas codes and ordinances. • This project will need a clearing and grading permit. • A critical areas study may be needed (wetland delineation). • Access and staging areas will need to be developed for the construction phase. • High groundwater levels may be limit the depth of the pond and reduce the available storage. • Temporary erosion and sediment control may need to be applied. • Land acquisition and easements will be required. • Project could encompass multiple parcels and therefore require negotiations with multiple landowners. • Conduct stakeholder involvement to identify potential concerns vectors, safety) and incorporate mitigation into design. ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 4 4-29 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Project Cost Estimate Item Unit Unit Cost Quantity Cost Site survey AC 3,000 13 39,000 Erosion and water pollution control LS 55,000 1 55,000 Clearing and grubbing AC 3,000 13 39,000 Excavation including haul CY 20 120,603 2,413,000 Select borrow including haul TON 20 2,058 42,000 Embankment compaction CY 10 1,113 12,000 Quarry spalls (riprap) TON 35 86 3,000 Access road LS 25,000 1 25,000 Pond outlet control structure EA 8,000 1 8,000 Modifications to existing stormwater collection system LS 15,000 1 15,000 Seeding and mulching AC 4,500 13 59,000 Shrub plantings EA 150 607 91,000 Tree plantings EA 250 301 76,000 Chain link fence (Type 3) LF 30 2,600 78,000 Double 20-foot fence gate EA 2,000 1 2,000 Temporary traffic control Day 300 30 9,000 Spill Prevention, Control, and Countermeasure (SPCC) plan LS 3,000 1 3,000 Subtotal 2,969,000 Contractor overhead, profit, and mobilization 10% 297,000 Washington State sales tax 9.5% 310,000 Construction contingency 30% 1,073,000 Subtotal construction costs 4,649,000 Administration, engineering design, permitting 30% 891,000 Land acquisition and easements $1,099,650 Total cost 6,640,000 - ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 4 4-30 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Project: Hatchery Pond Retrofit (Sedimentation Basin) ID: Pr14 Location: WDFW State Fish Hatchery: Modify pond to capture and remove sediment Stream: Clarks Creek Project Cost: $472,000 Jurisdiction: WDFW Source Reduction: 9.5 tons/year Proj. Type: Sedimentation facility Reduction-cost Score: 2.8 Target: Sediment transported from Upper Clarks Creek Flow Control Benefit: Low Narrative This project was identified in Pierce County’s 2009 Clear/Clarks Creek Basin Plan (CKSP01). The purpose of this project is to retrofit the existing pond above the WDFW state fish hatchery to serve as a sedimentation basin. Sediment would be excavated from the existing facility and a control structure would be installed. Subsequent removal of sediment would be expected to be necessary, at a frequency dependent on upstream sediment loading rates. Only capital expenditures necessary to modify the hatchery pond were included in the cost estimate. Annual inspection and periodic dredging would be necessary when capacity is substantially reduced. Conceptual Design • Efforts to control and mitigate erosion and water pollution will be applied. • A stream diversion structure will be constructed. • A dewatering system will be developed for use during construction efforts. • An estimated volume of 5,000 cubic yards of material will need to be mechanically dredged. • The existing dam will need to be modified with a new control structure. • The existing access road will be extended to provide better site access for maintenance activities. • Riparian planting to restore the site will be conducted. • Approximately 300 LF of Type 3 chain link fence will be installed, as well as a 20-foot fence gate. • Land acquisition will not be required. • Annual maintenance will need to be conducted. Considerations for Implementation • A Hydraulic Project Approval (HPA) permit will need to be obtained from the Washington State Department of Fish and Wildlife (WDFW). • This project will require a Section 404 permit (for discharge of dredged or fill materials to waters of the U.S.) and a Section 401 water quality certification obtained from the state Department of Ecology. Additionally, due to the presence of Endangered Species Act (ESA) listed species in Clark’s Creek a Section 7 consultation will be required to ensure the project does not jeopardize listed species. • This project will require compliance with the State Environmental Policy Act (SEPA) as well as local critical areas codes and ordinances. • A critical areas study may be needed (wetland delineation). • A temporary stream flow bypass and/or fish removal may need to be implemented during construction. ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 4 4-31 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Project Cost Estimate Item Unit Unit Cost Quantity Cost Erosion and water pollution control LS 10,000 1 10,000 Stream diversion LS 30,000 1 30,000 Dewatering system LS 25,000 1 25,000 Mechanical dredging CY 20 5,170 104,000 Modification to outlet control structure EA 20,000 1 20,000 Access road LF 200 500 25,000 Riparian planting LF 150 233 35,000 Chain link fence (Type 3) LF 30 300 9,000 Double 20-foot fence gate EA 2,000 1 2,000 Spill Prevention, Control, and Countermeasure (SPCC) plan LS 3,000 1 3,000 Annual maintenance % 3 - 8,000 Subtotal 271,000 Contractor overhead, profit, and mobilization 10% 27,000 Washington State sales tax 9.5% 28,000 Construction contingency 20% 65,000 Subtotal construction costs 391,000 Administration, engineering design, permitting 30% 81,000 Land acquisition and easements 0 Total cost 472,000 - ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 4 4-32 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Project: 15th Street Stormwater Diversion ID: Pr15 Location: Pioneer Avenue stormwater pipe diverted north at 15th Street, running approximately 1,668 linear feet to 4th Avenue NW Stream: Storm drain to Clarks Creek Project Cost: $1,285,300 Jurisdiction: City of Puyallup Source Reduction: 54.9 tons/year Proj. Type: Stormwater diversion Reduction-cost Score: 5.9 Target: Upland sediments from stormwater runoff Flow Control Benefit: High Narrative This project was identified in the City of Puyallup’s 2012 Comprehensive Storm Drainage Plan (CIP-ST-1). This project would allow for diversion of downtown Puyallup stormwater flow directly to the Puyallup River. The diversion will occur at the intersection of 15th Street NW and W Pioneer Avenue. New stormwater conveyance, ranging in diameter from 48 to 60 inches, will be constructed along 15th Street NW to the Puyallup River outfall (City outfall 18). This project would be constructed in two phases. The first phase, conveyance construction north of 4th Avenue NW, has been constructed. The second phase includes construction of 48-inch-diameter conveyance from W Pioneer to 4th Avenue NW along 15th Street NW. A flow control vault will also be constructed at the point of diversion from existing storm conveyance on W Pioneer Avenue. The project also includes replacing existing storm, water, and sanitary infrastructure within the project limits. This project also includes street, potable water, and sanitary infrastructure components. Earlier phases of this project installed a Vortechs Model 9000 water quality treatment device. Completing this project will eliminate the discharge of untreated stormwater from the diversion area into Clarks Creek, and discharge of treated stormwater into the Puyallup River. Conceptual Design • Costs were adjusted to match the cost estimate developed in the City of Puyallup’s 2012 Comprehensive Storm Drainage Plan (CIP-ST-1). • The project costs do NOT include costs for components other than stormwater. Shared costs (general items and mobilization) are pro-rated for the stormwater component of the project • Traffic control, potholing, and dewatering activities will need to be conducted for this project. • An estimated 1,668 LF of 48-inch pipe will need to be installed; this activity will include the applicable excavation, shoring, and backfilling to meet the project objectives. • A diversion structure will need to be installed; assumed lump sum of $30,000. Considerations for Implementation • This project has already been designed; however, prior to construction the facility sizes and performance should be verified using calibrated hydrologic and hydraulic models (as proposed by CIP-ST-4). • City permits for work conducted in the right-of-way will need to be obtained. • City permits pertaining to new road construction will need to be obtained. • This project will require compliance with the State Environmental Policy Act (SEPA) as well as local critical areas codes and ordinances. • Land acquisition is not required; work will be conducted in the right-of-way. ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 4 4-33 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Project Cost Estimate Item Unit Unit Cost Quantity Cost 48-inch pipe install, excavation, shoring and backfill LF 479 1,668 799,200 Diversion structure LS 30,000 1 30,000 General items (traffic control, potholing, dewatering) LF 59 1,668 98,400 Subtotal 927,600 Contractor overhead, profit, and mobilization 7% 64,900 Washington State sales tax 9.5% 94,300 Construction contingency 10% 99,250 Subtotal construction costs 1,186,050 Administration, engineering design, permitting 10% 99,250 Land acquisition and easements 0 Total cost 1,285,300 - ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 4 4-34 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Project: 7th Avenue Stormwater Diversion ID: Pr16 Location: 7th Avenue stormwater pipe diverted north at 16th Street, running approximately 7,200 linear feet to the Puyallup River Stream: Storm drain to Clarks Creek Project Cost: $11,646,000 Jurisdiction: City of Puyallup Source Reduction: 31.1 tons/year Proj. Type: Stormwater diversion Reduction-cost Score: 0.4 Target: Upland sediments from stormwater runoff Flow Control Benefit: High Narrative The purpose of this project is to divert flows containing large amounts of total suspended solids from Clarks Creek to the Puyallup River, reducing erosion potential in Clarks Creek. If desired, this project could be expanded to handle flows from two existing pump stations that currently discharge to Meeker Creek. Conceptual Design • Costs are based on the 15th Street Diversion project costs extrapolated using the same costs per linear foot. • An estimated 3,300 LF of 48-inch pipe will need to be installed; this activity will include the applicable excavation, shoring, and backfilling to meet the project objectives. • Traffic control, potholing, and dewatering activities will need to be conducted for this project. • A diversion structure will need to be installed; assumed lump sum of $30,000. • Additional modifications to the stormwater system included; assumed lump sum of $30,000. • Include stormwater treatment costs for 35 acres of impervious surface (40% of total impervious area); the unit cost for this treatment was estimated based on the average per-acre costs for other stormwater treatment projects. • This project would require a new outfall to the Puyallup River as well as a backflow prevention device. Considerations for Implementation • City permits for work conducted in the right-of-way will need to be obtained. • City permits pertaining to new road construction will need to be obtained. • This project will require compliance with the State Environmental Policy Act (SEPA) as well as local critical areas codes and ordinances. • Land acquisition is not required; work will be conducted in the right-of-way. • Coordination with Burlington Northern Santa Fe (BNSF) railroad would be required to route a new outfall pipe under the railroad tracks. • Contingencies for this project are higher than average because of potential permitting and construction challenges with construction of a new outfall, • Hydrologic and hydraulic modeling are required for design development. ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 4 4-35 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Project Cost Estimate Item Unit Unit Cost Quantity Cost 48-inch pipe install, excavation, shoring and backfill LF 479 7,200 3,449,800 Diversion structure LS 30,000 1 30,000 General items (traffic control, potholing, dewatering) LF 59 7,200 424,800 Modifications to existing stormwater collection system LS 30,000 1 30,000 Stormwater treatment AC 50,500 35 1,783,300 Backflow prevention device Ea 15,000 1 15,000 Subtotal 5,732,900 Contractor overhead, profit, and mobilization 7% 402,000 Washington State sales tax 9.5% 584,000 Construction contingency 40% 2,458,000 Subtotal construction costs 9,188,000 Administration, engineering design, permitting 40% 2,458,000 Land acquisition and easements 0 Total cost 11,646,000 - ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 4 4-36 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Project: 72nd Street Stormwater Improvements ID: Pr17 Location: 72nd Street SW: Treat roadway runoff with storm filters Stream: Storm drain to Rody Creek Project Cost: $551,000 Jurisdiction: Pierce County Source Reduction: 0.8 tons/year Proj. Type: Stormwater treatment Reduction-cost Score: 0.2 Target: Upland sources from 72nd Street SW Flow Control Benefit: Low Narrative The purpose of this project is to provide water quality treatment using vaults equipped with StormFilters™ that are designed to remove TSS (total suspended solids). Pierce County is currently designing this project. This fact sheet should be revised after Pierce County has completed its 30% design. Conceptual Design • Install StormFilter™ prefabricated vault to meet water quality treatment requirements for 12 acres of roadway; sized to treat approximately 2 cfs using 51 medium head cartridges. • Existing structure will be modified to split flow to the treatment facility. • An estimated 550 LF of 12-inch-diameter buried storm sewer pipe, plus an additional 300 LF of aboveground pipe will need to be installed. • Excavation assumed to be $20 per cubic yard including haul. • Gravel backfill assumed to be $40 per ton including haul. • Cost estimate includes erosion/water pollution mitigation during in-stream work; use lump sum of $10,000. • Modifications to the existing stormwater collection system will be required. • Land acquisition is not required. Work will be conducted in the right-of-way. • Additional costs include pavement repair, miscellaneous site restoration, and traffic control. Considerations for Implementation • This project will require compliance with the State Environmental Policy Act (SEPA) as well as local critical areas codes and ordinances. • Long-term maintenance plans and schedules to be coordinated with the Pierce County Road Maintenance crews will need to be developed. • The incorporation of StormFilters™ with other roadway improvement projects will need to be considered. • The continual maintenance and costs of ensuring the adequate treatment capacity of these structures will need to be considered. ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 4 4-37 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Project Cost Estimate Item Unit Unit Cost Quantity Cost Erosion and water pollution control LS 10,000 1 10,000 Excavation including haul CY 20 550 11,000 Gravel backfill including haul TON 40 1,950 78,000 Storm filters and vault EA 150,000 1 150,000 Modify existing structure to split flow EA 20,000 1 20,000 Schedule A storm sewer pipe 12-inch diameter LF 45 867 39,000 Connecting to existing drainage EA 1,000 2 2,000 HMA Cl 1/2-inch for pavement repair TON 130 130 17,000 Site restoration EA 10,000 1 10,000 Temporary traffic control Day 300 10 3,000 Subtotal 340,000 Contractor overhead, profit, and mobilization 18% 61,000 Washington State sales tax 9.5% 38,000 Construction contingency 10% 44,000 Subtotal construction costs 483,000 Administration, engineering design, permitting 20% 68,000 Land acquisition and easements 0 Total cost 551,000 - ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 4 4-38 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Project: North Pioneer Stormwater Treatment Facility ID: Pr18 Location: Stormwater outfall to Clarks Creek near W Pioneer Avenue (north side of the street) Stream: Storm drain to Clarks Creek Project Cost: $187,000 Jurisdiction: City of Puyallup Source Reduction: 2.3 tons/year Proj. Type: Stormwater treatment Reduction-cost Score: 1.7 Target: Upland sediment from stormwater runoff Flow Control Benefit: Low Narrative The purpose of this project is to provide water quality treatment using vaults equipped with StormFilters™ and hydrodynamic separators (HDS) that are designed to remove TSS (total suspended solids). This series of treatment facilities would be installed at an outfall that discharges to Clarks Creek near W Pioneer Avenue. Conceptual Design • Install StormFilter™ prefabricated vault and hydrodynamic separator to treat approximately 136 gallons per minute using 19 medium head cartridges. • Cost estimate includes prefabricated flow splitter at $5,500 (installed). • An estimated 200 LF of 12-inch-diameter Schedule A storm sewer pipe will need to be installed. This activity will include the applicable excavation, shoring, and backfilling. • Excavation assumed to be $20 per cubic yard including haul. • Gravel backfill assumed to be $40 per ton including haul. • Cost estimate includes erosion/water pollution mitigation during in-stream work; use lump sum of $10,000. • Modifications to the existing stormwater collection system will be required. • Land acquisition is not required. Work will be conducted in the right-of-way. • Additional costs include pavement repair, miscellaneous site restoration, and traffic control. Considerations for Implementation • City permits for work conducted in the right-of-way will need to be obtained. • City permits pertaining to new road construction will need to be obtained. • This project will require compliance with the State Environmental Policy Act (SEPA) as well as local critical areas codes and ordinances. • Long-term maintenance plans and schedules to be coordinated with the City road crews will need to be developed. • The incorporation of StormFilters™ with other roadway improvement projects will need to be considered. • The continual maintenance and costs of ensuring the adequate treatment capacity of these structures will need to be considered. ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 4 4-39 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Project Cost Estimate Item Unit Unit Cost Quantity Cost Erosion and water pollution control LS 10,000 1 10,000 Excavation including haul CY 20 200 4,000 Gravel backfill including haul TON 40 475 19,000 Hydrodynamic separator EA 20,000 1 20,000 Storm filter EA 35,000 1 35,000 Flow splitter EA 6,000 1 6,000 Schedule A storm sewer pipe 12-inch diameter LF 45 200 9,000 Connect to existing drainage EA 1,000 2 2,000 HMA Cl 1/2-inch for pavement repair TON 130 31 4,000 Site restoration EA 3,000 1 3,000 Temporary traffic control Day 300 10 3,000 Subtotal 115,000 Contractor overhead, profit, and mobilization 18% 21,000 Washington State sales tax 9.5% 13,000 Construction contingency 10% 15,000 Subtotal construction costs 164,000 Administration, engineering design, permitting 20% 23,000 Land acquisition and easements 0 Total cost 187,000 - ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 4 4-40 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Project: South Pioneer Stormwater Treatment Facility ID: Pr19 Location: Stormwater outfall to Clarks Creek near W Pioneer Avenue (south side of the street) Stream: Storm drain to Clarks Creek Project Cost: $173,000 Jurisdiction: City of Puyallup Source Reduction: 1.4 tons/year Proj. Type: Stormwater treatment Reduction-cost Score: 1.1 Target: Upland sediment from stormwater runoff Flow Control Benefit: Low Narrative The purpose of this project is to provide water quality treatment using vaults equipped with StormFilters™ and hydrodynamic separators (HDS) that are designed to remove TSS (total suspended solids). This series of treatment facilities would be installed at an outfall that discharges to Clarks Creek near W Pioneer Avenue. Conceptual Design • Install StormFilter™ prefabricated vault and hydrodynamic separator to treat approximately 100 gallons per minute using 14 medium head cartridges. • Cost estimate includes prefabricated flow splitter at $5,500 (installed). • An estimated 200 LF of 12-inch-diameter Schedule A storm sewer pipe will need to be installed. This activity will include the applicable excavation, shoring, and backfilling. • Excavation assumed to be $20 per cubic yard including haul. • Gravel backfill assumed to be $40 per ton including haul. • Cost estimate includes erosion/water pollution mitigation during in-stream work; use lump sum of $10,000. • Modifications to the existing stormwater collection system will be required. • Land acquisition is not required. Work will be conducted in the right-of-way. • Additional costs include pavement repair, miscellaneous site restoration, and traffic control. Considerations for Implementation • City permits for work conducted in the right-of-way will need to be obtained. • City permits pertaining to new road construction will need to be obtained. • This project will require compliance with the State Environmental Policy Act (SEPA) as well as local critical areas codes and ordinances. • Long-term maintenance plans and schedules to be coordinated with the City road crews will need to be developed. • The incorporation of StormFilters™ with other roadway improvement projects will need to be considered. • The continual maintenance and costs of ensuring the adequate treatment capacity of these structures will need to be considered. ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 4 4-41 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Project Cost Estimate Item Unit Unit Cost Quantity Cost Erosion and water pollution control LS 10,000 1 10,000 Excavation including haul CY 20 200 4,000 Gravel backfill including haul TON 40 475 19,000 Hydrodynamic separator EA 20,000 1 20,000 Storm filter EA 27,000 1 27,000 Flow splitter EA 6,000 1 6,000 Schedule A storm sewer pipe 12-inch diameter LF 45 200 9,000 Connect to existing drainage EA 1,000 2 2,000 HMA Cl 1/2-inch for pavement repair TON 130 31 4,000 Site restoration EA 3,000 1 3,000 Temporary traffic control Day 300 10 3,000 Subtotal 107,000 Contractor overhead, profit, and mobilization 18% 19,000 Washington State sales tax 9.5% 12,000 Construction contingency 10% 14,000 Subtotal construction costs 152,000 Administration, engineering design, permitting 20% 21,000 Land acquisition and easements 0 Total cost 173,000 - ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 4 4-42 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Project: 16th Street SW Stormwater Treatment Facility ID: Pr20 Location: Stormwater outfall to Meeker Creek near 16th Street SW Stream: Storm drain to Meeker Creek Project Cost: $157,000 Jurisdiction: City of Puyallup Source Reduction: 0.8 tons/year Proj. Type: Stormwater treatment Reduction-cost Score: 0.7 Target: Upland sediment from stormwater runoff Flow Control Benefit: Low Narrative The purpose of this project is to provide water quality treatment using vaults equipped with StormFilters™ and hydrodynamic separators (HDS) that are designed to remove TSS (total suspended solids). This series of treatment facilities would be installed at an outfall that discharges to Meeker Creek near 16th Street SW. Conceptual Design • Install StormFilter™ prefabricated vault and hydrodynamic separator to treat approximately 55 gallons per minute using 8 medium head cartridges. • Cost estimate includes prefabricated flow splitter at $5,500 (installed). • An estimated 200 LF of 12-inch-diameter Schedule A storm sewer pipe will need to be installed. This activity will include the applicable excavation, shoring, and backfilling. • Excavation assumed to be $20 per cubic yard including haul. • Gravel backfill assumed to be $40 per ton including haul. • Cost estimate includes erosion/water pollution mitigation during in-stream work; use lump sum of $10,000. • Modifications to the existing stormwater collection system will be required. • Land acquisition is not required. Work will be conducted in the right-of-way. • Additional costs include pavement repair, miscellaneous site restoration, and traffic control. Considerations for Implementation • City permits for work conducted in the right-of-way will need to be obtained. • City permits pertaining to new road construction will need to be obtained. • This project will require compliance with the State Environmental Policy Act (SEPA) as well as local critical areas codes and ordinances. • Long-term maintenance plans and schedules to be coordinated with the City road crews will need to be developed. • The incorporation of StormFilters™ with other roadway improvement projects will need to be considered. • The continual maintenance and costs of ensuring the adequate treatment capacity of these structures will need to be considered. ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 4 4-43 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Project Cost Estimate Item Unit Unit Cost Quantity Cost Erosion and water pollution control LS 10,000 1 10,000 Excavation including haul CY 20 200 4,000 Gravel backfill including haul TON 40 475 19,000 Hydrodynamic separator EA 20,000 1 20,000 Storm filter EA 17,000 1 17,000 Flow splitter EA 6,000 1 6,000 Schedule A storm sewer pipe 12-inch diameter LF 45 200 9,000 Connect to existing drainage EA 1,000 2 2,000 HMA Cl 1/2-inch for pavement repair TON 130 31 4,000 Site restoration EA 3,000 1 3,000 Temporary traffic control Day 300 10 3,000 Subtotal 97,000 Contractor overhead, profit, and mobilization 18% 17,000 Washington State sales tax 9.5% 11,000 Construction contingency 10% 13,000 Subtotal construction costs 138,000 Administration, engineering design, permitting 20% 19,000 Land acquisition and easements 0 Total cost 157,000 - ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 4 4-44 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Project: 14th Street SW Stormwater Treatment Facility ID: Pr21 Location: Stormwater outfall to Meeker Creek near 11th Street SW Stream: Storm drain to Meeker Creek Project Cost: $166,000 Jurisdiction: City of Puyallup Source Reduction: 1.1 tons/year Proj. Type: Stormwater treatment Reduction-cost Score: 0.9 Target: Upland sediment from stormwater runoff Flow Control Benefit: Low Narrative The purpose of this project is to provide water quality treatment using vaults equipped with StormFilters™ and hydrodynamic separators (HDS) that are designed to remove TSS (total suspended solids). This series of treatment facilities would be installed at an outfall that discharges to Meeker Creek near 14th Street SW. Conceptual Design • Install StormFilter™ prefabricated vault and hydrodynamic separator to treat approximately 75 gallons per minute using 11 medium head cartridges. • Cost estimate includes prefabricated flow splitter at $5,500 (installed). • An estimated 200 LF of 12-inch-diameter Schedule A storm sewer pipe will need to be installed. This activity will include the applicable excavation, shoring, and backfilling. • Excavation assumed to be $20 per cubic yard including haul. • Gravel backfill assumed to be $40 per ton including haul. • Cost estimate includes erosion/water pollution mitigation during in-stream work; use lump sum of $10,000. • Modifications to the existing stormwater collection system will be required. • Land acquisition is not required. Work will be conducted in the right-of-way. • Additional costs include pavement repair, miscellaneous site restoration, and traffic control. Considerations for Implementation • City permits for work conducted in the right-of-way will need to be obtained. • City permits pertaining to new road construction will need to be obtained. • This project will require compliance with the State Environmental Policy Act (SEPA) as well as local critical areas codes and ordinances. • Long-term maintenance plans and schedules to be coordinated with the City road crews will need to be developed. • The incorporation of StormFilters™ with other roadway improvement projects will need to be considered. • The continual maintenance and costs of ensuring the adequate treatment capacity of these structures will need to be considered. ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 4 4-45 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Project Cost Estimate Item Unit Unit Cost Quantity Cost Erosion and water pollution control LS 10,000 1 10,000 Excavation including haul CY 20 200 4,000 Gravel backfill including haul TON 40 475 19,000 Hydrodynamic separator EA 20,000 1 20,000 Storm filter EA 22,000 1 22,000 Flow splitter EA 6,000 1 6,000 Schedule A storm sewer pipe 12-inch diameter LF 45 200 9,000 Connect to existing drainage EA 1,000 2 2,000 HMA Cl 1/2-inch for pavement repair TON 130 31 4,000 Site restoration EA 3,000 1 3,000 Temporary traffic control Day 300 10 3,000 Subtotal 102,000 Contractor overhead, profit, and mobilization 18% 18,000 Washington State sales tax 9.5% 11,000 Construction contingency 10% 14,000 Subtotal construction costs 144,000 Administration, engineering design, permitting 20% 20,000 Land acquisition and easements 0 Total cost 164,000 - ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 4 4-46 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Project: Street Edge/Bioretention Retrofits for Secondary Roadways ID: Pr22 Location: Street-edge facilities along secondary streets within City of Puyallup Stream: Not Applicable/Distributed Project Cost: $1,607,000 Jurisdiction: City of Puyallup Source Reduction: 3.9 tons/year Proj. Type: Distributed facilities (low impact development) Reduction-cost Score: 0.3 Target: Upland sediment from stormwater runoff Flow Control Benefit: Moderate Narrative The purpose of this project is to retrofit existing secondary roadways with bioretention facilities for water quality treatment and flow control. Green infrastructure such as bioretention facilities function as filtration devices and can remove greater than 80% of suspended solids from stormwater runoff. Approximately 11 miles of roadway were assumed to be retrofitted. In some cases, the use of porous concrete may be considered in lieu of street edge bioretention facilities (see Project 23). Conceptual Design • Assumed average roadway width of 32 feet, multiplied by 11 miles results in approximately 43 acres of impervious surface. • Roadways areas were divided into well-drained and poorly drained soils, the latter requires facilities with under-drains. • GSI-Calc software (available at the Washington Stormwater Center http://www.wastormwatercenter.org/GSI_calc) was used to determine facility sizing. • Bioretention cells assumed to be 100 feet long by 8 feet wide, 1-foot ponding depth, 1.5-foot planting medium, and 1.5-foot gravel underdrain (where required). • A total of 84 cells are required (29 in well-drained soils, 55 in poorly drained soils). • Costs for each bioretention cell include an inlet grate, outlet structure with energy dissipation, and catch basin. • Land acquisition is not required; work would be conducted in the right-of-way. Considerations for Implementation • Projects will require coordination with City Transportation Department; to the extent possible, roadway retrofits should be incorporated with other roadway improvement projects. • Projects constructed within the right-of-way will require coordination with City road crews, City maintenance staff. • Long-term maintenance costs are not included in the cost estimate, but should be considered during design and implementation. ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 4 4-47 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Project Cost Estimate Item Unit Unit Cost Quantity Cost Inlet/outlet energy dissipation using quarry spall riprap EA 400.00 85 34,000 Underdrain pipe 8" dia. LF 15.50 5,484 85,000 Type 1 catch basin EA 1,200.00 84 101,000 Geotextile fabric over infiltration system SY 3.10 968 3,000 Excavation and haul CY 20.00 10,950 219,000 CB beehive grates EA 500.00 84 42,000 Underdrain rock TON 20.00 3,300 66,000 Rain garden plants EA 7.50 33,600 252,000 Hydroseeding (pond bottom, slopes, and perimeter) AC 2,250.00 1.78 4,000 Bioretention soil mix CY 34.00 3,735 127,000 Mulch CY 33.00 636 21,000 Subtotal 954,000 Contractor overhead, profit, and mobilization 13% 124,000 Washington State sales tax 9.5% 102,000 Construction contingency 20% 236,000 Subtotal construction costs 1,416,000 Administration, engineering design, permitting 20% 191,000 Land acquisition and easements 0 Total cost 1,607,000 - ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 4 4-48 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Project: Porous Concrete for Arterial Roadways ID: Pr23 Location: Arterial roadways within City of Puyallup Stream: Not Applicable/Distributed Project Cost: $6,663,000 Jurisdiction: City of Puyallup Source Reduction: 7.7 tons/year Proj. Type: Distributed facilities (low impact development) Reduction-cost Score: 0.2 Target: Upland sediment from stormwater runoff Flow Control Benefit: Moderate Narrative The purpose of this project is to resurface arterial roadways with porous concrete. Porous concrete allows rain to infiltrate into the roadway surface, thereby reducing the runoff rates and volumes. Reducing roadway runoff also reduces suspended sediments and other pollutants. *The cost estimate provided for this project is based on the net difference between porous concrete and conventional street construction costs. In other words, the cost to build an equivalent amount of roadway using conventional methods was subtracted from the total estimated cost for constructing porous concrete roadways, with the difference being the net cost increase. Note that this does not include the potential cost savings from avoiding the need to acquire additional land to meet flow control requirements by constructing onsite facilities. For example, if we assumed that we need to acquire 4 acres of land (approximately 10% of total area to be redeveloped) at a cost of $100,000 per acre, then using porous concrete would potentially save as much as $400,000 in land acquisition costs. Conceptual Design • Assumed average roadway width of 32 feet, multiplied by 10 miles results in approximately 38 acres of replaced roadway surface. • Project costs are based on the increase over conventional roadway resurfacing; i.e., the net cost for using pervious concrete was calculated by subtracting out the conventional costs. However, the conventional costs did not include the additional costs for mitigating the replaced impervious surface. • Under-drains only included for roadways in poorly drained soils. • The differential cost for pervious concrete was estimated to be approximately $4 per square foot higher than conventional concrete surfacing. • Land acquisition is not required; work would be conducted in the right-of-way. Considerations for Implementation • Projects will require coordination with City Transportation Department; to the extent possible, roadway retrofits should be incorporated with other roadway improvement projects. • Projects constructed within the right-of-way will require coordination with City road crews, City maintenance staff. • Long-term maintenance costs are not included in the cost estimate, but should be considered during design and implementation. ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 4 4-49 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Source: U.S. Environmental Protection Agency Project Cost Estimate Item Unit Unit Cost Quantity Cost Crushed surfacing TC (choker) 2" depth TON 30.00 13,800 414,000 Pervious concrete SF 4.75 1,667,160 7,919,000 Permeable base course aggregate (12") TON 25.00 82,720 2,068,000 Geotextile fabric (separation from native) SY 2.00 185,500 371,000 Underdrain pipe 8" dia. (only for areas with poorly drained soils) LF 16.00 34,100 546,000 Conventional street cost* (subtract to obtain net cost for pervious) SF 3.86 1,666,992 -6,435,000 Subtotal 4,883,000 Contractor overhead, profit, and mobilization 5% 244,000 Washington State sales tax 9.5% 487,000 Construction contingency 10% 561,000 Subtotal construction costs 6,175,000 Administration, engineering design, permitting 10% 488,000 Land acquisition and easements 0 Total cost 6,663,000 ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 4 4-50 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx ---PAGE BREAK--- 5-1 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Section 5 Limitations This document was prepared solely for Puyallup Tribe of Indians in accordance with professional standards at the time the services were performed and in accordance with the contract between Puyallup Tribe of Indians and Brown and Caldwell dated March 31, 2011. This document is governed by the specific scope of work authorized by Puyallup Tribe of Indians; it is not intended to be relied upon by any other party except for regulatory authorities contemplated by the scope of work. We have relied on information or instructions provided by Puyallup Tribe of Indians and other parties and, unless otherwise expressly indicated, have made no independent investigation as to the validity, completeness, or accuracy of such information. Further, Brown and Caldwell makes no warranties, express or implied, with respect to this document, except for those, if any, contained in the agreement pursuant to which the document was prepared. All data, drawings, documents, or information contained this report have been prepared exclusively for the person or entity to whom it was addressed and may not be relied upon by any other person or entity without the prior written consent of Brown and Caldwell unless otherwise provided by the Agreement pursuant to which these services were provided. ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Section 5 5-2 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx ---PAGE BREAK--- 6-1 Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Section 6 References Northwest Hydraulic Consultants Inc. (NHC). June 2005. Draft Flood Insurance Mapping Study for Clarks Creek near Puyallup, Washington Pierce County, WA and Incorporated Areas, Community Number – 530138. Prepared for the Federal Emergency Management Agency (FEMA) Prepared by Northwest Hydraulic Consultants Inc., 16300 Christensen Road, Suite 350, Seattle, Washington 98188-3418. Puget Sound LiDAR Consortium (PSLC). 2011. Digital Elevation Models. URL: http://pugetsoundlidar.ess.washington.edu/. Tetra Tech. April 4, 2012. Clarks Creek Sediment Study Watershed Model Report – Revised Draft. Prepared for the Puyallup Tribe of Indians by Tetra Tech, 3200 Chapel Hill-Nelson Hwy, Suite 105, PO Box 14409, Research Triangle Park, North Carolina 27709. Tetra Tech. May 11, 2012 Memorandum from Jon Butcher to Clarks Creek Project Team titled Clarks Creek Allocation Accounting. Prepared by Tetra Tech, 3200 Chapel Hill-Nelson Hwy, Suite 105, PO Box 14409, Research Triangle Park, North Carolina 27709. ---PAGE BREAK--- This page intentionally left blank. ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan DRAFT for review purposes only. Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan DRAFT (v15).docx Appendix A: Geomorphic Assessment and Sediment Analysis ---PAGE BREAK--- This page intentionally left blank. ---PAGE BREAK--- Technical Memorandum Limitations: This is a draft memorandum and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final report. This document was prepared solely for the Puyallup Tribe of Indians (PTI) in accordance with professional standards at the time the services were performed and in accordance with the contract between the PTI and Caldwell dated October 2011. This document is governed by the specific scope of work authorized by the PTI; it is not intended to be relied upon by any other party except for regulatory authorities contemplated by the scope of work. We have relied on information or instructions provided by the PTI and other parties and, unless otherwise expressly indicated, have made no independent investigation as to the validity, completeness, or accuracy of such information. 701 Pike Street, Suite 1200 Seattle, Washington 98101 Tel: [PHONE REDACTED] Fax: [PHONE REDACTED] Prepared for: The Puyallup Tribe of Indians Project Title: Clarks Creek Sediment Reduction Study Project No.: 140982.003 Subject: Field Investigations Date: October 24, 2011 To: Char Naylor, PTI Project Manager From: R. Victoria Zeledon, Brown and Caldwell Mike Milne, Brown and Caldwell ---PAGE BREAK--- Field Investigations 1 DRAFT for review purposes only. Use of contents on this sheet is subject to the limitations specified at the end of this document. FieldInvestigationsMemo mmvz (3).docx 1. Introduction The Puyallup Tribe of Indians (PTI) retained Brown and Caldwell (BC) to lead the development of an Action Plan aimed at reducing sediment loading to Clarks Creek. BC subcontracted with Inter-Fluve, Inc. to help evaluate geomorphic processes, sediment source areas, and sediment depositional areas. BC used the field reconnaissance observations to adjust locations for sediment sampling and hydraulic modeling. The hydraulic model was provided to the PTI’s contractor, Tetra Tech, to aid in development of the HSPF model for the study area. BC and PTI staff collected the sediment samples, which were sent to the Analytical Resources Inc. (lab) for analysis. The sample collection and analysis were performed in accordance with the Quality Assurance Project Plan for the Clarks Creek Sediment Reduction Study (QAPP) (Brown and Caldwell June 2011). This technical memorandum summarizes the results of the geomorphological assessment and sediment sampling. 2. Geomorphological Assessment The following section describes the geomorphological assessment of the Clarks Creek watershed conducted by Inter-Fluve, Inc. 2.1 Background Inter-Fluve staff Dan Miller P.E. and Mike Brunfelt L.G. conducted a field reconnaissance on June 20–22, 2011. The objective of the field reconnaissance was to identify erosional and depositional reaches and point sources of sediment, and to gain an understanding of existing geomorphic conditions. Major point sources of sediment, unstable reaches, and field-based adjustments to tentative survey cross-section locations were identified with a hand-held Garmin GPSMAP 76Cx global positioning system (GPS) navigator (accuracy no better than 10 feet). This technical memorandum is a summary of our field observations and understanding of existing geomorphic processes based on our review of existing studies, reports, maps, aerial photos, and field work completed to date. 2.2 Study Area Clarks Creek, which is a tributary to the Puyallup River, has a watershed of approximately 6,600 acres of rural and urban land use. It has four main tributaries: Rody, Diru, Woodland, and Silver Creeks. Each tributary (and Clarks Creek itself) runs in a general south-to-north direction toward the Puyallup River. Meeker Ditch runs down the Puyallup River Valley and delivers Silver Creek surface and storm drainage water to Clarks Creek. All tributaries combine with Clarks Creek within the Puyallup River Valley bottom. Clarks Creek flows into the Puyallup River near the 48th Street E Bridge. ---PAGE BREAK--- Field Investigations 2 DRAFT for review purposes only. Use of contents on this sheet is subject to the limitations specified at the end of this document. FieldInvestigationsMemo mmvz (3).docx 2.3 Existing Conditions The drop in elevation from the headwaters of the Clarks, Rody, Diru, Woodland, and Silver Creek watersheds to the Puyallup River valley bottom is approximately 450 feet. Creeks within the study area drain relatively flat upland surface topography before running down a steep glacial terrace that forms the southern boundary of the Puyallup River Valley within the study area. The terrace is composed of glacial advance outwash sand and gravels, glacial till, and recessional outwash sand and gravels. When eroded, these provide a substantial sediment supply for segments of each tributary and Clarks Creek as it flows out to the Puyallup River. There is a substantial groundwater base flow component to the hydrology of the Clarks Creek watershed. Clarks Creek and its tributaries have substantial gains in groundwater flow starting near the toe of the glacial outwash terrace and extending up the glacial terrace. In the case of Clarks Creek, these gains occur for a distance of approximately one-half mile. Water infiltrated in the upper watershed runs through an aquifer of gravel, sand, silt, and clay. The aquifer is expressed at the surface near the toe of the glacial terrace with several springs (Maplewood Spring is one example). Below the aquifer is a silt-clay confining unit and above it is Vashon till composed of unstratified clay, silt, cobbles, sand, and gravel. 2.4 Clarks Creek Clarks Creek was walked in the upstream direction from the Washington Department of Fish and Wildlife (WDFW) Puyallup Trout Hatchery to 96th Street E. An unnamed tributary east of Clarks Creek was then walked to its confluence with Clarks Creek upstream of Maplewood Springs. Segments of Clarks Creek were observed from the Puyallup River upstream to Clarks Creek Park at all major road crossings. The Clarks Creek channel bed is composed of gravel, cobble, sand, and silt substrate as it runs down the steeper glacial terrace. As it flows out onto the Puyallup River Valley floor, the bed transitions from larger gravel/cobble to smaller sand and silt near the toe of the glacial terrace. The reduction in particle size is primarily a function of the reduction in channel slope and channel confinement, resulting in the deposition of the larger sediment particle sizes. Based on visual observations at major road crossings, Clarks Creek appears capable of transporting sand and silt out to the Puyallup River. Quantitative analysis of sediment transport characteristics will be completed in later phases of this study. 2.4.1 Sediment Point Sources and Instability Major sediment source areas and instability within Clarks Creek are located in the steepest channel segments that run through confined, steeply sloped valleys that have eroded into the glacial terrace. The most actively eroding segments have nearly vertical valley walls composed of sand, silt, and small gravel. Currently, rotational slope failures and lateral stream migration into segments of unconsolidated glacial outwash appear to be the most common erosional processes delivering sediment to the channel. Areas of consolidated glacial till are slowing or metering the volume of sediment delivered over time. The speed of erosion and rate of sediment delivery are unknown, variable, and difficult to gauge due to the varied stability and material composition between layers of glacial till and outwash. A large head cut (12–15 feet) forms the upstream boundary of channel instability. The height of the head cut gives some indication of how much bed material has been previously removed over time. ---PAGE BREAK--- Field Investigations 3 DRAFT for review purposes only. Use of contents on this sheet is subject to the limitations specified at the end of this document. FieldInvestigationsMemo mmvz (3).docx Although vertical bed lowering appears to have produced substantial historical sediment supply, current supply appears more dominated by steep vertical and failing valley walls previously undermined by the channel head cut. Valley wall material is dominated by small gravel, sand, and silt that is mobilized and transported after entering the active channel. Large wood and vegetation locally store and reduce the rate of sediment transport. Major sediment source areas within Clarks Creek can be viewed in attached drawings. We observed no large head cuts within the unnamed tributary channel east of Clarks Creek. The degree of valley wall slope failure was relatively small and the degree of channel incision was approximately 3 feet. Historical streambank sediment yield was estimated based on field measurements of bed incision and bank erosion. The total eroded volume from Clarks Creek‘s streambanks was estimated at 8,730 cubic yards, with 5,340 cubic yards originating in the mainstem and 3,390 cubic yards in the east fork. Please refer to Attachment A for a description of the methodology adopted and the estimated sediment yield by reach. 2.4.2 Depositional Reaches A large area of deposition was identified upstream of a dam located near the Puyallup Trout Hatchery. The dam reservoir is nearly full of sediment, the channel above the reservoir is braided, and old stumps several hundred feet upstream are partially buried. These field conditions indicate that larger sediment particle sizes are not being transported and are depositing due to the change in slope caused by the dam. We estimate that it is possible that sediments consisting of pea-size gravel, sand, and silt are capable of making it past the nearly filled dam reservoir during flood flows. Based on visual observation, we estimate that source area sediments from the upper reaches of Clarks Creek could be up to 80 percent sand and silt. Immediately of the dam, the stream appears to be dynamically stable with no tendencies toward erosion or deposition. of the dam, channel slope is reduced as Clarks Creek encounters the Puyallup River Valley. Within most segments of the channel below the toe of the glacial terrace, sand and silt are significant components of channel bed substrate. Areas of temporary storage and deposition occur within and behind aquatic or riparian woody vegetation from the toe of the glacial terrace to the confluence with the Puyallup River. Field observations and knowledge of creek management indicates that the aquatic vegetation stores sediment and acts to occlude the channel enough to raise water surface elevations over time. 2.4.3 General Geomorphic Condition and Observations Clarks Creek exhibits signs of previous head cutting or stream bed lowering followed by lateral slope instability caused by bed lowering and removal of the toe of adjacent valley walls. To date, we have not been able to determine the exact timing and sequence behind the channel lowering and head cut observed in the field as we have found no firsthand local knowledge or quantitative historical information. However, we have surmised three possibilities that may play overlapping or combined roles in developing existing conditions in Clarks Creek and its tributaries. The first was identified in a historical map that shows the straightening of the Puyallup River in the early 1900s. Based on map measurements, more than 3 miles of Puyallup River channel length was lost immediately of the Clarks Creek’s confluence with the Puyallup River. The channel straightening, referred to as the Reservation Cutoff, is below another straightened segment, referred to as the Murphy Cutoff. The loss of this much channel length would have certainly decreased the base level of both the Puyallup River locally and caused Clarks Creek to fall off its former channel ---PAGE BREAK--- Field Investigations 4 DRAFT for review purposes only. Use of contents on this sheet is subject to the limitations specified at the end of this document. FieldInvestigationsMemo mmvz (3).docx bed down into the new lower elevation of the Puyallup River. The much steeper slope in Clarks Creek at the new lower-elevation, straightened Puyallup River confluence would have caused the bed substrate to erode in Clarks Creek. The steeper stream channel and subsequent erosion (head cut) would have worked its way upstream through Clarks Creek and its tributaries until finding substrate that could not be eroded at the steeper slope initiated by the Puyallup River lowering and straightening project. Based on this premise, the head cut we observed at the upstream boundary could be related to the initial Puyallup River straightening project in the early 1900s (see Figure Erosion and head cutting would have likely slowed as the watershed area and runoff energy decreased and larger existing particle sizes were encountered. However, during flood flows, the head cutting may have been more active and local instability more pronounced. Figure 1. Historical map showing Puyallup River straightening of Clarks Creek The straightened channel is referred to as the “Reservation Cut-Off” on the map. From PTI map files. Clarks Creek Straightened Puyallup River Channel ---PAGE BREAK--- Field Investigations 5 DRAFT for review purposes only. Use of contents on this sheet is subject to the limitations specified at the end of this document. FieldInvestigationsMemo mmvz (3).docx The second possibility we considered is that bed erosion and channel expansion from increased runoff caused by land clearing and development within the Clarks Creek watershed could have caused the observed conditions. Removal of forest cover likely increased runoff volumes and rates by reducing evapotranspiration, canopy interception, and forest floor storage. Creation of impervious surfaces, such as houses, roads, and parking lots, further increased runoff volumes and rates. If runoff energy is increased beyond channel thresholds, bed erosion and channel expansion occur. Bed erosion and lateral bank failures observed in Clarks Creek are consistent with elevated runoff caused by development activity and the growth of impervious surfaces within the watershed. Third, large regional winter storms and floods might have played a role in destabilizing adjacent hill slopes that were at or near instability thresholds. Relatively rare precipitation events could have created or rejuvenated instability in the channel and steep adjacent valley walls. Field and historical map evidence suggests that channel straightening resulting in head cutting and channel degradation, increases in impervious surface runoff, and large regional floods have possibly combined to destabilize Clarks Creek. 2.5 Rody Creek Rody Creek was walked from 84th Street E to Pioneer Way E 2.5.1 Sediment Point Sources and Instability Field observations indicate that Rody Creek has experienced approximately 3 feet of incision or down-cutting. Incision estimates were based on our estimates of head-cut height, degree of valley wall erosion, and comparisons with un-incised channel segments that existed upstream of head cuts and/or road crossings. With the exception of channel incision, the upstream half of Rody Creek is relatively stable. No substantial adjacent hill slope erosion and point sources were observed. Approximately 700 feet upstream of 72nd Street E, several springs deliver groundwater to the channel. At the spring outfalls, large hill slope failures have delivered gravel, silt, and sand to the channel. These failures, combined with previous incision, appear to have delivered large volumes of sediment to the channel. of 72nd Street E, one slope failure is located approximately 500 feet of the Pioneer Avenue culvert. No other large and recent point sources of sediment were observed in Rody Creek. The total eroded volume from Rody Creek’s bed and banks was estimated at 2,490 cubic yards (Attachment 2.5.2 Depositional Reaches Major zones of deposition in Rody Creek occur approximately 700 feet upstream of the 72nd Street E culvert inlet to the Puyallup River Valley floor. The deposition occurring upstream of 72nd Street E is caused by the culvert inlet and engineered concrete tower inlet structure that allows water to run into the culvert even as debris and sediment block and aggrade the channel. To have developed this structure is evidence that a problem with sediment and debris plugging the culvert inlet has been reoccurring through time. of 72nd Street E the channel deposition and aggradation from the sediment that has passed through the culvert is so great that the outlet of the pipe is partially buried. A braided channel condition exists of 72nd Street E that continues to Pioneer Avenue, where the channel ---PAGE BREAK--- Field Investigations 6 DRAFT for review purposes only. Use of contents on this sheet is subject to the limitations specified at the end of this document. FieldInvestigationsMemo mmvz (3).docx must pass through another road culvert. A cross-valley riprap weir, approximately 3 feet high, exists approximately 100 yards upstream of Pioneer Avenue. of Pioneer Avenue, the channel is also depositional and has aggraded to the point where the landowner of Pioneer Avenue has excavated out the channel and placed the spoils on the adjacent bank for a distance of approximately 500 feet. It appears that this activity may have occurred without a permit. A cease- and-desist letter was posted at this site. The substrate particle sizes in the channel from 72nd Street E to that observed below Pioneer Avenue slowly decreases from large gravel and cobble down to small gravel and sand. This is primarily due to a reduction in slope moving to the Puyallup River Valley and the large volume of sediment delivered to this reach of channel. The braided planform of the channel is indicative of the inability of the channel to transport the sediment load that is being delivered from upstream source areas. 2.5.3 General Geomorphic Condition and Observations Rody Creek shows processes and conditions very similar to those previously addressed in Clarks Creek. Regional incision following the straightening of the Puyallup River, impervious-surface-induced runoff, erosion, and regional flooding appear to have destabilized the channel and adjacent hill slopes. In the case of Rody Creek the majority of the most recent hill slope failures occur within the zone of groundwater gain. In comparison, most of the hill slope failures in Clarks Creek occur upstream of the zone of groundwater gain. Based on the large volume of sediment in the channel of 72nd Street E, we would expect to see continued high sediment delivery to reaches of Rody Creek below Pioneer Avenue all the way to the Clarks Creek confluence. Based on visual observations, most of the material sizes transported of Pioneer Avenue appear to be small gravels, sand, and silt. 2.6 Diru Creek Diru Creek was walked in the upstream direction from approximately 300 feet of Pioneer Avenue to 84th Street E. 2.6.1 Sediment Point Sources and Instability Field observations indicate that Diru Creek has experienced 1 to 2 feet of incision or channel bed down-cutting. Existing large wood material has formed jams that have successfully stored sediment upstream of them. Currently, no major point sources of sediment occur within the channel and only minor hill slope failures were observed. Diru Creek is relatively intact and stable as there are no major source areas for sediment. The existing channel and vegetative conditions indicate that the channel has not experienced hydrologic runoff high enough to substantially destabilize the bed and adjacent hill slopes. In Diru Creek, only 530 cubic yards of sediment were estimated to have been eroded from its banks over the years. 2.6.2 Depositional Reaches No significant sediment depositional reaches are located in Diru Creek. Local areas of deposition have occurred upstream of large wood jams that are currently storing previously eroded sediment. ---PAGE BREAK--- Field Investigations 7 DRAFT for review purposes only. Use of contents on this sheet is subject to the limitations specified at the end of this document. FieldInvestigationsMemo mmvz (3).docx 2.6.3 General Geomorphic Condition and Observations Based on field observations, Diru Creek has experienced some regional incision; however, the channel has been able to withstand previous degradation and no major hill slope failures have occurred. Diru Creek is in the best condition of all the stream channels observed and would benefit most from any activities that would reduce future impervious surface peak flow impacts that might be caused from future development. 2.7 Woodland Creek Segments of Woodland Creek were walked adjacent to the Puyallup Research and Extension Center upstream to 84th Street E. Segments of Woodland Creek were walked near Pioneer Avenue. 2.7.1 Sediment Point Sources and Instability Woodland Creek has experienced approximately 5 feet of incision; however, upstream of 80th Street E, the channel has not incised and is stable. The most degraded channel segment is the 1,200 feet of the 80th Street E culvert crossing. Within this segment, the channel has degraded and is expanding laterally. The steep vertical valley walls will continue to deliver small gravel, silt, and sand to Woodland Creek. The total eroded volume from Woodland Creek‘s streambanks was estimated at 2,150 cubic yards. 2.7.2 Depositional Reaches No major depositional areas are located within Woodland Creek until it runs onto the Puyallup River Valley floor, where the creek runs through a large reed canary grass wetland. The wetland, which runs on both sides of Pioneer Avenue, is very flat and poorly drained. The area provides a substantial sediment sink, and much of the sediment that is delivered from eroding upstream source areas is likely retained and stored in the wetland. 2.7.3 General Geomorphic Condition and Observations Woodland Creek shows significant incision and ongoing lateral bank erosion. Historical incision has been stopped at the 80th Street E culvert crossing. The crossing controls the grade for the upstream un-incised channel. Below the crossing, the channel continues to laterally erode glacial outwash gravel, sand, and silt. This activity will slowly continue until more stable bank angles are reached and become vegetated. The large reed canary grass wetland complex that Woodland Creek runs through is a natural sediment sink that appears to be storing and retaining large volumes of sediment. The wetland is large enough to continue to store substantial volumes of future sediment sources from steeper eroding segments of Woodland Creek. Therefore, the wetland provides a good buffer to reduce Woodland Creek-derived sediment to channel segments and Clarks Creek. 2.8 Silver Creek Silver Creek was walked from Meeker Ditch upstream to 19th Avenue SE and upstream and of 23rd Avenue SE approximately 500 feet. Silver Creek was also viewed from 104th Street E and tributary watershed/channel segments viewed from 5th Street SE. ---PAGE BREAK--- Field Investigations 8 DRAFT for review purposes only. Use of contents on this sheet is subject to the limitations specified at the end of this document. FieldInvestigationsMemo mmvz (3).docx 2.8.1 Sediment Point Sources and Instability Within the stream segments observed, Silver Creek has experienced approximately 3 to 4 feet of incision. No incision was observed at the 104th Street E road crossing. Upstream of 23rd Avenue SE, the creek reaches the top of the glacial terrace and the channel is no longer confined by steep valley walls. However, 3 to 4 feet of channel incision still exists. Below 23rd Avenue SE, the channel is steeper and confined as it drops off the top edge of the glacial terrace and descends to the Puyallup River Valley floor. Recent lateral erosion has destabilized adjacent valley walls and delivered large volumes of gravel, sand, and silt to the channel. In some locations, vertically eroded valley walls are below existing homes. If the valley walls continue to erode, the foundations of these homes would be at risk of becoming undermined and failing. A discussion with one homeowner indicated that discharge was thought to have increased in recent years and that the inlet to the 23rd Avenue SE culvert has been blocked by debris in the past. Efforts to remove these blockages have resulted in large short-term releases of water dammed upstream of the inlet. The rapid, high-pressure release of water following blockage removal has caused erosion of the culvert outlet. Based on field observation, it could not be determined whether episodic increases from culvert plugging during large winter storm events and runoff, or systemic increases in watershed hydrology, have triggered the recent bed erosion and valley wall instability. The total eroded volume from Silver Creek‘s streambanks was estimated at 1,190 cubic yards. 2.8.2 Depositional Reaches A major area of deposition occurs in Silver Creek as it enters the Puyallup River Valley. A recent restoration project and culvert replacement project through 12th Avenue SE experienced significant sediment deposition in recent years. The project is located near the slope break between the steeper glacial terrace channel slope and that of the Puyallup River Valley. The zone of deposition is consistent with what was observed at Clarks, Rody, and Woodland Creeks, and appeared to be dominated by sand and silt. Deposition occurs in this reach of channel all the way to its confluence with Meeker Ditch. A smaller area of deposition was observed immediately of the 23rd Avenue SE culvert caused by the large area of valley wall erosion. This depositional area is of a significant head cut running over a relatively resistant clay deposit. 2.8.3 General Geomorphic Condition and Observations Silver Creek is very similar to most of its adjacent tributaries that run down the glacial terrace adjacent to the Puyallup River Valley. It also shows significant incision and lateral erosion along segments of channel that have delivered substantial volumes of sand- and silt-sized sediment to a depositional reach between the Puyallup River Valley toe and its confluence with Meeker Ditch. Upstream sediment sources will likely continue to deliver sand, silt, and gravel to lower Silver Creek and Meeker Ditch. 2.9 Meeker Ditch Meeker Ditch was viewed at 16th Street SE, 14th Street SE, and at its confluence with Silver Creek. ---PAGE BREAK--- Field Investigations 9 DRAFT for review purposes only. Use of contents on this sheet is subject to the limitations specified at the end of this document. FieldInvestigationsMemo mmvz (3).docx 2.9.1 Sediment Point Sources and Instability Meeker Ditch is a confined channel running within the Puyallup River Valley. No large point sources of sediment were observed. 2.9.2 Depositional Reaches A small delta of deposited gravel and larger sediments was observed at the mouth of Silver Creek. Otherwise, no large depositional reaches were observed. The channel geometry and slope appear capable of transporting sediment that is delivered to the channel. 2.9.3 General Geomorphic Condition and Observations Meeker Ditch is relatively stable and appears able to transport existing sediment loads. Silver Creek is the primary tributary to Meeker Ditch and is likely delivering upstream sand and silt from upstream source areas. A small segment of silt and sand deposition occurred at the confluence with Silver Creek. 3. Sediment Sampling and Analysis Brown and Caldwell used existing data to tentatively identify cross-section locations for sediment sampling and hydraulic analyses. These tentative cross-section locations were then adjusted based on the field reconnaissance described above. Each cross-section was located using GPS and flagged in the field. Attachment B contains a map and coordinates for the each cross-section. The project budget allowed for sediment sampling at 20 cross-sections, which are shown on Figure 2 and summarized below: • 10 sampling locations in the Clarks Creek mainstem • 3 sampling locations in Rody Creek • 1 sampling location in Diru Creek • 1 sampling location in Woodland Creek • 3 sampling locations in Silver Creek • 1 each on 2 unnamed tributaries east of Silver Creek 3.1 Methodology Five surficial sediment subsamples were taken at equally spaced intervals along each cross-section. The subsamples were collected using a scoop where stream conditions allowed easy access. A Van Veen sampler was used where the benthic layer was not reachable or flow rates were too high. The five subsamples were combined in a stainless-steel mixing bowl to form one composite sample for laboratory analysis. The composite sediment samples were poured into two containers: one for analysis of conventional parameters and one for particle size distribution analysis. The containers were then packed in ice and delivered to the lab at the end of each sampling day. The sediment samples were analyzed for total organic carbon (TOC), total Kjeldahl nitrogen (TKN), nitrate and nitrite nitrogen, total phosphorus (TP), biochemical oxygen demand (BOD), fecal coliform bacteria, total solids (TS), and grain size distribution (GSD). ---PAGE BREAK--- Field Investigations 10 DRAFT for review purposes only. Use of contents on this sheet is subject to the limitations specified at the end of this document. FieldInvestigationsMemo mmvz (3).docx All samples were collected between July 27, 2011, and August 9, 2011. The samples were collected shortly after the City of Puyallup and Pierce County had completed their annual cutting of elodea in Clarks Creek of sampling site Clarks-04. ---PAGE BREAK--- Field Investigations 11 DRAFT for review purposes only. Use of contents on this sheet is subject to the limitations specified at the end of this document. FieldInvestigationsMemo mmvz (3).docx Figure 2. Sediment sampling sites ---PAGE BREAK--- Field Investigations 12 DRAFT for review purposes only. Use of contents on this sheet is subject to the limitations specified at the end of this document. FieldInvestigationsMemo mmvz (3).docx 3.2 Data Quality Review Data quality was assessed in terms of representativeness, comparability, precision, accuracy, and completeness, in accordance with the QAPP. Representativeness. The sampling sites were selected based on previous data collection, field reconnaissance, and recommendations from the project geomorphologist. The objective of proper site selection was to capture the different conditions observed along Clarks Creek, including flow rates and benthic sediment composition, as well as capturing potential sediment point sources from the Clarks Creek main tributaries. Care was taken to follow the laboratory recommendations when collecting and transporting the field samples for laboratory analyses. In addition, all of the proper documentation was filled out sample labels, field notebooks, and chain of custody) before submitting them to the lab. The case narratives from the sediment analyses report stated that some of the samples contained woody or other organic matter, which may have broken down during the sieving process. The presence of organic debris is representative of Clarks Creek and its tributaries. Comparability. Sample comparability was ensured by following U.S. Environmental Protection Agency (EPA)-recommended sampling methods and analytical procedures, as described in the previous sections. Precision. Duplicate samples were collected at four sites by filling two additional containers with the same homogenized bulk sample used for the field sample. The duplicate samples were assigned fictional sample locations and submitted to the lab for the same laboratory analyses: TOC, TKN, nitrate and nitrite, TP, BOD, fecal coliform, TS, and particle size distribution. Precision was assessed by calculating the relative percent difference (RPD) between the duplicate samples. RPDs less than 40 percent are generally considered acceptable for field duplicates of sediment samples (EPA, 2001). The RPDs were consistently below the established criteria, with the exception of those presented in Table 1. The elevated RPDs are probably due to the heterogeneity of the sediment material rather than imprecision in the laboratory analyses. Table 1. RPDs >40 Percent Site ID Total phosphorus Total Kjeldahl nitrogen Fecal coliform Clarks-07 52.5% 52.5% Rody-03 56.5% 84.0% Accuracy. The accuracy of the laboratory data was determined by analyzing matrix spike and blank samples. Matrix spikes and blanks were analyzed for each analytical batch. The matrix spiked samples were all within the 75–125 percent recovery range prescribed in the QAPP, with the exception of BOD in two of the five analytical batches. Due to the incubation time required for BOD analysis, no corrective measures could be taken. The implications on the laboratory results were documented in the data analysis spreadsheet. Blank samples are used as laboratory control samples (LCS) and to confirm standard reference material (SRM) reporting limits. For the LCS, a spike is introduced into blank material, as opposed to sediment matrix, and analyzed. The LCS should show recoveries within 75–125 percent. The SRM is ---PAGE BREAK--- Field Investigations 13 DRAFT for review purposes only. Use of contents on this sheet is subject to the limitations specified at the end of this document. FieldInvestigationsMemo mmvz (3).docx performed on blank samples with no spike. SRM’s method detection limit (MDL) depends on the type of laboratory analysis. For a table of SRM and the control limits, please refer to the project QAPP. The SRM samples are required to be within an acceptance range from the MDL to confirm that no contamination is present in the sample. When the percent recovery of the sample (matrix) spikes is outside of the acceptance range, LCS and SRM are evaluated to determine if it is due to laboratory error or lack of sample homogeneity. LCS associated with BOD analysis were lower than the acceptance range on two batches. However, because of the incubation period, the holding time had expired by the time results were read and no corrective action could be taken. The BOD concentration for the sampling sites in Silver and Rody Creeks could potentially be twice as high as the reported value, and for the sampling sites in Diru Creek and the unnamed tributaries approximately 30 percent higher than the reported value. No other anomalies were observed. SRM recoveries for TP were higher than the reporting limit in 3 out of the 5 analytical batches. Because this concentration is significantly below the concentrations measured in all actual samples, it was considered acceptable. No other anomalies were reported. Completeness. In general, all of the sediment analysis results were deemed usable for the Clarks Creek sediment reduction management plan. The accuracy discrepancies described above will be annotated in the results spreadsheet for consideration when future samples are analyzed and compared. ---PAGE BREAK--- Field Investigations 14 DRAFT for review purposes only. Use of contents on this sheet is subject to the limitations specified at the end of this document. FieldInvestigationsMemo mmvz (3).docx 3.3 Sediment Analysis Section 3.3.1 summarizes the results of the grain size analyses. Section 3.3.2 summarizes the results for chemical analyses. Attachment C contains all of the sediment data. 3.3.1 Grain Size Distribution Figure 3 shows the sediment grain size distribution at each cross-section. The following paragraphs describe the apparent patterns. Note that the item numbers go from upstream to sampling sites in Clarks Creek, including where the tributaries enter it. ---PAGE BREAK--- Field Investigations 15 DRAFT for review purposes only. Use of contents on this sheet is subject to the limitations specified at the end of this document. FieldInvestigationsMemo mmvz (3).docx Figure 3. place holder for stick diagram ---PAGE BREAK--- 16 DRAFT for review purposes only. Use of contents on this sheet is subject to the limitations specified at the end of this document. FieldInvestigationsMemo mmvz (3).docx Clarks Creek Mainstem Sediment samples collected at upstream sites generally had higher percentages of gravel and coarse sand than the sites. • Clarks-03, located upstream of the WDFW masonry dam, had a higher concentration of fine sand than the upstream sites. The geomorphologic report identified this site as a depositions area. On the other hand, Clarks-04, located of the dam, shows an increase in gravel, which is consistent with the field observations of this reach having more stable conditions. • Samples collected at Clarks-05 near the Clarks Creek Park south parking lot showed an increase in silt and clay content. This can be attributed to the changes in the channel hydraulic characteristics. Upstream of this site, Clarks Creek widens and the slope decreases as it enters the Puyallup River Valley. In addition, elodea growth starts approximately 200 feet upstream of this site. The elodea slows down the flow and raises the water depth, allowing fine sediment to settle. • of Clarks-05 is the confluence of Meeker Ditch with Clarks Creek. Silver Creek and two unnamed tributaries discharge into Meeker Ditch, as described below: o Silver Creek: Three sites were sampled in Silver Creek. The composition of the channel bed was predominantly gravel and sand. In contrast to Rody Creek, Silver Creek contained a relatively high percentage of fine sand. It remained fairly constant along the sampled reaches. Silver Creek discharges to Meeker Ditch. o West (unnamed tributary): Only one site was sampled in this tributary. The sample showed a gravel and sand composition with a relatively low percentage of fine sand. This tributary stream discharges into Meeker Ditch. o East (unnamed tributary): Only one site was sampled in this tributary. The sample showed a very uniformly distributed composition of gravel, coarse sand, fine sand, and a small percentage of silt. This tributary stream discharges into Meeker Ditch. • The sites of the confluence with Meeker Ditch show little to no influence from Silver Creek and the two unmanned tributaries. According to the sediment source estimates, Silver Creek can potentially contribute an important volume of sediment to Clarks Creek, but recent restoration projects and culvert replacement have captured a large portion of the load, preventing it from reaching Meeker Ditch and Clarks Creek. • Woodland and Diru Creeks appear to have little to no influence on Clarks Creek streambed composition. This is in accordance with the observation from the project geomorphologist that found that Diru Creek has a stable channel and while Woodland Creek showed channel instability, most of its sediment load is deposited in the canary grass wetland before entering Clarks Creek. o Woodland Creek: One site was sampled in Woodland Creek. The sample showed a composition of gravel and sand, which also included a relatively small percentage of fine sand. o Diru Creek: One site was sampled in Diru Creek. The sample was primarily gravel and sand. • Rody Creek enters the Clarks Creel mainstem upstream of Clarks-09. ---PAGE BREAK--- Field Investigations 17 DRAFT for review purposes only. Use of contents on this sheet is subject to the limitations specified at the end of this document. FieldInvestigationsMemo mmvz (3).docx o Rody Creek: Three sites were sampled in Rody Creek. The composition of the channel bed was predominantly gravel and sand. It remained fairly constant along the sampled reaches. • Finally, the data showed a break in the pattern as we reach the most site in Clarks Creek (Clarks-10). The bed load composition changes from primarily fine sand to gravel. This can be attributed to the load contributed from Rody Creek, which showed a primarily gravel streambed composition. The sampling results confirm the geomorphologist’s observations that Rody Creek is a major source of sediment in Clarks Creek lower reaches and that the majority of the sediment contributed consists of small gravel, sands, and silt. 3.3.2 Conventional Parameters The samples were analyzed for TOC, TKN, nitrate and nitrite, TP, BOD, fecal coliform bacteria, and TS. Table 2 summarizes the analytical results. Table 2. Conventional Parameters Laboratory Results Site ID % TS Total fines a TP (mg/kg) TKN NO3+NO2 BOD (mg/kg) % TOC Fecal coliform (CFU/g) Clarks Creek Clarks-01 88.5 5.4 465 368 9 286 1.58 37 Clarks-02 83.4 2.4 203 80.8 0.11 0 0.454 52 Clarks-03 80.9 2.5 142 205 0.33 0 0.464 0 Clarks-04 84 2.2 209 146 0 169 0.684 2 Clarks-05 40.4 33 119 2,380 0 1,320 7.18 0 Clarks-06 46.3 17.8 1,090 1,860 0 1,710 3.19 129 Clarks-07 46.5 16.3 440 1,600 0 1,820 2.44 170 Clarks-08 39.7 41.2 1,740 2,540 0 3,070 3.49 49 Clarks-09 48.4 35.4 766 1,970 0 1,660 2.35 0 Clarks-10 71.1 9.1 660 591 0 550 1.06 28 Rody Creek Rody-01 84.2 0.3 168 96.6 0.98 0 0.481 527 Rody-02 79.2 0.2 197 260 0.57 0 0.607 0 Rody-03 83.5 0.1 120 193 0.47 0 0.287 0 Diru Creek Diru-01 83.6 1.1 161 157 0.48 0 0.259 0 Woodland Creek Wood-01 94.5 2.4 81.7 573 2.86 173 1.12 27 Silver Creek ---PAGE BREAK--- Field Investigations 18 DRAFT for review purposes only. Use of contents on this sheet is subject to the limitations specified at the end of this document. FieldInvestigationsMemo mmvz (3).docx Table 2. Conventional Parameters Laboratory Results Site ID % TS Total fines a TP (mg/kg) TKN NO3+NO2 BOD (mg/kg) % TOC Fecal coliform (CFU/g) Silver-01 78.3 1.7 321 370 0.24 229 2.35 27 Silver-02 86.7 2.2 205 355 0 337 0.999 192 Silver-03 81.5 0.5 142 93.7 0.19 163 0.667 28 Other tributaries West-01 82.3 4 3.93 211 0 145 0.583 92 East-01 64.5 29.7 277 1,970 0 340 3.97 36 a. Total fines is the sum of the percentage of silt and clay particle size. In general, concentrations of TP, nitrogen, BOD, and TOC appeared to be higher in samples with higher percentages of fine-grained material. Fecal coliform bacteria concentrations did not appear to increase with percent fines. 4. Summary The following bullets summarize the key findings from the summer 2011 geomorphology reconnaissance and sediment sampling: • Field reconnaissance found evidence of substantial channel erosion on upper Clarks, Silver, Rody, and Woodland Creeks. • Potential causes for the observed channel erosion include forest removal, creation of impervious surfaces, Puyallup River channel straightening, and large winter storms and floods. • Channel erosion on upper Clarks and Rody Creeks appears to contribute substantial sediment to lower Clarks Creek. • The masonry dam on Clarks Creek near the Puyallup Trout Hatchery appears to trap coarse sediment but not sand and smaller material. • Much of the sediment from channel erosion on upper Silver and Woodland Creeks appears to be trapped before reaching Clarks Creek. • Sediment samples with higher concentrations of fine sediment (silt and clay) generally had higher concentrations of TP, total nitrogen, BOD, and TOC. The data did not show an apparent relationship between fecal coliform and grain size distribution. 5. Limitations This memorandum is a working document. The information contained in this memorandum will be used to help identify and evaluate sediment control measures. The information presented may be superseded by subsequent evaluations and reports. The eroded sediment volumes were estimated based on field observations and measurements made during the summer of 2011. Little information was available regarding channel geometry and hydraulic characteristics under natural conditions. The sediment volume estimates were developed ---PAGE BREAK--- Field Investigations 19 DRAFT for review purposes only. Use of contents on this sheet is subject to the limitations specified at the end of this document. FieldInvestigationsMemo mmvz (3).docx to support identification and development of sediment control measures. The sediment estimates may or may not be appropriate for other uses. The observations and measurements presented in this memorandum are based on one round of field reconnaissance and sediment sampling performed during the summer of 2011. They are only representative of the conditions at the time of sampling. 6. References Clear/Clarks Creek Basin Plan Phase 2: Water Quality, Habitat and Flooding Problem Analysis. Appendix E. Pierce County. Clarks Creek Watershed Pollution Reduction Project Submittal Report. 2005. URS Group Inc. and Brown and Caldwell. Prepared for the City of Puyallup Engineering Department. Historical Platte Map. Puyallup Indian Reservation map files. Savoca, M.E., Welch, W.B., Johnson, K.H., Lane, R.C., Clothier, B.G., and Fusser, E.T., 2010, Hydrogeologic framework, groundwater movement, and water budget in Chambers-Clover Creek Watershed and vicinity, Pierce County, Washington: U.S. Geological Survey Scientific Investigations Report 2010-5055, 46 p. ---PAGE BREAK--- Attachment A – Sediment Source Volumes During the field investigations, visual estimates of eroded stream bed and bank materials were noted. Stream bed erosion was estimated based on visual indicators of depth of incision and channel width. Depth of incision was estimated from grade controls including trail and road crossings, roots and logs spanning the channel. Nearby intact channel conditions were visually extrapolated to eroded sections to estimate depth of incision and channel width. Bank erosion was visually estimated by comparing eroded banks to nearby intact banks. An estimate of the eroded cross section height, width (lateral migration) and whether the section was generally rectangular or triangular in shape were noted. of individual eroded segments were estimated using either GPS, hip chain, pacing or visual estimates. Erosion volumes of incremental eroded segments were estimated from cross sectional area multiplied by length. The following tables provide a summary of the estimated dimensions and order of magnitude volume of eroded material. ---PAGE BREAK--- Clarks Creek sediment source estimates ‐ to upstream d/s GPS u/s GPS L (ft) Ht (ft) Base (ft) shape Volume c.y. factor feature 395 396 125 125 1 8 7 5 1 0.5 bed bank 32.4 92.6 396 30 8 10 0.5 bank 44.4 397 30 4 6 0.5 bank 13.3 398 399 35 30 1.5 4 10 6 1 0.5 bed bank 19.4 13.3 400 50 50 2 10 8 8 1 0.5 bed bank 29.6 74.1 401 402 105 6 10 0.5 bank 116.7 402 403 60 30 4 30 12 15 1 0.5 bed bank 106.7 250 403 404 40 20 12 0.5 bank 177.8 404 405 45 45 6 40 15 30 1 0.5 bed bank 150 1000 405 406 0.5 * 404‐405 575 406 407 0.8 * 404‐405 920 407 408 105 20 15 bank 0 408 409 75 75 75 4 12 12 10 10 10 1 0.5 0.5 bed bank bank 111.1 166.7 166.7 409 410 75 75 75 5 20 20 10 10 10 1 0.5 0.5 bed bank bank 138.9 277.8 277.8 410 411 70 12 10 1 bed 311.1 411 412 0.5*L 0.5*L 50 50 5 10 6 12 1 1 bed bed 55.6 222.2 Total 5340 ---PAGE BREAK--- Clarks Creek Tributary sediment source estimates ‐ upstream to u/s hipchain d/s hipchain L (ft) Ht (ft) Base (ft) shape Volume c.y. factor feature 50 50 20 5 10 10 1 1 bank x2 bed 370.4 92.6 27 27 30 5 15 10 1 1 bank x2 bed 450 50 90 40 40 40 5 15 15 1 1 bank x2 bed 888.9 111.1 90 158 68 50 12 3 10 8 1 1 bank x2 bed 302.2 44.4 158 202 44 44 20 4 15 10 1 1 bank x2 bed 488.9 65.2 210 268 58 58 15 3 15 8 0.5 1 bank bed 241.7 51.6 302 326 24 15 10 0.5 bank 66.7 440 470 30 20 15 0.5 bank 166.7 688 = gps 413 Total 3390 ---PAGE BREAK--- Diru Creek sediment source estimates ‐ to upstream d/s GPS u/s GPS L (ft) Ht (ft) Base (ft) shape Volume c.y. factor feature 424 35 35 12 3 10 10 0.5 1 bank bed 77.8 38.9 425 431 433 435 20 8 10 0.5 bank 29.6 15 8 6 0.5 bank 13.3 25 12 12 0.5 bank 66.7 20 50 6 6 0.5 bank 13.3 40 10 10 0.5 bank 74.1 50 50 15 8 10 10 0.5 bank 138.9 0.5 bank 74.1 Total 530 ---PAGE BREAK--- Rody Creek sediment source estimates ‐ upstream to u/s GPS d/s GPS L (ft) Ht (ft) Base (ft) shape Volume c.y. factor feature 448 100 2 5 1 bed 37 451 30 30 100 20 6 4.5 10 6 12 0.5 0.5 1 bank bank bed 111.1 20 200 452 gen'l 3 12 1 bed 0 453 40 100 50 5 2 5 5 0.5 1 bank bed 18.5 37 454 30 30 50 2 3 8 12 5 6 1 1 0.5 bed bed bank 26.7 16.7 44.4 457 30 15 10 0.5 bank 83.3 457 200 5 30 1 sed wedge 1111.1 466 40 5 10 1 landslide 74.1 467 40 8 8 0.5 bank 47.4 469 30 4.5 25 1 flood deposits 125 d/s of Pioneer Ave dredging 300 4 12 1 dredge 533.3 Total 2490 ---PAGE BREAK--- Woodland Creek sediment source estimates ‐ upstream to d/s hip chain u/s hip chain L (ft) Ht (ft) Base (ft) shape Volume c.y. factor feature 84th Ave 0 191 250 326 372 444 496 100 250 290 372 444 600 524 100 30 59 40 46 50 72 156 28 4 6 7 10 12 8 10 30 8 20 8 12 12 12 15 15 1 1 1 1 1 1 1 0.5 bed bed bed bed bed bed bed bank 118.5 133.3 122.4 177.8 245.3 256 866.7 233.3 Other areas with 'relatively minor' erosion ‐ midway along WSU reach Total 2150 ---PAGE BREAK--- Silver Creek sediment source estimates ‐ upstream to d/s GPS u/s GPS L (ft) Ht (ft) Base (ft) shape Volume c.y. factor feature at u/s road Xing 488 489 490 491 u/s of 15th Ave SW 485 d/s of 15th Ave 496 488 489 490 60 50 70 35 40 135 50 30 30 20 15 10 7.5 5 3 5 6 6 20 10 15 10.5 6 10 5 5 12 1 1 1 1 1 1 0.5 1 1 bed bank retreat bed bed bed bed bank bank retreat bed 890 280 390 100 44 150 23 33 80 Total 1990 ---PAGE BREAK--- ---PAGE BREAK--- Attachment B – Site Maps ---PAGE BREAK--- ---PAGE BREAK--- 419 388 XS418 389 DAM 389 417 XS416 390 389-391 IMPOUNDED DELTA 391 OFCHANNELINCISION 393 392 XS414 XS415 391-394 CHANNEL XS413-218'UpstreaminTributary DEPOSITION 395-402 CHANNELINCISIONWITH BANKEROSION10'HIGH 395 394 402-408 SEVERECHANNEL INCISIONANDBANK EROSION20'-40'HIGH 403 400 401 397 396 XS399 398 408-411 CHANNELINCISION WITHBANK EROSION20'HIGH XS411-AtRootLine 409 410 408 405 404 407 406 411-412 402 TRIBUTARY LEGEND: 96thST.E 412 CHANNELINCISIONWITHBANK EROSION5'-10'HIGH. UPSTREAMOF412-ANALOG CONDITIONS WAYPOINTS INCISION DEPOSITION PLANVIEW 1OF 5 PlanViewofClarks CreekWaypoints ---PAGE BREAK--- CANYONRD.E 62ndAVE.E AGGRADATION 472 CROSSVALLEY3.5' HIGHRIPRAPWEIR 470-472 AGGRADATION 472 471 XS473 474 470 465 AGGRADATION XS468 466 469 467 465 466-467 RIGHTBANKEROSION ANDLANDSLIDE TRIBUTARIES 460 464 463 461 462 459-464 SEDIMENTWEDGE FROMCULVERTINLET TRASHRACKTOWER 459 458 RODYCREEK 451-454 MODERATEINCISION 450 457 XS456 455 454 XS453 452 451 MODERATEINCISION 449 448 447 XS446 LEGEND: WAYPOINTS AGGRADATION 445 444 INCISION BANKEROSION PLANVIEW 2OF 5 PlanViewofRody CreekWaypoints ---PAGE BREAK--- FLOW WOODLANDAVE. XS421 420 LEFTBANK EROSION XS423 424 RIGHTBANKEROSION 425 426 427 428 429 DIRVCREEK XS430 431 432 433 434 424-438 OVERALLGENERALLY STABLEWITHSLIGHT TOMODERATE OCCURRENCESOF LANDSLIDES,BANK EROSION,AND CHANNELINCISION 439 TRAILCROSSING, CULVERTPERCHED APPROX.6' 438 435 436 XS437 439 XS440 440-442 PERIODICOCCURRENCE INCISIONCHECKEDBY TREEROOTS 441 442 443 LEGEND: WAYPOINTS BANKEROSION PLANVIEW 3OF 5 PlanViewofDiru CreekWaypoints ---PAGE BREAK--- WOODLANDAVE. FRUITLANDAVE. 482 481 WOODLANDCREEK CHANNELINCISED APPROX.4'-6'DEEP 479 480 475 BANKEROSIONAND BEDINCISION CULVERTOUTLET PERCHEDAPPROX.3.5' SLIGHTINCISION, SOMEBEDAND BANKARMORING 476 XS477 478 LEGEND: WAYPOINTS INCISION BANKEROSION PLANVIEW PlanViewof 4OF 5 WoodlandCreek Waypoints ---PAGE BREAK--- 14thST.SW 10thAVE.SW XS487 AGGRADATION 486 HEADCUT 15thAVE.SW 483 484 XS485 483-485 SLIGHTINCISION MODERATELATERAL MIGRATIONATBENDS 19thAVE.SW SILVERCREEK 489-491 MODERATEINCISION 493 XS494 489-497 SEVEREINCISIONAND BANKMIGRATION 496 489 495 497 490 492 491 23rdAVE.SW 492-494 AGGRADATION LEGEND: WAYPOINTS AGGRADATION INCISION HEADCUT PLANVIEW 5OF 5 PlanViewofSilver CreekWaypoints ---PAGE BREAK--- ---PAGE BREAK--- Attachment C – Sediment Data Analysis ---PAGE BREAK--- ---PAGE BREAK--- General notes: The Site ID was determined by the creek's name and its location as related to most upstream and most The most upstream location is xxxx-01 and as the number increases, we move Site ID Description/Comments Clarks01 – This site is located within the Clarks Creek Park. – Accessed by foot through the park's trail system off of 23rd Ave. – The site is of headcuts that are approximately 14 feet high. – No running water at the time of sampling. . Clarks02 – This site is located within the Clarks Creek Park. – Accessed by foot through the park's trail system off of 23rd Ave. – The site is of headcuts that are approximately 14 feet high. – No running water at the time of sampling. . Clarks03 – This site is located upstream of the Maplewood Springs. – Accessed from the State's hatchery road system. Clarks04 – This site is located of the City of Puyallup Maplewood Springs. – Accessed from the State's hatchery road system. Clarks05 – This site is located by the Clarks Creek Park south entrance parking lot. – Easily accessible. – This site was part of Brown and Caldwell's 2009 DO study. Clarks06 – This site is located by the Decoursey Park entrance parking lot. – Easily accessible. – This site was part of this year's Elodea Pulling pilot project. Clarks07 – This site is located at the intersection of 22nd and Pioneer. Under the bridge. – Easily accessible from the street. Clarks08 – This site is located in a residential area. Off of Tacoma road. – This site was part of Brown and Caldwell's 2009 DO study. – It was difficult to obtain the sediment samples from the bridge, so we waded across - with high water levels. Clarks09 – This site is located of the Clarks Creek Puyallup Tribe hatchery intake and screens. – Accessed from the hatchery's property. Clarks10 – This site is located near the convergence of Clarks Creek into the Puyallup River. – Accessed through a residence. Rody01 – This site is located the most upstream from the 72nd culvert structure. – Accessed by foot from 72nd. Rody02 – This site is located the directly upstream from the 72nd culvert structure. – Accessed by foot from 72nd. Rody03 – This site is located directly upstream of the 72nd culvert structure. – Accessed by foot from 72nd. Diru01 – This site is located close to the confluence of Diru Creek into Clarks Creek. – Accessed by foot from Pioneer Rd. Wood01 – This site is south of the wetland. – Easily accessible from Fruitland St. Silver-01 – This site is located north of 23rd. – Accessed by foot from 23rd. – This site is within a residential area. – Samples were collected of headcuts that were approximately 20 feet high. Silver-02 – This site is located north of 23rd. from Silver-01. – Accessed by foot from 23rd. – This site is within a residential area. – Samples were collected at a braid in the stream. The entire cross section was used for the composite sample. Silver-03 – This site is located south of 15th. – Accessed by foot through a trail system. – This reach of Silver Creek was very urbanized and it resemble more a drainage ditch. West-01 – This site is located east of Silver Creek and south of 15th. – Accessed through a residence. East-01 – This site is located east of West-01 and south of 15th. – Accessed from a gas station parking lot. Un-named Tributaries Clarks Creek Rody Creek Diru Creek Woodland Creek Silver Creek ---PAGE BREAK--- LENGEND Gravel Sand Silt Clay Puyallup Tribe Hatchery Clarks-09 Clarks-10 7th Ave SW CLARKS CREEK DIRU CREEK WOODLAND CREEK RODY CREEK Rody-03 Rody-02 Rody-01 Diru-01 Wood-01 72nd Culvert Structure Clarks-07 Clarks-08 CLARKS CREEK MEEKER DITCH SILVER CREEK WEST (UNNAMED TRIB) EAST (UNNAMED TRIB) 15th Ave SW Maplewood Springs West-01 East-01 Silver-03 Clarks-04 Clarks-05 Clarks-06 Silver-02 Silver-01 CLARKS CREEK Clarks-01 Clarks-02 Clarks-03 ---PAGE BREAK--- General Notes: Results GRAIN SIZE (COMPOSITE SAMPLE) Coarse Sand Very Coarse Silt Coarse Silt Medium Silt Very fine Silt Clay Site ID 32" 21.5" 1.51" 1"3/4 3/41/2" 1/23/8" 3/8"4750 47502000 2000850 850425 425250 250150 15075 7532 3222 2213 139 97 73.2 <3.2 Clarks01 0 0 4.4 4.7 23.3 6.7 11.2 8.7 4.9 9.4 11.9 6 3.3 0 0.4 0.7 0.7 1.1 0.9 1.6 Clarks02 0 0 9.5 23.2 20.7 8.5 11.5 7.1 5.5 4.8 3.6 2 1.1 1 0.3 0.1 0.1 0.2 0.3 0.4 Clarks03 0 0 0 0 5.6 9.2 16.9 17.7 14.9 10.7 10.6 6.8 5 0.6 0 0.2 0.4 0.2 0.7 0.4 Clarks04 0 0 0 3.8 12.7 10.6 20.9 16.5 10.4 11.3 7.2 2.6 1.7 0.1 0.5 0 0.3 0.5 0.5 0.3 Clarks05 0 0 0 0 6.8 1.1 0.4 1.2 3.9 7.1 10.2 17.2 19.1 12 3.3 4.6 5.2 2.6 3.3 2 Clarks06 0 0 0 0.5 9.7 3.2 11.5 5.6 3.3 3.6 8.1 16.3 20.4 5.7 2.6 2.6 3 0.9 1.3 1.7 Clarks07 0 0 0 0 15.3 5 10.8 7.9 5.1 3.5 3.4 9.4 23.2 7.2 2.6 2.9 0.7 0.7 1.1 1.1 Clarks08 0 0 0 0 0 0 0.6 0.4 1.5 3.4 7.1 17.3 28.4 17 5.3 5.3 3 2.3 3 5.3 Clarks09 0 0 0 0 0 0 0.1 0.9 2.9 5.1 6.8 17.3 31.6 10.9 5.6 4.2 2.1 1.4 7.7 3.5 Clarks10 0 0 0 4.6 18.1 15 18.3 6.3 3.5 4.6 4.7 5.6 10.2 4.9 0.5 0.7 1.6 0.5 0.2 0.7 Duplicates Samples ClarksA (Clarks07) 0 0 0 5.9 12.2 3.3 7.4 5.8 5 3.3 3.5 9.9 26.4 6.3 3.2 1.4 3.2 0.5 1.4 1.4 ClarksB (Clarks04) 0 0 0 0 12.4 7.9 23.9 19.6 10.3 12.2 8 2.8 1.7 0.5 0 0 0.2 0 0 0.5 CONVENTIONALS (COMPOSITE SAMPLE) Total Solids Nitrate + Nitrite (NO3+NO2) Total Phosphorus Total Kjeldahl Nitrogen Biological Oxygen Demand Total Organic Carbon Fecal Coliforms Site ID % mg-N/kg mg/kg mg-N/kg mg/kg % CFU/g Clarks01 88.5 9 465 368 286 1.58 37 Clarks02 83.4 0.11 203 80.8 11.1 U 0.454 52 Clarks03 80.9 0.33 142 205 69.3 U 0.464 2 U Clarks04 84 0.12 U 209 146 169 0.684 2 Clarks05 40.4 2.36 U 119 2380 1320 7.18 5 U Clarks06 46.3 1.06 U 1090 1860 1710 3.19 129 Clarks07 46.5 1.05 U 440 1600 1820 2.44 170 Clarks08 39.7 1.24 U 1740 2540 3070 3.49 49 Clarks09 48.4 1 U 766 1970 1660 2.35 41 U Clarks10 71.1 0.67 U 660 591 550 1.06 28 Duplicates Samples ClarksA (Clarks07) 44 1.13 U 926 1780 1910 1.99 358 ClarksB (Clarks04) 83 0.12 U 283 176 100 0.667 2 U GRAIN SIZE (SUBARMOR LAYER) Coarse Sand Very Coarse Silt Silt and Clay Site ID 53" 32" 21.5" 1.51" 1"3/4 3/41/2" 1/23/8" 3/8"4750 47502000 2000850 850425 425250 250150 15075 <75 Clarks01 0 0 7.7 29 18.5 16.2 6.1 7.1 4.3 2.7 2.8 2.2 1 0.6 2 Clarks02 0 0 2.7 21.1 14.5 18.5 7.5 13.5 10.4 5.7 3.7 1.6 0.3 0.1 0.4 Clarks03 0 0 0 5.3 9.6 21.9 10.1 21.4 15.5 8.8 5.3 1.6 0.3 0.1 0.1 Clarks04 0 0 0 5.8 12.6 19.3 9.1 23.8 16.2 8 3.9 1.1 0.2 0.1 0 This sheet contains the laboratory results grouped as Grain Size Distribution (GSD) Analysis for composite samples; conventional parameters for composite samples; and the GSD Analysis for the Sub-armor samples. The Sub-armor layer GSD will not be analyzed as part of this task. It will used to in Task 4. When a appears next to a result, it means that the concentration was too low to be detected by the analytical method used. That just indicates that the concentration present was very small. Coarse Gravel Gravel Medium Sand Fine Sand Coarse Gravel Gravel Medium Sand Fine Sand Fine Silt ---PAGE BREAK--- GRAPHICAL REPRESENTATION OF THE GRAIN SIZE DISTRIBUTION FOR CLARKS CREEK From the results presented in the Clarks Creek Sites tab: Clarks01 Clarks02 Clarks03 Clarks04 Clarks05 Clarks06 Clarks07 Clarks08 Clarks09 Clarks10 Coarse Gravel 9.1 32.7 0 3.8 0 0.5 0 0 0 4.6 Gravel 41.2 40.7 31.7 44.2 8.3 24.4 31.1 0.6 0.1 51.4 Coarse Sand 8.7 7.1 17.7 16.5 1.2 5.6 7.9 0.4 0.9 6.3 Medium Sand 14.3 10.3 25.6 21.7 11 6.9 8.6 4.9 8 8.1 Fine Sand 21.2 6.7 22.4 11.5 46.5 44.8 36 52.8 55.7 20.5 Very Coarse Silt 0 1 0.6 0.1 12 5.7 7.2 17 10.9 4.9 Coarse Silt 0.4 0.3 0 0.5 3.3 2.6 2.6 5.3 5.6 0.5 Medium Silt 0.7 0.1 0.2 0 4.6 2.6 2.9 5.3 4.2 0.7 Fine Silt 1.8 0.3 0.6 0.8 7.8 3.9 1.4 5.3 3.5 2.1 Very fine Silt 0.9 0.3 0.7 0.5 3.3 1.3 1.1 3 7.7 0.2 Clay 1.6 0.4 0.4 0.3 2 1.7 1.1 5.3 3.5 0.7 Further grouping of the grain sizes yields: Clarks01 Clarks02 Clarks03 Clarks04 Clarks05 Clarks06 Clarks07 Clarks08 Clarks09 Clarks10 Gravel 50.3 73.4 31.7 48 8.3 24.9 31.1 0.6 0.1 56 Sand 44.2 24.1 65.7 49.7 58.7 57.3 52.5 58.1 64.6 34.9 Silt 3.8 2.0 2.1 1.9 31.0 16.1 15.2 35.9 31.9 8.4 Clay 1.6 0.4 0.4 0.3 2 1.7 1.1 5.3 3.5 0.7 Clarks-02 Clarks-03 Clarks-04 Clarks-05 Clarks-06 Clarks-07 Clarks-08 Clarks-01 Clarks-05 Clarks-06 Clarks-07 Clarks-08 Clarks-09 Clarks-10 ---PAGE BREAK--- CONVETIONAL PARAMETERS RESULTS FOR CLARKS CREEK From the results presented in the Clarks Creek Sites tab: Site ID % Fines % TS TP (mg/kg) TKN NO3+NO2 Total N (mg-N/kg) BOD (mg/kg) % TOC Fecal Coliforms (CFU/g) Clarks01 5.4 88.5 465 368 9 377 286 1.58 37 Clarks02 2.4 83.4 203 80.8 0.11 81 0 0.454 52 Clarks03 2.5 80.9 142 205 0.33 205 0 0.464 0 Clarks04 2.2 84 209 146 0 146 169 0.684 2 Clarks05 33 40.4 119 2380 0 2380 1320 7.18 0 Clarks06 17.8 46.3 1090 1860 0 1860 1710 3.19 129 Clarks07 16.3 46.5 440 1600 0 1600 1820 2.44 170 Clarks08 41.2 39.7 1740 2540 0 2540 3070 3.49 49 Clarks09 35.4 48.4 766 1970 0 1970 1660 2.35 0 Clarks10 9.1 71.1 660 591 0 591 550 1.06 28 % % mg/kg mg-N/kg mg-N/kg mg-N/kg mg/kg % CFU/g 0 500 1000 1500 2000 2500 3000 3500 Total Phosphorus, Total Nitrogen, and Biological Oxygen Demand TP (mg/kg) Total N (mg-N/kg) BOD (mg/kg) ( g g) ( g g) ( g g) 0 1 2 3 4 5 6 7 8 0 20 40 60 80 100 120 140 160 180 Percent Solids, Fecal Coliforms and Total Organic Carbon % TS Fecal Coliforms (CFU/g) % TOC ---PAGE BREAK--- General Notes: Results GRAIN SIZE (COMPOSITE SAMPLE) Coarse Sand Very Coarse Silt Coarse Silt Medium Silt Very fine Silt Clay Site ID 32" 21.5" 1.51" 1"3/4 3/41/2" 1/23/8" 3/8"4750 47502000 2000850 850425 425250 250150 15075 7532 3222 2213 139 97 73.2 <3.2 Rody01 0 0 0 0 12.3 15.7 25.6 19.6 12.2 9.9 3.4 0.7 0.2 0 0 0.1 0 0 0.2 0 Rody02 0 0 5.1 10.4 21.1 10.8 20.3 13.2 7.8 6.6 3.4 0.8 0.3 0.1 0 0 0 0 0 0.1 Rody03 0 0 0 8.2 16.7 10.2 26.8 17 8.8 7.3 3.8 0.9 0.2 0.1 0 0 0 0 0 0 Duplicates RodyB (Rody02) 0 0 0 14.8 13.7 12.1 21.8 15 9.3 8 4.1 0.8 0.2 0 0 0 0 0 0 0 CONVENTIONALS (COMPOSITE SAMPLE) Total Solids Nitrate + Nitrite (NO3+NO2) Total Phosphorus Total Kjeldahl Nitrogen Biological Oxygen Demand Total Organic Carbon Fecal Coliforms Site ID % mg-N/kg mg/kg mg-N/kg mg/kg % CFU/g Rody01 84.2 0.98 168 96.6 146 U 0.481 527 Actual BOD concentrations at this site, could be twice as high as the value reported ,based on % recovery results from the lab. Rody02 79.2 0.57 197 260 158 U 0.607 2 U Actual BOD concentrations at this site, could be twice as high as the value reported ,based on % recovery results from the lab. Rody03 83.5 0.47 120 193 148 U 0.287 2 U Actual BOD concentrations at this site, could be twice as high as the value reported ,based on % recovery results from the lab. Duplicates RodyB (Rody03) 84.1 0.56 276 30.8 144 U 0.294 2 U Actual BOD concentrations at this site, could be twice as high as the value reported ,based on % recovery results from the lab. GRAIN SIZE (SUBARMOR LAYER) Coarse Sand Very Coarse Silt Silt and Clay Site ID 53" 32" 21.5" 1.51" 1"3/4 3/41/2" 1/23/8" 3/8"4750 4750 2000 2000850 850425 425250 250150 15075 <75 Rody01 0 0 0 13.1 9.1 18.5 9.9 20.9 14 5.7 3.4 2.7 1.5 0.7 0.5 Rody03 0 0 0 0 4.2 6.4 8.4 22 24.1 16.6 12.6 4.4 0.7 0.2 0.3 This sheet contains the laboratory results grouped as Grain Size Distribution (GSD) Analysis for composite samples; conventional parameters for composite samples; and the GSD Analysis for the Sub-armor samples. The Sub-armor layer GSD will not be analyzed as part of this task. It will used to in Task 4. When a appears next to a result, it means that the concentration was too low to be detected by the analytical method used. That just indicates that the concentration present was very small. Coarse Gravel Gravel Medium Sand Fine Sand Fine Silt Coarse Gravel Gravel Medium Sand Fine Sand ---PAGE BREAK--- GRAPHICAL REPRESENTATION OF THE GRAIN SIZE DISTRIBUTION FOR RODY CREEK From the results presented in the Rody Creek Sites tab: Rody01 Rody02 Rody03 Coarse Gravel 0 15.5 8.2 Gravel 53.6 52.2 53.7 Coarse Sand 19.6 13.2 17 Medium Sand 22.1 14.4 16.1 Fine Sand 4.3 4.5 4.9 Very Coarse Silt 0 0.1 0.1 Coarse Silt 0 0 0 Medium Silt 0.1 0 0 Fine Silt 0 0 0 Very fine Silt 0.2 0 0 Clay 0 0.1 0 Further grouping of the grain sizes yields: Rody01 Rody02 Rody03 Gravel 53.6 67.7 61.9 Sand 46 32.1 38 Silt 0.3 0.1 0.1 Clay 0 0.1 0 Rody-01 Rody-02 Rody-03 ---PAGE BREAK--- CONVETIONAL PARAMETERS RESULTS FOR RODY CREEK From the results presented in the Rody Creek Sites tab: Site ID % Fines % TS TP (mg/kg) TKN NO3+NO2 Total N (mg-N/kg) BOD (mg/kg) % TOC Fecal Coliforms (CFU/g) Rody01 0.3 84.2 168 96.6 0.98 98 0 0.481 527 Rody02 0.2 79.2 197 260 0.57 261 0 0.607 0 Rody03 0.1 83.5 120 193 0.47 193 0 0.287 0 % % mg/kg mg-N/kg mg-N/kg mg-N/kg mg/kg % CFU/g 200 250 300 Total Phosphorus, Total Nitrogen, and Biological Oxygen Demand 0 50 100 150 200 TP (mg/kg) Total N (mg-N/kg) BOD (mg/kg) 0 4 0.5 0.6 0.7 400 500 600 Percent Solids, Fecal Coliforms and Total Organic Carbon 0 0.1 0.2 0.3 0.4 0.5 0 100 200 300 400 % TS Fecal Coliforms (CFU/g) % TOC ---PAGE BREAK--- General Notes: Results GRAIN SIZE (COMPOSITE SAMPLE) Coarse Sand Very Coarse Silt Coarse Silt Medium Silt Very fine Silt Clay Site ID 32" 21.5" 1.51" 1"3/4 3/41/2" 1/23/8" 3/8"4750 4750 2000 2000850 850425 425250 250150 15075 7532 3222 2213 139 97 73.2 <3.2 Silver01 0 0 22.2 20.5 9.7 6.6 11.3 9.8 5 3.8 4.5 3.2 1.9 0.3 0.1 0.3 0.2 0.2 0.2 0.4 Silver02 0 0 3.1 10.1 23.8 10.6 17.8 8.3 4 4.8 6.7 5.1 3.2 0.8 0.4 0.2 0.2 0 0.4 0.2 Silver03 0 0 8.5 5.7 18.3 8.2 18 11.7 7.5 7.3 7.5 4.7 2 0 0.1 0.1 0 0.1 0.1 0.1 GRAIN SIZE (SUBARMOR LAYER) Coarse Sand Very Coarse Silt Silt and Clay Site ID 53" 32" 21.5" 1.51" 1"3/4 3/41/2" 1/23/8" 3/8"4750 4750 2000 2000850 850425 425250 250150 15075 <75 Silver01 0 0 0 32.8 17.4 13.9 7.7 9.4 6.8 4.2 3 2.3 1.2 0.5 0.6 Silver02 0 0 0 13.1 9.1 18.5 9.9 20.9 14 5.7 3.4 2.7 1.5 0.7 0.5 CONVENTIONALS (COMPOSITE SAMPLE) Total Solids Nitrate + Nitrite (NO3+NO2) Total Phosphorus Total Kjeldahl Nitrogen Biological Oxygen Demand Total Organic Carbon Fecal Coliforms Site ID % mg-N/kg mg/kg mg-N/kg mg/kg % CFU/g Silver01 78.3 0.24 321 370 229 2.35 27 Actual BOD concentrations at this site, could be twice as high as the value reported ,based on % recovery results from the lab. Silver02 86.7 0.11 U 205 355 337 0.999 192 Actual BOD concentrations at this site, could be twice as high as the value reported ,based on % recovery results from the lab. Silver03 81.5 0.19 142 93.7 163 0.667 28 Actual BOD concentrations at this site, could be twice as high as the value reported ,based on % recovery results from the lab. Fine Sand Coarse Gravel Gravel Medium Sand Fine Sand Fine Silt composite samples; conventional parameters for composite samples; and the GSD Analysis for the Sub-armor samples. The Sub-armor layer GSD will not be analyzed as part of this task. It will used to in Task 4. When a appears next to a result, it means that the concentration was too low to be detected by the analytical method used. That just indicates that the concentration present was very small. Coarse Gravel Gravel Medium Sand ---PAGE BREAK--- GRAPHICAL REPRESENTATION OF THE GRAIN SIZE DISTRIBUTION FOR SILVER CREEK From the results presented in the Silver Creek Sites tab: Silver01 Silver02 Silver03 Coarse Gravel 42.7 13.2 14.2 Gravel 27.6 52.2 44.5 Coarse Sand 9.8 8.3 11.7 Medium Sand 8.8 8.8 14.8 Fine Sand 9.6 15 14.2 Very Coarse Silt 0.3 0.8 0 Coarse Silt 0.1 0.4 0.1 Medium Silt 0.3 0.2 0.1 Fine Silt 0.4 0.2 0.1 Very fine Silt 0.2 0.4 0.1 Clay 0.4 0.2 0.1 Further grouping of the grain sizes yields: Silver01 Silver02 Silver03 Gravel 70.3 65.4 58.7 Sand 28.2 32.1 40.7 Silt 1.3 2.0 0.4 Clay 0.4 0.2 0.1 Silver-01 Silver-02 Silver-03 ---PAGE BREAK--- CONVETIONAL PARAMETERS RESULTS FOR SILVER CREEK From the results presented in the Silver Creek Sites tab: Site ID % Fines % TS TP (mg/kg) TKN NO3+NO2 Total N (mg-N/kg) BOD (mg/kg) % TOC Fecal Coliforms (CFU/g) Silver01 1.7 78.3 321 370 0.24 370 229 2.35 27 Silver02 2.2 86.7 205 355 0 355 337 0.999 192 Silver03 0.5 81.5 142 93.7 0.19 94 163 0.667 28 % % mg/kg mg-N/kg mg-N/kg mg-N/kg mg/kg % CFU/g 300 350 400 Total Phosphorus, Total Nitrogen, and Biological Oxygen Demand 0 50 100 150 200 250 300 TP (mg/kg) Total N (mg-N/kg) BOD (mg/kg) 2 2.5 200 250 Percent Solids, Fecal Coliforms and Total Organic Carbon 0 0.5 1 1.5 2 0 50 100 150 200 % TS Fecal Coliforms (CFU/g) % TOC ---PAGE BREAK--- General Notes: Results GRAIN SIZE (COMPOSITE SAMPLE) Coarse Sand Very Coarse Silt Coarse Silt Medium Silt Very fine Silt Clay Site ID 32" 21.5" 1.51" 1"3/4 3/41/2" 1/23/8" 3/8"4750 47502000 2000850 850425 425250 250150 15075 7532 3222 2213 139 97 73.2 <3.2 Diru01 0 0 7.7 14.1 16.1 12.5 20.8 14.7 6 4 2.1 0.6 0.2 0.6 0 0.1 0.1 0.1 0.1 0.1 Wood01 0 0 9.5 23.2 20.7 8.6 11.5 7.1 5.5 4.8 3.6 2 1.1 1 0.3 0.1 0.1 0.2 0.3 0.4 West01 0 0 7 5 13.1 12.2 18.4 15.6 10.1 7.3 4.8 1.3 1 0.7 0.6 0.6 0.3 0.6 0.6 0.6 East01 0 0 0 5.2 7.3 3.1 6.7 7.9 7.9 10.6 9 6.1 6.3 7.5 4.6 4.9 2.1 1.8 4.2 4.6 Duplicates DiruD (Diru01) 0 0 0 10.3 18.5 10.6 22.4 19 8.6 5.7 2.8 0.7 0.2 0.4 0 0 0.4 0.2 0.2 0.2 21.8 49.4 14.7 10 2.9 0.6 0 0.1 0.2 0.1 0.1 CONVENTIONALS (COMPOSITE SAMPLE) Total Solids Nitrate + Nitrite (NO3+NO2) Total Phosphorus Total Kjeldahl Nitrogen Biological Oxygen Demand Total Organic Carbon Fecal Coliforms Site ID % mg-N/kg mg/kg mg-N/kg mg/kg % CFU/g Diru01 83.6 0.48 161 157 120 U 0.259 2 U Actual BOD concentrations at this site, could potentially be 30% higher than reported, based on % recovery results from the lab. Wood01 94.5 2.86 81.7 573 173 1.12 27 West01 82.3 0.12 U 3.93 211 145 0.583 92 Actual BOD concentrations at this site, could potentially be 30% higher than reported, based on % recovery results from the lab. East01 64.5 0.15 U 277 1970 340 3.97 36 Actual BOD concentrations at this site, could potentially be 30% higher than reported, based on % recovery results from the lab. Duplicates DiruD (Diru01) 81.6 0.4 216 99 164 0.24 2 U This sheet contains the laboratory results grouped as Grain Size Distribution (GSD) Analysis for composite samples; conventional parameters for composite samples; and the GSD Analysis for the Sub-armor samples. The Sub-armor layer GSD will not be analyzed as part of this task. It will used to in Task 4. When a appears next to a result, it means that the concentration was too low to be detected by the analytical method used. That just indicates that the concentration present was very small. Coarse Gravel Gravel Medium Sand Fine Sand Fine Silt ---PAGE BREAK--- GRAPHICAL REPRESENTATION OF THE GRAIN SIZE DISTRIBUTION From the results presented in the rest of Clarks Creek's Tributaries Sites tab: Diru01 Wood01 West01 East01 Coarse Gravel 21.8 32.7 12 5.2 Gravel 49.4 40.8 43.7 17.1 Coarse Sand 14.7 7.1 15.6 7.9 Medium Sand 10 10.3 17.4 18.5 Fine Sand 2.9 6.7 7.1 21.4 Very Coarse Silt 0.6 1 0.7 7.5 Coarse Silt 0 0.3 0.6 4.6 Medium Silt 0.1 0.1 0.6 4.9 Fine Silt 0.2 0.3 0.9 3.9 Very fine Silt 0.1 0.3 0.6 4.2 Clay 0.1 0.4 0.6 4.6 Further grouping of the grain sizes yields: Diru01 Wood01 West01 East01 Gravel 71.2 73.5 55.7 22.3 Sand 27.6 24.1 40.1 47.8 Silt 1.0 2.0 3.4 25.1 Clay 0.1 0.4 0.6 4.6 Diru-01 Wood-01 West-01 East 01 East-01 ---PAGE BREAK--- CONVETIONAL PARAMETERS RESULTS From the results presented in the Other Tributaries Sites tab: Site ID % Fines % TS TP (mg/kg) TKN NO3+NO2 Total N (mg-N/kg) BOD (mg/kg) % TOC Fecal Coliforms (CFU/g) Diru01 1.1 83.6 161 157 0.48 157 0 0.259 0 Wood01 2.4 94.5 81.7 573 2.86 576 173 1.12 27 West01 4 82.3 3.93 211 0 211 145 0.583 92 East01 29.7 64.5 277 1970 0 1970 340 3.97 36 % % mg/kg mg-N/kg mg-N/kg mg-N/kg mg/kg % CFU/g 2000 2500 Total Phosphorus, Total Nitrogen, and Biological Oxygen Demand 0 500 1000 1500 2000 TP (mg/kg) Total N (mg-N/kg) BOD (mg/kg) 3 3.5 4 4.5 70 80 90 100 Percent Solids, Fecal Coliforms and Total Organic Carbon 0 0.5 1 1.5 2 2.5 3 3.5 0 10 20 30 40 50 60 70 80 % TS Fecal Coliforms (CFU/g) % TOC ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Appendix B: Channel Cross-Section Survey ---PAGE BREAK--- This page intentionally left blank. ---PAGE BREAK--- Stewart Ave River Rd 104th St E Canyon Rd E 96th St E 90th St E Pioneer Way Woodland Ave E Fruitland S Meridian 72nd St E 9th St SW 52nd St E 76th Ave E 84th St E 31st Ave SW Rody Creek Diru Creek Wood land Creek Cl a rk s Cre ek Silve r Cre ek Meeker Creek BC13 BC04 BC03 BC02 BC05 BC01 BC08 BC07 BC06 BC10 BC09 BC12 BC11 XS 473 XS 399 XS 446 XS 456 XS 468 XS 440 XS 437 XS 430 XS 430 XS 423 XS 422 XS 421 XS 477 XS 413 XS 414 XS 416 XS 418 XS 488 XS 485 XS 487 XS 411 XS 415 XS 494 THIS DRAWING OR FILE HAS BEEN PREPARED BY BROWN AND CALDWELL FOR ITS CLIENT AND MAY NOT BE COPIED OR USED WITHOUT WRITTEN AUTHORIZATION. DUE TO THE ALTERABLE NATURE OF ELECTRONIC MATERIALS, RECIPIENT SHOULD NOT RELY ON THIS FOR ACCURACY OR CONTENT, AND ACKNOWLEDGES AND AGREES IT HAS BEEN PROVIDED SOLELY FOR CONVENIENCE AND INFORMATIONAL PURPOSES. BROWN AND CALDWELL MAKES NO REPRESENTATIONS REGARDING SUITABILITY OR FITNESS FOR A PARTICULAR PURPOSE. 1,200 0 1,200 FT 1 inch = 2,400 feet Appendix B Appendix B Appendix B Appendix B CROSS SECTION CROSS SECTION CROSS SECTION CROSS SECTION LOCATIONS LOCATIONS LOCATIONS LOCATIONS CLARKS CREEK SEDIMENT CLARKS CREEK SEDIMENT CLARKS CREEK SEDIMENT CLARKS CREEK SEDIMENT REDUCTION ACTION PLAN REDUCTION ACTION PLAN REDUCTION ACTION PLAN REDUCTION ACTION PLAN F L E G E N D New Surveyed Cross*section Evaluation Reaches Arterial Roadway Path: P:\Puyallup Tribe\140982 Clarks Sediment Study\GIS\projects\report_figures\CCSRAP Fig Author: NFoged 1/31/2013 ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Surveyed Crosssections Appendix B STATION (FT) STATION (FT) STATION (FT) STATION (FT) NORTHING (FT) NORTHING (FT) NORTHING (FT) NORTHING (FT) EASTING (FT) EASTING (FT) EASTING (FT) EASTING (FT) ELEV (FT) ELEV (FT) ELEV (FT) ELEV (FT) DESCRIPTION (FT) DESCRIPTION (FT) DESCRIPTION (FT) DESCRIPTION (FT) POINT POINT POINT POINT STATION STATION STATION STATION 0.00 682400.[PHONE REDACTED].547 30.51 (304)GRND SHOT 1226 0 0 0 8.90 682400.[PHONE REDACTED].443 30.69 (787)SET REBAR   1220 0 8.9 8.9 14.66 682401.[PHONE REDACTED].198 27.80 (268)CREEK TOE 1225 0 14.66 14.66 17.56 682401.[PHONE REDACTED].105 28.37 (276)EDGE WATER 1224 0 17.56 17.56 19.10 682401.[PHONE REDACTED].647 27.62 (268)CREEK TOE 1223 0 19.1 19.1 20.77 682401.[PHONE REDACTED].312 29.82 (787)SET REBAR   1221 0 20.77 20.77 28.96 682400.[PHONE REDACTED].505 30.43 (304)GRND SHOT 1222 0 28.96 28.96 STATION (FT) STATION (FT) STATION (FT) STATION (FT) NORTHING (FT) NORTHING (FT) NORTHING (FT) NORTHING (FT) EASTING (FT) EASTING (FT) EASTING (FT) EASTING (FT) ELEV (FT) ELEV (FT) ELEV (FT) ELEV (FT) DESCRIPTION (FT) DESCRIPTION (FT) DESCRIPTION (FT) DESCRIPTION (FT) POINT POINT POINT POINT STATION STATION STATION STATION 0+00.00 685373.[PHONE REDACTED].160 30.73 (270)CREEK TOP 1226 0 0 0 0+07.58 685372.[PHONE REDACTED].180 26.25 (268)CREEK TOE 1220 0 8.9 8.9 0+14.56 685377.[PHONE REDACTED].071 25.51 (268)CREEK TOE 1225 0 14.66 14.66 0+27.34 685380.[PHONE REDACTED].397 29.75 (270)CREEK TOP 1224 0 17.56 17.56 0+36.26 685382.[PHONE REDACTED].153 29.44 (300)GRADE BRK 1223 0 19.1 19.1 1221 0 20.77 20.77 1222 0 28.96 28.96 BC01 (Woodland Creek) BC01 (Woodland Creek) BC01 (Woodland Creek) BC01 (Woodland Creek) BC02 (Rody Creek) BC02 (Rody Creek) BC02 (Rody Creek) BC02 (Rody Creek) 20 22 24 26 28 30 32 34 36 38 40 0 10 20 30 40 Elevation (ft) Station (ft) 20 22 24 26 28 30 32 34 36 38 40 0 1 2 3 4 5 6 Elevation (ft) Station (ft) Page 1 of18 ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Surveyed Crosssections Appendix B STATION (FT) STATION (FT) STATION (FT) STATION (FT) NORTHING (FT) NORTHING (FT) NORTHING (FT) NORTHING (FT) EASTING (FT) EASTING (FT) EASTING (FT) EASTING (FT) ELEV (FT) ELEV (FT) ELEV (FT) ELEV (FT) DESCRIPTION (FT) DESCRIPTION (FT) DESCRIPTION (FT) DESCRIPTION (FT) POINT POINT POINT POINT STATION STATION STATION STATION 0.00 675224.[PHONE REDACTED].413 213.10 (787)SET REBAR   1263 0 0 0 21.63 675218.[PHONE REDACTED].305 201.35 (304)GRND SHOT 1264 0 21.63 21.63 43.14 675213.[PHONE REDACTED].156 192.15 (300)GRADE BRK 1265 0 43.14 43.14 48.26 675212.[PHONE REDACTED].115 191.06 (270)CREEK TOP 1266 0 48.26 48.26 53.29 675210.[PHONE REDACTED].978 189.75 (268)CREEK TOE 1267 0 53.29 53.29 56.63 675209.[PHONE REDACTED].165 188.90 (256)CREEK CL 1268 0 56.63 56.63 58.35 675209.[PHONE REDACTED].843 188.97 (268)CREEK TOE 1269 0 58.35 58.35 64.46 675208.[PHONE REDACTED].870 192.69 (270)CREEK TOP 1270 0 64.46 64.46 90.37 675201.[PHONE REDACTED].886 196.90 (300)GRADE BRK 1271 0 90.37 90.37 120.57 675194.[PHONE REDACTED].125 209.81 (304)GRND SHOT 1272 1 20.57 120.57 136.64 675190.[PHONE REDACTED].685 214.29 (300)GRADE BRK 1273 1 36.64 136.64 STATION (FT) STATION (FT) STATION (FT) STATION (FT) NORTHING (FT) NORTHING (FT) NORTHING (FT) NORTHING (FT) EASTING (FT) EASTING (FT) EASTING (FT) EASTING (FT) ELEV (FT) ELEV (FT) ELEV (FT) ELEV (FT) DESCRIPTION (FT) DESCRIPTION (FT) DESCRIPTION (FT) DESCRIPTION (FT) POINT POINT POINT POINT STATION STATION STATION STATION 0.00 674353.[PHONE REDACTED].577 273.21 (787)SET REBAR   1279 0 0 0 59.31 674380.[PHONE REDACTED].253 269.55 (300)GRADE BRK 1280 0 59.31 59.31 104.69 674401.[PHONE REDACTED].560 260.07 (304)GRND SHOT 1281 1 4.69 104.69 143.69 674419.[PHONE REDACTED].205 250.57 (304)GRND SHOT 1282 1 43.69 143.69 167.50 674430.[PHONE REDACTED].355 244.35 (270)CREEK TOP 1283 1 67.5 167.5 177.13 674434.[PHONE REDACTED].934 241.73 (268)CREEK TOE 1284 1 77.13 177.13 178.92 674435.[PHONE REDACTED].523 241.65 (268)CREEK TOE 1285 1 78.92 178.92 183.70 674437.[PHONE REDACTED].764 242.83 (270)CREEK TOP 1286 1 83.7 183.7 199.99 674445.[PHONE REDACTED].241 248.70 (300)GRADE BRK 1287 1 99.99 199.99 230.75 674459.[PHONE REDACTED].563 256.37 (304)GRND SHOT 1288 2 30.75 230.75 272.83 674478.[PHONE REDACTED].946 264.79 (304)GRND SHOT 1289 2 72.83 272.83 BC03 (Woodland Creek) BC03 (Woodland Creek) BC03 (Woodland Creek) BC03 (Woodland Creek) BC04 (Woodland Creek) BC04 (Woodland Creek) BC04 (Woodland Creek) BC04 (Woodland Creek) 180 185 190 195 200 205 210 215 220 0 50 100 150 Elevation (ft) Station (ft) 240 245 250 255 260 265 270 275 0 50 100 150 200 250 300 Elevation (ft) Station (ft) Page 2 of18 ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Surveyed Crosssections Appendix B STATION (FT) STATION (FT) STATION (FT) STATION (FT) NORTHING (FT) NORTHING (FT) NORTHING (FT) NORTHING (FT) EASTING (FT) EASTING (FT) EASTING (FT) EASTING (FT) ELEV (FT) ELEV (FT) ELEV (FT) ELEV (FT) DESCRIPTION (FT) DESCRIPTION (FT) DESCRIPTION (FT) DESCRIPTION (FT) POINT POINT POINT POINT STATION STATION STATION STATION 0.00 678905.[PHONE REDACTED].370 212.08 (300)GRADE BRK 1254 0 0 0 20.46 678908.[PHONE REDACTED].583 203.79 (300)GRADE BRK 1253 0 20.46 20.46 41.57 678912.[PHONE REDACTED].431 199.16 (300)GRADE BRK 1252 0 41.57 41.57 76.82 678917.[PHONE REDACTED].251 196.06 (270)CREEK TOP 1251 0 76.82 76.82 91.03 678919.[PHONE REDACTED].288 193.78 (268)CREEK TOE 1250 0 91.03 91.03 94.25 678920.[PHONE REDACTED].475 192.25 " 1247 0 94.25 94.25 96.75 678920.[PHONE REDACTED].941 193.35 (268)CREEK TOE 1248 0 96.75 96.75 102.62 678921.[PHONE REDACTED].736 197.62 (270)CREEK TOP 1249 1 2.62 102.62 124.13 678925.[PHONE REDACTED].986 200.42 (300)GRADE BRK 1255 1 24.13 124.13 145.61 678928.[PHONE REDACTED].194 208.12 (300)GRADE BRK 1256 1 45.61 145.61 182.16 678934.[PHONE REDACTED].306 218.07 (334)TOP OF BANK 1257 1 82.16 182.16 STATION (FT) STATION (FT) STATION (FT) STATION (FT) NORTHING (FT) NORTHING (FT) NORTHING (FT) NORTHING (FT) EASTING (FT) EASTING (FT) EASTING (FT) EASTING (FT) ELEV (FT) ELEV (FT) ELEV (FT) ELEV (FT) DESCRIPTION (FT) DESCRIPTION (FT) DESCRIPTION (FT) DESCRIPTION (FT) POINT POINT POINT POINT STATION STATION STATION STATION 0.00 678417.[PHONE REDACTED].226 28.60 (270)CREEK TOP 1311 0 0 0 9.44 678415.[PHONE REDACTED].524 25.29 (268)CREEK TOE 1310 0 9.44 9.44 24.66 678413.[PHONE REDACTED].514 25.73 (304)GRND SHOT 1309 0 24.66 24.66 46.20 678409.[PHONE REDACTED].733 25.91 (304)GRND SHOT 1308 0 46.2 46.2 64.59 678406.[PHONE REDACTED].849 26.57 (268)CREEK TOE 1307 0 64.59 64.59 72.36 678405.[PHONE REDACTED].501 27.76 (276)EDGE WATER 1306 0 72.36 72.36 74.89 678404.[PHONE REDACTED].994 28.52 (787)SET REBAR   1305 0 74.89 74.89 88.74 678402.[PHONE REDACTED].633 28.31 (304)GRND SHOT 1312 0 88.74 88.74 106.63 678399.[PHONE REDACTED].262 30.24 (304)GRND SHOT 1313 1 6.63 106.63 133.90 678394.[PHONE REDACTED].118 30.14 (304)GRND SHOT 1314 1 33.9 133.9 192.61 678384.[PHONE REDACTED].953 30.36 (782)SET HUB/TACK  1304 1 92.61 192.61 BC05 (Woodland Creek) BC05 (Woodland Creek) BC05 (Woodland Creek) BC05 (Woodland Creek) BC06 (Clarks Creek) BC06 (Clarks Creek) BC06 (Clarks Creek) BC06 (Clarks Creek) 20 22 24 26 28 30 32 0 50 100 150 200 250 Elevation (ft) Station (ft) 180 185 190 195 200 205 210 215 220 0 50 100 150 200 Elevation (ft) Station (ft) Page 3 of18 ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Surveyed Crosssections Appendix B STATION (FT) STATION (FT) STATION (FT) STATION (FT) NORTHING (FT) NORTHING (FT) NORTHING (FT) NORTHING (FT) EASTING (FT) EASTING (FT) EASTING (FT) EASTING (FT) ELEV (FT) ELEV (FT) ELEV (FT) ELEV (FT) DESCRIPTION (FT) DESCRIPTION (FT) DESCRIPTION (FT) DESCRIPTION (FT) POINT POINT POINT POINT STATION STATION STATION STATION 0.00 674800.[PHONE REDACTED].467 249.89 (787)SET REBAR   1120 0 0 0 6.03 674794.[PHONE REDACTED].790 248.47 (300)GRADE BRK 1129 0 6.03 6.03 19.43 674780.[PHONE REDACTED].289 242.89 (270)CREEK TOP 1128 0 19.43 19.43 23.24 674776.[PHONE REDACTED].862 238.84 (268)CREEK TOE 1127 0 23.24 23.24 24.60 674775.[PHONE REDACTED].709 239.86 (276)EDGE WATER 1126 0 24.6 24.6 33.85 674766.[PHONE REDACTED].672 239.66 (268)CREEK TOE 1125 0 33.85 33.85 38.72 674761.[PHONE REDACTED].127 242.15 (300)GRADE BRK 1124 0 38.72 38.72 48.89 674751.[PHONE REDACTED].987 247.32 (300)GRADE BRK 1123 0 48.89 48.89 67.86 674732.[PHONE REDACTED].801 254.93 (787)SET REBAR   1122 0 67.86 67.86 STATION (FT) STATION (FT) STATION (FT) STATION (FT) NORTHING (FT) NORTHING (FT) NORTHING (FT) NORTHING (FT) EASTING (FT) EASTING (FT) EASTING (FT) EASTING (FT) ELEV (FT) ELEV (FT) ELEV (FT) ELEV (FT) DESCRIPTION (FT) DESCRIPTION (FT) DESCRIPTION (FT) DESCRIPTION (FT) POINT POINT POINT POINT STATION STATION STATION STATION 0.00 675072.[PHONE REDACTED].524 238.29 (787)SET REBAR   1004 0 0 0 13.22 675066.[PHONE REDACTED].423 230.78 (300)GRADE BRK 1005 0 13.22 13.22 40.18 675056.[PHONE REDACTED].256 216.90 (300)GRADE BRK 1008 0 40.18 40.18 53.82 675050.[PHONE REDACTED].614 217.26 (300)GRADE BRK 1010 0 53.82 53.82 67.43 675045.[PHONE REDACTED].080 217.85 (270)CREEK TOP 1012 0 67.43 67.43 73.93 675043.[PHONE REDACTED].388 214.76 (268)CREEK TOE 1014 0 73.93 73.93 76.01 675042.[PHONE REDACTED].292 215.12 (268)CREEK TOE 1013 0 76.01 76.01 77.65 675040.[PHONE REDACTED].443 217.51 (270)CREEK TOP 1011 0 77.65 77.65 83.25 675038.[PHONE REDACTED].573 221.03 (300)GRADE BRK 1009 0 83.25 83.25 91.28 675035.[PHONE REDACTED].949 227.14 (304)GRND SHOT 1007 0 91.28 91.28 95.71 675033.[PHONE REDACTED].989 231.49 (304)GRND SHOT 1006 0 95.71 95.71 103.61 675030.[PHONE REDACTED].225 236.34 (787)SET REBAR   1003 1 3.61 103.61 BC07 (Clarks Creek) BC07 (Clarks Creek) BC07 (Clarks Creek) BC07 (Clarks Creek) BC08 (Clarks Creek) BC08 (Clarks Creek) BC08 (Clarks Creek) BC08 (Clarks Creek) 220 225 230 235 240 245 250 255 260 0 20 40 60 80 Elevation (ft) Station (ft) 200 205 210 215 220 225 230 235 240 245 0 20 40 60 80 100 120 Elevation (ft) Station (ft) Page 4 of18 ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Surveyed Crosssections Appendix B STATION (FT) STATION (FT) STATION (FT) STATION (FT) NORTHING (FT) NORTHING (FT) NORTHING (FT) NORTHING (FT) EASTING (FT) EASTING (FT) EASTING (FT) EASTING (FT) ELEV (FT) ELEV (FT) ELEV (FT) ELEV (FT) DESCRIPTION (FT) DESCRIPTION (FT) DESCRIPTION (FT) DESCRIPTION (FT) POINT POINT POINT POINT STATION STATION STATION STATION 0.00 677292.[PHONE REDACTED].371 79.01 (320)RET WALL TOE 1302 0 0 0 8.88 677289.[PHONE REDACTED].847 72.62 (787)SET REBAR   1301 0 8.88 8.88 22.03 677285.[PHONE REDACTED].370 67.80 (304)GRND SHOT 1300 0 22.03 22.03 32.73 677282.[PHONE REDACTED].061 65.74 (276)EDGE WATER 1299 0 35.73 35.73 33.25 677281.[PHONE REDACTED].384 63.88 (270)CREEK TOP 1298 0 33.25 33.25 34.63 677281.[PHONE REDACTED].394 64.15 (268)CREEK TOE 1297 0 34.63 34.63 37.95 677280.[PHONE REDACTED].546 64.32 (268)CREEK TOE 1296 0 37.95 37.95 38.98 677280.[PHONE REDACTED].534 65.75 (270)CREEK TOP 1295 0 38.98 38.98 58.96 677274.[PHONE REDACTED].586 73.95 (304)GRND SHOT 1294 0 58.96 58.96 76.75 677269.[PHONE REDACTED].545 84.09 (270)CREEK TOP 1293 0 76.75 76.75 81.99 677267.[PHONE REDACTED].544 84.95 (787)SET REBAR   1292 0 81.99 81.99 STATION (FT) STATION (FT) STATION (FT) STATION (FT) NORTHING (FT) NORTHING (FT) NORTHING (FT) NORTHING (FT) EASTING (FT) EASTING (FT) EASTING (FT) EASTING (FT) ELEV (FT) ELEV (FT) ELEV (FT) ELEV (FT) DESCRIPTION (FT) DESCRIPTION (FT) DESCRIPTION (FT) DESCRIPTION (FT) POINT POINT POINT POINT STATION STATION STATION STATION 0.00 676196.[PHONE REDACTED].674 141.75 (304)GRND SHOT 1349 0 0 0 9.44 676195.[PHONE REDACTED].071 140.57 (334)TOP OF BANK 1341 0 9.44 9.44 30.54 676193.[PHONE REDACTED].064 133.48 (270)CREEK TOP 1342 0 30.54 30.54 35.57 676192.[PHONE REDACTED].074 132.32 (268)CREEK TOE 1343 0 35.57 35.57 43.99 676191.[PHONE REDACTED].451 131.15 (256)CREEK CL 1344 0 43.99 43.99 46.13 676191.[PHONE REDACTED].587 130.99 (268)CREEK TOE 1345 0 46.13 46.13 47.90 676191.[PHONE REDACTED].343 133.02 (300)GRADE BRK 1346 0 47.9 47.9 50.72 676191.[PHONE REDACTED].169 139.45 (322)RET WALL TOP 1348 0 50.72 50.72 59.12 676190.[PHONE REDACTED].514 139.47 (784)SET PK/SPIKE   1339 0 59.12 59.12 BC09 (Upper Meeker Creek West) BC09 (Upper Meeker Creek West) BC09 (Upper Meeker Creek West) BC09 (Upper Meeker Creek West) BC10 (Upper Meeker Creek West) BC10 (Upper Meeker Creek West) BC10 (Upper Meeker Creek West) BC10 (Upper Meeker Creek West) 60 65 70 75 80 85 90 0 20 40 60 80 100 Elevation (ft) Station (ft) 120 125 130 135 140 145 0 20 40 60 80 Elevation (ft) Station (ft) Page 5 of18 ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Surveyed Crosssections Appendix B STATION (FT) STATION (FT) STATION (FT) STATION (FT) NORTHING (FT) NORTHING (FT) NORTHING (FT) NORTHING (FT) EASTING (FT) EASTING (FT) EASTING (FT) EASTING (FT) ELEV (FT) ELEV (FT) ELEV (FT) ELEV (FT) DESCRIPTION (FT) DESCRIPTION (FT) DESCRIPTION (FT) DESCRIPTION (FT) POINT POINT POINT POINT STATION STATION STATION STATION 0.00 677128.[PHONE REDACTED].104 76.73 (304)GRND SHOT 1367 0 0 0 76.73 17.21 677112.[PHONE REDACTED].913 60.36 (300)GRADE BRK 1366 0 17.21 17.21 60.36 23.27 677107.[PHONE REDACTED].664 60.23 (300)GRADE BRK 1365 0 23.27 23.27 60.23 36.22 677095.[PHONE REDACTED].538 57.36 (332)TOE OF BANK 1364 0 36.22 36.22 57.36 68.50 677067.[PHONE REDACTED].186 57.72 (304)GRND SHOT 1363 0 68.5 68.5 57.72 73.85 677062.[PHONE REDACTED].612 57.29 (256)CREEK CL 1362 0 73.85 73.85 57.29 92.35 677045.[PHONE REDACTED].010 57.81 (304)GRND SHOT 1361 0 92.35 92.35 57.81 120.37 677020.[PHONE REDACTED].724 58.56 (270)CREEK TOP 1360 1 20.37 120.37 58.56 126.75 677015.[PHONE REDACTED].615 57.75 (268)CREEK TOE 1358 1 26.75 126.75 57.75 127.35 677014.[PHONE REDACTED].891 57.97 (276)EDGE WATER 1359 1 27.35 127.35 57.97 129.80 677012.[PHONE REDACTED].008 58.07 (268)CREEK TOE 1357 1 29.8 129.8 58.07 133.76 677008.[PHONE REDACTED].760 59.57 (332)TOE OF BANK 1356 1 33.76 133.76 59.57 155.49 676989.[PHONE REDACTED].658 72.54 (304)GRND SHOT 1355 1 55.49 155.49 72.54 196.47 676953.[PHONE REDACTED].254 102.45 (787)SET REBAR   1354 1 96.47 196.47 102.45 STATION (FT) STATION (FT) STATION (FT) STATION (FT) NORTHING (FT) NORTHING (FT) NORTHING (FT) NORTHING (FT) EASTING (FT) EASTING (FT) EASTING (FT) EASTING (FT) ELEV (FT) ELEV (FT) ELEV (FT) ELEV (FT) DESCRIPTION (FT) DESCRIPTION (FT) DESCRIPTION (FT) DESCRIPTION (FT) POINT POINT POINT POINT STATION STATION STATION STATION 0.00 675810.[PHONE REDACTED].831 158.08 (300)GRADE BRK 1400 0 0 0 20.73 675812.[PHONE REDACTED].485 147.99 (322)RET WALL TOP 1401 0 20.73 20.73 35.28 675813.[PHONE REDACTED].974 146.75 (270)CREEK TOP 1402 0 35.28 35.28 37.83 675814.[PHONE REDACTED].512 145.60 (268)CREEK TOE 1403 0 37.83 37.83 38.54 675814.[PHONE REDACTED].225 145.07 (268)CREEK TOE 1404 0 38.54 38.54 39.53 675814.[PHONE REDACTED].207 146.49 (270)CREEK TOP 1405 0 39.53 39.53 45.22 675814.[PHONE REDACTED].878 147.32 (300)GRADE BRK 1406 0 45.22 45.22 57.67 675815.[PHONE REDACTED].278 150.43 (300)GRADE BRK 1407 0 57.67 57.67 59.32 675816.[PHONE REDACTED].923 155.79 (334)TOP OF BANK 1408 0 59.32 59.32 BC11 (Upper Meeker Creek East) BC11 (Upper Meeker Creek East) BC11 (Upper Meeker Creek East) BC11 (Upper 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6222 0 40.55 40.55 44.88 682469.[PHONE REDACTED].471 196.06 (300)GRADE BRK 6221 0 44.88 44.88 54.89 682467.[PHONE REDACTED].340 195.59 (300)GRADE BRK 6220 0 54.89 54.89 58.11 682467.[PHONE REDACTED].516 194.95 (268)CREEK TOE 6219 0 58.11 58.11 63.42 682466.[PHONE REDACTED].757 194.72 (266) CREEK 6218 0 63.42 63.42 71.83 682465.[PHONE REDACTED].049 195.32 (268)CREEK TOE 6217 0 71.83 71.83 90.90 682462.[PHONE REDACTED].857 214.38 (300)GRADE BRK 6216 0 90.9 90.9 111.09 682458.[PHONE REDACTED].770 231.54 (304)GRND SHOT 6215 1 11.09 111.09 124.35 682456.[PHONE REDACTED].844 241.08 (304)GRND SHOT 6214 1 24.35 124.35 STATION (FT) STATION (FT) STATION (FT) STATION (FT) NORTHING (FT) NORTHING (FT) NORTHING (FT) NORTHING (FT) EASTING (FT) EASTING (FT) EASTING (FT) EASTING (FT) ELEV (FT) ELEV (FT) ELEV (FT) ELEV (FT) DESCRIPTION (FT) DESCRIPTION (FT) DESCRIPTION (FT) DESCRIPTION (FT) POINT POINT POINT POINT STATION STATION STATION STATION 0.00 676192.[PHONE REDACTED].421 107.50 (787)SET REBAR   1049 0 0 0 16.89 676181.[PHONE REDACTED].264 94.69 (300)GRADE BRK 1050 0 16.89 16.89 24.02 676176.[PHONE REDACTED].853 91.92 (304)GRND SHOT 1051 0 24.02 24.02 34.94 676170.[PHONE REDACTED].401 88.53 (300)GRADE BRK 1052 0 34.94 34.94 41.83 676165.[PHONE REDACTED].801 88.17 (304)GRND SHOT 1053 0 41.83 41.83 44.92 676163.[PHONE REDACTED].829 87.96 (270)CREEK TOP 1048 0 44.92 44.92 47.34 676162.[PHONE REDACTED].090 87.42 (269)DITCH TOE 1047 0 47.34 47.34 53.43 676158.[PHONE REDACTED].634 87.58 (256)CREEK CL 1046 0 53.43 53.43 58.26 676155.[PHONE REDACTED].666 87.95 (782)SET HUB/TACK  1038 0 58.26 58.26 61.15 676153.[PHONE REDACTED].922 87.95 (269)DITCH TOE 1045 0 61.15 61.15 66.33 676150.[PHONE REDACTED].908 88.55 (270)CREEK TOP 1044 0 66.33 66.33 85.69 676138.[PHONE REDACTED].870 89.97 (304)GRND SHOT 1043 0 85.69 85.69 112.66 676121.[PHONE REDACTED].712 92.46 (304)GRND SHOT 1042 1 12.66 112.66 142.87 676101.[PHONE REDACTED].056 96.99 (304)GRND SHOT 1041 1 42.87 142.87 175.41 676081.[PHONE REDACTED].207 103.86 (300)GRADE BRK 1040 1 75.41 175.41 182.72 676076.[PHONE REDACTED].692 106.71 (787)SET REBAR   1039 1 82.72 182.72 BC13 (Rody Creek) BC13 (Rody Creek) BC13 (Rody Creek) BC13 (Rody Creek) XS399 (Clarks Creek) XS399 (Clarks Creek) XS399 (Clarks Creek) XS399 (Clarks Creek) 80 85 90 95 100 105 110 0 50 100 150 200 Elevation (ft) Station (ft) 180 190 200 210 220 230 240 250 260 0 50 100 150 Elevation (ft) Station (ft) Page 7 of18 ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Surveyed Crosssections Appendix B STATION (FT) STATION (FT) STATION (FT) STATION (FT) NORTHING (FT) NORTHING (FT) NORTHING (FT) NORTHING (FT) EASTING (FT) EASTING (FT) EASTING (FT) EASTING (FT) ELEV (FT) ELEV (FT) ELEV (FT) ELEV (FT) DESCRIPTION (FT) DESCRIPTION (FT) DESCRIPTION (FT) DESCRIPTION (FT) POINT POINT POINT POINT STATION STATION STATION STATION 0.00 675167.[PHONE REDACTED].521 221.44 (787)SET REBAR   1016 0 0 0 27.27 675146.[PHONE REDACTED].839 210.91 (304)GRND SHOT 1019 0 27.27 27.27 45.40 675132.[PHONE REDACTED].698 205.28 (304)GRND SHOT 1021 0 45.4 45.4 48.80 675130.[PHONE REDACTED].923 205.25 (304)GRND SHOT 1022 0 48.8 48.8 54.91 675125.[PHONE REDACTED].921 205.84 (270)CREEK TOP 1025 0 54.91 54.91 58.17 675123.[PHONE REDACTED].058 198.07 (268)CREEK TOE 1027 0 58.17 58.17 59.13 675122.[PHONE REDACTED].684 197.36 (268)CREEK TOE 1028 0 59.13 59.13 64.33 675118.[PHONE REDACTED].083 206.61 (270)CREEK TOP 1026 0 64.33 64.33 68.94 675114.[PHONE REDACTED].099 209.65 (304)GRND SHOT 1024 0 68.94 68.94 72.83 675112.[PHONE REDACTED].640 210.41 (304)GRND SHOT 1023 0 72.83 72.83 84.63 675103.[PHONE REDACTED].359 219.72 (304)GRND SHOT 1020 0 84.63 84.63 93.27 675096.[PHONE REDACTED].012 226.39 (300)GRADE BRK 1018 0 93.27 93.27 96.36 675094.[PHONE REDACTED].034 227.27 (300)GRADE BRK 1017 0 96.36 96.36 106.36 675086.[PHONE REDACTED].579 232.61 (787)SET REBAR   1015 1 6.36 106.36 STATION (FT) STATION (FT) STATION (FT) STATION (FT) NORTHING (FT) NORTHING (FT) NORTHING (FT) NORTHING (FT) EASTING (FT) EASTING (FT) EASTING (FT) EASTING (FT) ELEV (FT) ELEV (FT) ELEV (FT) ELEV (FT) DESCRIPTION (FT) DESCRIPTION (FT) DESCRIPTION (FT) DESCRIPTION (FT) POINT POINT POINT POINT STATION STATION STATION STATION 0.00 676282.[PHONE REDACTED].791 104.59 (787)SET REBAR   1056 0 0 0 12.94 676272.[PHONE REDACTED].287 97.94 (304)GRND SHOT 1057 0 12.94 12.94 38.81 676251.[PHONE REDACTED].364 89.30 (304)GRND SHOT 1058 0 38.81 38.81 50.77 676241.[PHONE REDACTED].369 86.34 (300)GRADE BRK 1059 0 50.77 50.77 70.59 676225.[PHONE REDACTED].832 84.08 (268)CREEK TOE 1060 0 70.59 70.59 80.47 676217.[PHONE REDACTED].421 84.45 (270)CREEK TOP 1061 0 80.47 80.47 82.18 676215.[PHONE REDACTED].990 84.22 (268)CREEK TOE 1062 0 82.18 82.18 87.31 676211.[PHONE REDACTED].100 84.05 (268)CREEK TOE 1063 0 87.31 87.31 91.69 676207.[PHONE REDACTED].502 84.56 (300)GRADE BRK 1064 0 91.69 91.69 99.47 676201.[PHONE REDACTED].960 86.94 (300)GRADE BRK 1065 0 99.47 99.47 116.58 676187.[PHONE REDACTED].049 89.52 (304)GRND SHOT 1066 1 16.58 116.58 128.48 676178.[PHONE REDACTED].169 92.65 (300)GRADE BRK 1067 1 28.48 128.48 143.54 676165.[PHONE REDACTED].925 96.83 (787)SET REBAR   1055 1 43.54 143.54 XS413 (Clarks Creek) XS413 (Clarks Creek) XS413 (Clarks Creek) XS413 (Clarks Creek) XS411 (Clarks Creek) XS411 (Clarks Creek) XS411 (Clarks Creek) XS411 (Clarks Creek) 80 85 90 95 100 105 110 0 50 100 150 200 Elevation (ft) Station (ft) 180 190 200 210 220 230 240 0 20 40 60 80 100 120 Elevation (ft) Station (ft) Page 8 of18 ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Surveyed Crosssections Appendix B STATION (FT) STATION (FT) STATION (FT) STATION (FT) NORTHING (FT) NORTHING (FT) NORTHING (FT) NORTHING (FT) EASTING (FT) EASTING (FT) EASTING (FT) EASTING (FT) ELEV (FT) ELEV (FT) ELEV (FT) ELEV (FT) DESCRIPTION (FT) DESCRIPTION (FT) DESCRIPTION (FT) DESCRIPTION (FT) POINT POINT POINT POINT STATION STATION STATION STATION 0.00 676318.[PHONE REDACTED].215 91.72 (787)SET REBAR   1069 0 0 0 12.69 676307.[PHONE REDACTED].777 86.09 (300)GRADE BRK 1070 0 12.69 12.69 31.86 676291.[PHONE REDACTED].943 79.57 (300)GRADE BRK 1071 0 31.86 31.86 57.95 676268.[PHONE REDACTED].710 80.80 (304)GRND SHOT 1072 0 57.95 57.95 69.18 676260.[PHONE REDACTED].191 80.99 (270)CREEK TOP 1073 0 69.18 69.18 70.72 676258.[PHONE REDACTED].547 80.62 (268)CREEK TOE 1074 0 70.72 70.72 75.88 676254.[PHONE REDACTED].792 80.48 (268)CREEK TOE 1075 0 75.88 75.88 77.78 676252.[PHONE REDACTED].462 80.70 (270)CREEK TOP 1076 0 77.78 77.78 90.82 676241.[PHONE REDACTED].287 81.44 (300)GRADE BRK 1077 0 90.82 90.82 107.65 676227.[PHONE REDACTED].801 93.32 (300)GRADE BRK 1078 1 7.65 107.65 110.63 676224.[PHONE REDACTED].683 95.15 (787)SET REBAR   1068 1 10.63 110.63 STATION (FT) STATION (FT) STATION (FT) STATION (FT) NORTHING (FT) NORTHING (FT) NORTHING (FT) NORTHING (FT) EASTING (FT) EASTING (FT) EASTING (FT) EASTING (FT) ELEV (FT) ELEV (FT) ELEV (FT) ELEV (FT) DESCRIPTION (FT) DESCRIPTION (FT) DESCRIPTION (FT) DESCRIPTION (FT) POINT POINT POINT POINT STATION STATION STATION STATION 0.00 676370.[PHONE REDACTED].088 94.42 (787)SET REBAR   1080 0 0 0 20.78 676351.[PHONE REDACTED].891 81.01 (300)GRADE BRK 1081 0 20.78 20.78 29.16 676343.[PHONE REDACTED].025 78.64 (270)CREEK TOP 1082 0 29.16 29.16 32.84 676340.[PHONE REDACTED].467 76.00 (268)CREEK TOE 1083 0 32.84 32.84 37.74 676335.[PHONE REDACTED].288 76.27 (276)EDGE WATER 1084 0 37.74 37.74 41.61 676332.[PHONE REDACTED].046 76.25 (304)GRND SHOT 1085 0 41.61 41.61 54.47 676320.[PHONE REDACTED].788 76.01 (276)EDGE WATER 1087 0 54.47 54.47 79.98 676297.[PHONE REDACTED].691 76.38 (300)GRADE BRK 1088 0 79.98 79.98 109.50 676270.[PHONE REDACTED].042 95.05 (787)SET REBAR   1079 1 9.5 109.5 XS415 (Clarks Creek) XS415 (Clarks Creek) XS415 (Clarks Creek) XS415 (Clarks Creek) XS414 (Clarks Creek) XS414 (Clarks Creek) XS414 (Clarks Creek) XS414 (Clarks Creek) 70 75 80 85 90 95 100 0 20 40 60 80 100 120 Elevation (ft) Station (ft) 70 75 80 85 90 95 100 0 20 40 60 80 100 120 Elevation (ft) Station (ft) Page 9 of18 ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Surveyed Crosssections Appendix B STATION (FT) STATION (FT) STATION (FT) STATION (FT) NORTHING (FT) NORTHING (FT) NORTHING (FT) NORTHING (FT) EASTING (FT) EASTING (FT) EASTING (FT) EASTING (FT) ELEV (FT) ELEV (FT) ELEV (FT) ELEV (FT) DESCRIPTION (FT) DESCRIPTION (FT) DESCRIPTION (FT) DESCRIPTION (FT) POINT POINT POINT POINT STATION STATION STATION STATION 0.00 676603.[PHONE REDACTED].880 78.84 (787)SET REBAR   1105 0 0 0 34.12 676599.[PHONE REDACTED].812 68.67 (304)GRND SHOT 1104 0 34.12 34.12 47.22 676598.[PHONE REDACTED].831 69.10 (300)GRADE BRK 1103 0 47.22 47.22 78.44 676594.[PHONE REDACTED].857 65.10 (270)CREEK TOP 1102 0 78.44 78.44 83.70 676594.[PHONE REDACTED].087 62.03 (268)CREEK TOE 1101 0 83.7 83.7 95.79 676592.[PHONE REDACTED].099 61.62 (304)GRND SHOT 1100 0 95.79 95.79 112.03 676591.[PHONE REDACTED].243 61.67 (276)EDGE WATER 1099 1 12.03 112.03 123.15 676589.[PHONE REDACTED].290 61.57 (787)SET REBAR   1090 1 23.15 123.15 134.99 676588.[PHONE REDACTED].062 61.17 (304)GRND SHOT 1098 1 34.99 134.99 140.54 676588.[PHONE REDACTED].583 61.73 (304)GRND SHOT 1097 1 40.54 140.54 148.74 676587.[PHONE REDACTED].728 61.82 (276)EDGE WATER 1096 1 48.74 148.74 155.03 676586.[PHONE REDACTED].975 61.50 (268)CREEK TOE 1095 1 55.03 155.03 162.75 676585.[PHONE REDACTED].653 64.80 (270)CREEK TOP 1094 1 62.75 162.75 172.64 676583.[PHONE REDACTED].423 67.00 (300)GRADE BRK 1093 1 72.64 172.64 181.07 676583.[PHONE REDACTED].844 68.75 (300)GRADE BRK 1092 1 81.07 181.07 189.19 676582.[PHONE REDACTED].939 74.56 (787)SET REBAR   1091 1 89.19 189.19 STATION (FT) STATION (FT) STATION (FT) STATION (FT) NORTHING (FT) NORTHING (FT) NORTHING (FT) NORTHING (FT) EASTING (FT) EASTING (FT) EASTING (FT) EASTING (FT) ELEV (FT) ELEV (FT) ELEV (FT) ELEV (FT) DESCRIPTION (FT) DESCRIPTION (FT) DESCRIPTION (FT) DESCRIPTION (FT) POINT POINT POINT POINT STATION STATION STATION STATION 0.00 677331.[PHONE REDACTED].881 43.64 (787)SET REBAR   1108 0 0 0 27.97 677317.[PHONE REDACTED].905 40.64 (270)CREEK TOP 1109 0 27.97 27.97 40.41 677311.[PHONE REDACTED].676 37.88 (300)GRADE BRK 1110 0 40.41 40.41 46.13 677308.[PHONE REDACTED].625 36.80 (268)CREEK TOE 1111 0 46.13 46.13 52.57 677305.[PHONE REDACTED].197 37.05 (276)EDGE WATER 1112 0 52.57 52.57 55.72 677303.[PHONE REDACTED].928 36.45 (304)GRND SHOT 1113 0 55.72 55.72 67.71 677297.[PHONE REDACTED].304 36.71 (268)CREEK TOE 1114 0 67.71 67.71 69.46 677296.[PHONE REDACTED].816 38.26 (300)GRADE BRK 1115 0 69.46 69.46 80.26 677291.[PHONE REDACTED].165 42.50 (270)CREEK TOP 1116 0 80.26 80.26 87.38 677287.[PHONE REDACTED].325 42.84 (633)GVL EDGE 1117 0 87.38 87.38 102.66 677280.[PHONE REDACTED].548 43.13 (633)GVL EDGE 1118 1 2.66 102.66 106.66 677278.[PHONE REDACTED].017 43.62 (787)SET REBAR   1107 1 6.66 106.66 XS418 (Clarks Creek) XS418 (Clarks Creek) XS418 (Clarks Creek) XS418 (Clarks Creek) XS416 (Clarks Creek) XS416 (Clarks Creek) XS416 (Clarks Creek) XS416 (Clarks Creek) 30 32 34 36 38 40 42 44 46 0 20 40 60 80 100 120 Elevation (ft) Station (ft) 50 55 60 65 70 75 80 85 0 50 100 150 200 Elevation (ft) Station (ft) Page 10 of18 ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Surveyed Crosssections Appendix B STATION (FT) STATION (FT) STATION (FT) STATION (FT) NORTHING (FT) NORTHING (FT) NORTHING (FT) NORTHING (FT) EASTING (FT) EASTING (FT) EASTING (FT) EASTING (FT) ELEV (FT) ELEV (FT) ELEV (FT) ELEV (FT) DESCRIPTION (FT) DESCRIPTION (FT) DESCRIPTION (FT) DESCRIPTION (FT) POINT POINT POINT POINT STATION STATION STATION STATION 0.00 683744.[PHONE REDACTED].978 29.36 (304)GRND SHOT 1217 0 0 0 12.09 683753.[PHONE REDACTED].328 29.42 (270)CREEK TOP 1216 0 12.09 12.09 15.09 683755.[PHONE REDACTED].405 26.39 (268)CREEK TOE 1215 0 15.09 15.09 22.64 683761.[PHONE REDACTED].621 26.26 (272)DITCH CL 1213 0 22.64 22.64 26.49 683763.[PHONE REDACTED].285 26.94 (276)EDGE WATER 1214 0 26.49 26.49 27.85 683764.[PHONE REDACTED].218 26.79 (268)CREEK TOE 1212 0 27.85 27.85 33.78 683769.[PHONE REDACTED].316 29.78 (270)CREEK TOP 1211 0 33.78 33.78 52.55 683782.[PHONE REDACTED].290 29.67 (304)GRND SHOT 1210 0 52.55 52.55 STATION (FT) STATION (FT) STATION (FT) STATION (FT) NORTHING (FT) NORTHING (FT) NORTHING (FT) NORTHING (FT) EASTING (FT) EASTING (FT) EASTING (FT) EASTING (FT) ELEV (FT) ELEV (FT) ELEV (FT) ELEV (FT) DESCRIPTION (FT) DESCRIPTION (FT) DESCRIPTION (FT) DESCRIPTION (FT) POINT POINT POINT POINT STATION STATION STATION STATION 0.00 683116.[PHONE REDACTED].800 64.36 (787)SET REBAR   1196 0 0 0 9.35 683111.[PHONE REDACTED].736 60.33 (300)GRADE BRK 1197 0 9.35 9.35 14.63 683108.[PHONE REDACTED].217 55.03 (300)GRADE BRK 1198 0 14.63 14.63 23.92 683103.[PHONE REDACTED].127 48.28 (300)GRADE BRK 1199 0 23.92 23.92 31.18 683099.[PHONE REDACTED].271 46.41 (268)CREEK TOE 1200 0 31.18 31.18 34.38 683098.[PHONE REDACTED].989 46.03 (272)DITCH CL 1201 0 34.38 34.38 35.74 683097.[PHONE REDACTED].140 46.38 (276)EDGE WATER 1203 0 35.74 35.74 36.93 683096.[PHONE REDACTED].155 46.12 (268)CREEK TOE 1202 0 36.93 36.93 39.37 683095.[PHONE REDACTED].228 49.34 (276)EDGE WATER 1204 0 39.37 39.37 44.74 683092.[PHONE REDACTED].783 49.63 (787)SET REBAR   1195 0 44.74 44.74 57.95 683085.[PHONE REDACTED].004 48.67 (304)GRND SHOT 1205 0 57.95 57.95 XS421 (Diru Creek) XS421 (Diru Creek) XS421 (Diru Creek) XS421 (Diru Creek) XS422 (Diru Creek) XS422 (Diru Creek) XS422 (Diru Creek) XS422 (Diru Creek) 20 22 24 26 28 30 32 0 10 20 30 40 50 60 Elevation (ft) Station (ft) 40 45 50 55 60 65 70 0 20 40 60 80 Elevation (ft) Station (ft) Page 11 of18 ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Surveyed Crosssections Appendix B STATION (FT) STATION (FT) STATION (FT) STATION (FT) NORTHING (FT) NORTHING (FT) NORTHING (FT) NORTHING (FT) EASTING (FT) EASTING (FT) EASTING (FT) EASTING (FT) ELEV (FT) ELEV (FT) ELEV (FT) ELEV (FT) DESCRIPTION (FT) DESCRIPTION (FT) DESCRIPTION (FT) DESCRIPTION (FT) POINT POINT POINT POINT STATION STATION STATION STATION 0.00 682535.[PHONE REDACTED].167 108.47 (787)SET REBAR   1180 0 0 0 19.57 682530.[PHONE REDACTED].146 94.60 (304)GRND SHOT 1181 0 19.57 19.57 26.77 682528.[PHONE REDACTED].125 90.10 (300)GRADE BRK 1182 0 26.77 26.77 36.29 682526.[PHONE REDACTED].356 83.54 (332)TOE OF BANK 1183 0 36.29 36.29 50.20 682523.[PHONE REDACTED].837 81.87 (304)GRND SHOT 1184 0 50.2 50.2 58.16 682521.[PHONE REDACTED].561 81.09 (269)DITCH TOE 1185 0 58.16 58.16 61.13 682520.[PHONE REDACTED].437 81.23 (276)EDGE WATER 1187 0 61.13 61.13 62.98 682519.[PHONE REDACTED].234 81.04 (269)DITCH TOE 1186 0 62.98 62.98 71.41 682517.[PHONE REDACTED].409 84.03 (300)GRADE BRK 1188 0 71.41 71.41 77.68 682516.[PHONE REDACTED].488 84.79 (300)GRADE BRK 1189 0 77.68 77.68 97.00 682511.[PHONE REDACTED].215 96.06 (304)GRND SHOT 1191 0 97 97 111.67 682508.[PHONE REDACTED].438 109.06 (787)SET REBAR   1190 1 11.67 111.67 STATION (FT) STATION (FT) STATION (FT) STATION (FT) NORTHING (FT) NORTHING (FT) NORTHING (FT) NORTHING (FT) EASTING (FT) EASTING (FT) EASTING (FT) EASTING (FT) ELEV (FT) ELEV (FT) ELEV (FT) ELEV (FT) DESCRIPTION (FT) DESCRIPTION (FT) DESCRIPTION (FT) DESCRIPTION (FT) POINT POINT POINT POINT STATION STATION STATION STATION 0.00 681515.[PHONE REDACTED].425 186.14 (787)SET REBAR   1162 0 0 0 15.95 681513.[PHONE REDACTED].276 172.65 (304)GRND SHOT 1163 0 15.95 15.95 21.67 681512.[PHONE REDACTED].954 169.29 (270)CREEK TOP 1164 0 21.67 21.67 28.46 681512.[PHONE REDACTED].699 158.14 (269)DITCH TOE 1165 0 28.46 28.46 28.86 681512.[PHONE REDACTED].094 158.17 (276)EDGE WATER 1166 0 28.86 28.86 37.85 681511.[PHONE REDACTED].029 158.46 (782)SET HUB/TACK  1161 0 37.85 37.85 41.77 681510.[PHONE REDACTED].926 158.75 (276)EDGE WATER 1167 0 41.77 41.77 47.02 681509.[PHONE REDACTED].143 159.84 (270)CREEK TOP 1168 0 47.02 47.02 65.96 681507.[PHONE REDACTED].950 175.81 (304)GRND SHOT 1169 0 65.96 65.96 78.41 681506.[PHONE REDACTED].337 187.14 (787)SET REBAR   1170 0 78.41 78.41 XS423 (Diru Creek) XS423 (Diru Creek) XS423 (Diru Creek) XS423 (Diru Creek) XS430 (Diru Creek) XS430 (Diru Creek) XS430 (Diru Creek) XS430 (Diru Creek) 60 70 80 90 100 110 120 0 20 40 60 80 100 120 Elevation (ft) Station (ft) 150 155 160 165 170 175 180 185 190 0 20 40 60 80 100 Elevation (ft) Station (ft) Page 12 of18 ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Surveyed Crosssections Appendix B STATION (FT) STATION (FT) STATION (FT) STATION (FT) NORTHING (FT) NORTHING (FT) NORTHING (FT) NORTHING (FT) EASTING (FT) EASTING (FT) EASTING (FT) EASTING (FT) ELEV (FT) ELEV (FT) ELEV (FT) ELEV (FT) DESCRIPTION (FT) DESCRIPTION (FT) DESCRIPTION (FT) DESCRIPTION (FT) POINT POINT POINT POINT STATION STATION STATION STATION 0.00 680611.[PHONE REDACTED].388 269.64 (787)SET REBAR   1154 0 0 0 14.67 680610.[PHONE REDACTED].014 261.25 (304)GRND SHOT 1153 0 14.67 14.67 29.26 680607.[PHONE REDACTED].422 251.78 (304)GRND SHOT 1152 0 29.26 29.26 41.89 680605.[PHONE REDACTED].878 243.10 (300)GRADE BRK 1151 0 41.89 41.89 44.10 680605.[PHONE REDACTED].064 237.83 (268)CREEK TOE 1150 0 44.1 44.1 49.34 680604.[PHONE REDACTED].236 237.44 (268)CREEK TOE 1149 0 49.34 49.34 56.71 680603.[PHONE REDACTED].502 239.33 (300)GRADE BRK 1148 0 56.71 56.71 62.61 680602.[PHONE REDACTED].321 239.78 (782)SET HUB/TACK  1144 0 62.61 62.61 63.57 680602.[PHONE REDACTED].273 239.73 (300)GRADE BRK 1147 0 63.57 63.57 78.22 680600.[PHONE REDACTED].854 250.32 (304)GRND SHOT 1146 0 78.22 78.22 92.42 680598.[PHONE REDACTED].884 261.14 (787)SET REBAR   1145 0 92.42 92.42 STATION (FT) STATION (FT) STATION (FT) STATION (FT) NORTHING (FT) NORTHING (FT) NORTHING (FT) NORTHING (FT) EASTING (FT) EASTING (FT) EASTING (FT) EASTING (FT) ELEV (FT) ELEV (FT) ELEV (FT) ELEV (FT) DESCRIPTION (FT) DESCRIPTION (FT) DESCRIPTION (FT) DESCRIPTION (FT) POINT POINT POINT POINT STATION STATION STATION STATION 0.00 680094.[PHONE REDACTED].093 295.26 (787)SET REBAR   1135 0 0 0 16.40 680101.[PHONE REDACTED].967 285.37 (304)GRND SHOT 1136 0 16.4 16.4 34.26 680108.[PHONE REDACTED].158 274.33 (268)CREEK TOE 1137 0 34.26 34.26 38.50 680110.[PHONE REDACTED].008 274.07 (782)SET HUB/TACK  1134 0 38.5 38.5 48.08 680114.[PHONE REDACTED].695 274.14 (268)CREEK TOE 1138 0 48.08 48.08 62.82 680120.[PHONE REDACTED].058 282.60 (304)GRND SHOT 1139 0 62.82 62.82 79.12 680127.[PHONE REDACTED].834 295.18 (787)SET REBAR   1140 0 79.12 79.12 XS437 (Diru Creek) XS437 (Diru Creek) XS437 (Diru Creek) XS437 (Diru Creek) XS440 (Diru Creek) XS440 (Diru Creek) XS440 (Diru Creek) XS440 (Diru Creek) 220 230 240 250 260 270 280 0 20 40 60 80 100 Elevation (ft) Station (ft) 260 265 270 275 280 285 290 295 300 0 20 40 60 80 100 Elevation (ft) Station (ft) Page 13 of18 ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Surveyed Crosssections Appendix B STATION (FT) STATION (FT) STATION (FT) STATION (FT) NORTHING (FT) NORTHING (FT) NORTHING (FT) NORTHING (FT) EASTING (FT) EASTING (FT) EASTING (FT) EASTING (FT) ELEV (FT) ELEV (FT) ELEV (FT) ELEV (FT) DESCRIPTION (FT) DESCRIPTION (FT) DESCRIPTION (FT) DESCRIPTION (FT) POINT POINT POINT POINT STATION STATION STATION STATION 0+00.00 679964.[PHONE REDACTED].306 381.98 (787)SET REBAR   1135 0 0 0 0+04.42 679961.[PHONE REDACTED].772 380.55 (304)GRND SHOT 1136 0 16.4 16.4 0+22.68 679950.[PHONE REDACTED].081 368.34 (304)GRND SHOT 1137 0 34.26 34.26 0+50.94 679932.[PHONE REDACTED].226 346.78 (268)CREEK TOE 1134 0 38.5 38.5 0+58.17 679928.[PHONE REDACTED].891 346.70 (256)CREEK CL 1138 0 48.08 48.08 0+63.49 679924.[PHONE REDACTED].068 346.59 (268)CREEK TOE 1139 0 62.82 62.82 0+80.99 679913.[PHONE REDACTED].782 353.33 (304)GRND SHOT 1140 0 79.12 79.12 1+02.65 679900.[PHONE REDACTED].756 362.51 (304)GRND SHOT 1+22.22 679888.[PHONE REDACTED].125 371.59 (787)SET REBAR   STATION (FT) STATION (FT) STATION (FT) STATION (FT) NORTHING (FT) NORTHING (FT) NORTHING (FT) NORTHING (FT) EASTING (FT) EASTING (FT) EASTING (FT) EASTING (FT) ELEV (FT) ELEV (FT) ELEV (FT) ELEV (FT) DESCRIPTION (FT) DESCRIPTION (FT) DESCRIPTION (FT) DESCRIPTION (FT) POINT POINT POINT POINT STATION STATION STATION STATION 0.00 681536.[PHONE REDACTED].959 269.53 (782)SET HUB/TACK  1437 0 0 0 3.96 681536.[PHONE REDACTED].914 268.90 (270)CREEK TOP 1438 0 3.96 3.96 15.13 681536.[PHONE REDACTED].088 254.64 (268)CREEK TOE 1439 0 15.13 15.13 20.04 681536.[PHONE REDACTED].000 253.44 (256)CREEK CL 1440 0 20.04 20.04 27.09 681535.[PHONE REDACTED].051 254.04 (268)CREEK TOE 1441 0 27.09 27.09 33.04 681535.[PHONE REDACTED].998 260.27 (300)GRADE BRK 1442 0 33.04 33.04 48.69 681535.[PHONE REDACTED].648 275.88 (304)GRND SHOT 1443 0 48.69 48.69 73.22 681535.[PHONE REDACTED].179 291.60 (782)SET HUB/TACK  1436 0 73.22 73.22 XS446 (Rody Creek) XS446 (Rody Creek) XS446 (Rody Creek) XS446 (Rody Creek) XS456 (Rody Creek) XS456 (Rody Creek) XS456 (Rody Creek) XS456 (Rody Creek) 240 250 260 270 280 290 300 0 20 40 60 80 Elevation (ft) Station (ft) 260 280 300 320 340 360 380 400 0 2 4 6 8 10 Elevation (ft) Station (ft) Page 14 of18 ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Surveyed Crosssections Appendix B STATION (FT) STATION (FT) STATION (FT) STATION (FT) NORTHING (FT) NORTHING (FT) NORTHING (FT) NORTHING (FT) EASTING (FT) EASTING (FT) EASTING (FT) EASTING (FT) ELEV (FT) ELEV (FT) ELEV (FT) ELEV (FT) DESCRIPTION (FT) DESCRIPTION (FT) DESCRIPTION (FT) DESCRIPTION (FT) POINT POINT POINT POINT STATION STATION STATION STATION 0.00 683763.[PHONE REDACTED].616 109.28 (304)GRND SHOT 1433 0 0 0 12.40 683759.[PHONE REDACTED].404 100.55 (332)TOE OF BANK 1432 0 12.4 12.4 32.09 683753.[PHONE REDACTED].129 99.40 (270)CREEK TOP 1431 0 32.09 32.09 36.96 683751.[PHONE REDACTED].756 95.31 (268)CREEK TOE 1430 0 36.96 36.96 41.25 683750.[PHONE REDACTED].842 95.77 (300)GRADE BRK 1429 0 41.25 41.25 43.16 683750.[PHONE REDACTED].652 95.26 (276)EDGE WATER 1428 0 43.16 43.16 43.68 683749.[PHONE REDACTED].154 95.27 (256)CREEK CL 1427 0 43.68 43.68 46.36 683749.[PHONE REDACTED].701 95.42 (300)GRADE BRK 1426 0 46.36 46.36 49.05 683748.[PHONE REDACTED].253 96.07 (300)GRADE BRK 1425 0 49.05 49.05 53.70 683746.[PHONE REDACTED].680 96.80 (300)GRADE BRK 1424 0 53.7 53.7 55.78 683746.[PHONE REDACTED].654 95.69 (300)GRADE BRK 1423 0 55.78 55.78 59.64 683744.[PHONE REDACTED].288 95.64 (276)EDGE WATER 1422 0 59.64 59.64 62.06 683744.[PHONE REDACTED].622 95.37 (256)CREEK CL 1421 0 62.06 62.06 68.93 683742.[PHONE REDACTED].155 95.84 (268)CREEK TOE 1420 0 68.93 68.93 76.81 683739.[PHONE REDACTED].647 101.23 (270)CREEK TOP 1419 0 76.81 76.81 79.40 683738.[PHONE REDACTED].114 101.49 (300)GRADE BRK 1418 0 79.4 79.4 92.99 683734.[PHONE REDACTED].036 109.59 (787)SET REBAR   1417 0 92.99 92.99 STATION (FT) STATION (FT) STATION (FT) STATION (FT) NORTHING (FT) NORTHING (FT) NORTHING (FT) NORTHING (FT) EASTING (FT) EASTING (FT) EASTING (FT) EASTING (FT) ELEV (FT) ELEV (FT) ELEV (FT) ELEV (FT) DESCRIPTION (FT) DESCRIPTION (FT) DESCRIPTION (FT) DESCRIPTION (FT) POINT POINT POINT POINT STATION STATION STATION STATION 0.00 684689.[PHONE REDACTED].877 58.44 (304)GRND SHOT 6330 0 0 0 27.09 684664.[PHONE REDACTED].428 45.66 (300)GRADE BRK 6331 0 27.09 27.09 46.96 684646.[PHONE REDACTED].434 45.74 (300)GRADE BRK 6332 0 46.96 46.96 64.92 684629.[PHONE REDACTED].766 45.01 (270)CREEK TOP 6333 0 64.92 64.92 67.68 684626.[PHONE REDACTED].741 44.04 (268)CREEK TOE 6334 0 67.68 67.68 74.98 684619.[PHONE REDACTED].315 43.95 (268)CREEK TOE 6335 0 74.98 74.98 78.42 684616.[PHONE REDACTED].526 45.30 (270)CREEK TOP 6336 0 78.42 78.42 100.29 684596.[PHONE REDACTED].239 44.95 (304)GRND SHOT 6337 1 0.29 100.29 129.60 684568.[PHONE REDACTED].573 45.48 (304)GRND SHOT 6338 1 29.6 129.6 170.64 684530.[PHONE REDACTED].042 46.96 (304)GRND SHOT 6339 1 70.64 170.64 193.55 684508.[PHONE REDACTED].122 45.80 (300)GRADE BRK 6340 1 93.55 193.55 217.39 684486.[PHONE REDACTED].529 50.71 (304)GRND SHOT 6341 2 17.39 217.39 242.64 684462.[PHONE REDACTED].430 62.07 (304)GRND SHOT 6342 2 42.64 242.64 XS473 (Rody Creek) XS473 (Rody Creek) XS473 (Rody Creek) XS473 (Rody Creek) XS468 (Rody Creek) XS468 (Rody Creek) XS468 (Rody Creek) XS468 (Rody Creek) 80 85 90 95 100 105 110 115 0 20 40 60 80 100 Elevation (ft) Station (ft) 30 35 40 45 50 55 60 65 70 0 50 100 150 200 250 300 Elevation (ft) Station (ft) Page 15 of18 ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Surveyed Crosssections Appendix B STATION (FT) STATION (FT) STATION (FT) STATION (FT) NORTHING (FT) NORTHING (FT) NORTHING (FT) NORTHING (FT) EASTING (FT) EASTING (FT) EASTING (FT) EASTING (FT) ELEV (FT) ELEV (FT) ELEV (FT) ELEV (FT) DESCRIPTION (FT) DESCRIPTION (FT) DESCRIPTION (FT) DESCRIPTION (FT) POINT POINT POINT POINT STATION STATION STATION STATION 0.00 680252.[PHONE REDACTED].930 108.32 (787)SET REBAR   1230 0 0 0 5.37 680254.[PHONE REDACTED].098 107.47 (270)CREEK TOP 1235 0 5.37 5.37 7.26 680254.[PHONE REDACTED].971 104.76 (268)CREEK TOE 1234 0 7.26 7.26 10.02 680255.[PHONE REDACTED].677 104.72 (268)CREEK TOE 1233 0 10.02 10.02 12.46 680255.[PHONE REDACTED].101 107.05 (270)CREEK TOP 1232 0 12.46 12.46 23.80 680257.[PHONE REDACTED].360 107.79 (787)SET REBAR   1231 0 23.8 23.8 STATION (FT) STATION (FT) STATION (FT) STATION (FT) NORTHING (FT) NORTHING (FT) NORTHING (FT) NORTHING (FT) EASTING (FT) EASTING (FT) EASTING (FT) EASTING (FT) ELEV (FT) ELEV (FT) ELEV (FT) ELEV (FT) DESCRIPTION (FT) DESCRIPTION (FT) DESCRIPTION (FT) DESCRIPTION (FT) POINT POINT POINT POINT STATION STATION STATION STATION 0.00 677001.[PHONE REDACTED].834 125.79 (304)GRND SHOT 1336 0 0 0 9.26 677002.[PHONE REDACTED].968 125.31 (334)TOP OF BANK 1335 0 9.26 9.26 19.90 677004.[PHONE REDACTED].465 121.99 (270)CREEK TOP 1334 0 19.9 19.9 21.31 677004.[PHONE REDACTED].864 119.80 (268)CREEK TOE 1333 0 21.31 21.31 22.08 677004.[PHONE REDACTED].616 120.18 (276)EDGE WATER 1332 0 22.08 22.08 24.21 677005.[PHONE REDACTED].720 120.04 (256)CREEK CL 1331 0 24.21 24.21 28.13 677005.[PHONE REDACTED].585 120.36 (268)CREEK TOE 1330 0 28.13 28.13 31.98 677006.[PHONE REDACTED].387 123.22 (270)CREEK TOP 1329 0 31.98 31.98 48.87 677009.[PHONE REDACTED].050 128.36 (334)TOP OF BANK 1328 0 48.87 48.87 67.34 677012.[PHONE REDACTED].279 130.32 (787)SET REBAR   1327 0 67.34 67.34 XS477 (Woodland Creek) XS477 (Woodland Creek) XS477 (Woodland Creek) XS477 (Woodland Creek) XS485 (Silver Creek) XS485 (Silver Creek) XS485 (Silver Creek) XS485 (Silver Creek) 110 115 120 125 130 135 0 20 40 60 80 Elevation (ft) Station (ft) 100 101 102 103 104 105 106 107 108 109 0 5 10 15 20 25 Elevation (ft) Station (ft) Page 16 of18 ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Surveyed Crosssections Appendix B STATION (FT) STATION (FT) STATION (FT) STATION (FT) NORTHING (FT) NORTHING (FT) NORTHING (FT) NORTHING (FT) EASTING (FT) EASTING (FT) EASTING (FT) EASTING (FT) ELEV (FT) ELEV (FT) ELEV (FT) ELEV (FT) DESCRIPTION (FT) DESCRIPTION (FT) DESCRIPTION (FT) DESCRIPTION (FT) POINT POINT POINT POINT STATION STATION STATION STATION 0.00 679575.[PHONE REDACTED].098 33.75 (787)SET REBAR   1316 0 0 0 24.13 679568.[PHONE REDACTED].014 33.64 (270)CREEK TOP 1317 0 24.13 24.13 27.88 679567.[PHONE REDACTED].582 30.78 (268)CREEK TOE 1318 0 27.88 27.88 33.82 679565.[PHONE REDACTED].220 30.63 (256)CREEK CL 1324 0 33.82 33.82 34.31 679565.[PHONE REDACTED].681 31.16 (276)EDGE WATER 1323 0 7:26 34.31 34.86 679565.[PHONE REDACTED].204 30.93 (268)CREEK TOE 1319 0 34.86 34.86 42.94 679562.[PHONE REDACTED].882 31.85 (300)GRADE BRK 1322 0 42.94 42.94 49.12 679560.[PHONE REDACTED].747 33.82 (270)CREEK TOP 1320 0 49.12 49.12 57.01 679558.[PHONE REDACTED].245 33.96 (304)GRND SHOT 1321 0 57.01 57.01 STATION (FT) STATION (FT) STATION (FT) STATION (FT) NORTHING (FT) NORTHING (FT) NORTHING (FT) NORTHING (FT) EASTING (FT) EASTING (FT) EASTING (FT) EASTING (FT) ELEV (FT) ELEV (FT) ELEV (FT) ELEV (FT) DESCRIPTION (FT) DESCRIPTION (FT) DESCRIPTION (FT) DESCRIPTION (FT) POINT POINT POINT POINT STATION STATION STATION STATION 0.00 675136.[PHONE REDACTED].389 217.03 (784)SET PK/SPIKE   1373 0 0 0 3.95 675133.[PHONE REDACTED].222 208.37 (300)GRADE BRK 1382 0 3.95 3.95 7.71 675131.[PHONE REDACTED].937 203.31 (322)RET WALL TOP 1381 0 7.71 7.71 10.64 675129.[PHONE REDACTED].058 203.00 (782)SET HUB/TACK  1372 0 10.64 10.64 12.84 675127.[PHONE REDACTED].649 202.33 (276)EDGE WATER 1379 0 12.84 12.84 14.41 675126.[PHONE REDACTED].780 202.23 (256)CREEK CL 1378 0 14.41 14.41 14.56 675126.[PHONE REDACTED].893 202.57 (276)EDGE WATER 1380 0 14.56 14.56 16.12 675125.[PHONE REDACTED].017 202.32 (276)EDGE WATER 1377 0 16.12 16.12 27.65 675117.[PHONE REDACTED].345 204.01 (332)TOE OF BANK 1376 0 27.65 27.65 32.58 675113.[PHONE REDACTED].909 217.11 (300)GRADE BRK 1375 0 32.58 32.58 36.15 675111.[PHONE REDACTED].540 219.46 (787)SET REBAR   1374 0 36.15 36.15 XS487 (Silver Creek) XS487 (Silver Creek) XS487 (Silver Creek) XS487 (Silver Creek) XS488 (Silver Creek) XS488 (Silver Creek) XS488 (Silver Creek) XS488 (Silver Creek) 25 26 27 28 29 30 31 32 33 34 35 0 10 20 30 40 50 60 Elevation (ft) Station (ft) 200 205 210 215 220 225 0 10 20 30 40 Elevation (ft) Station (ft) Page 17 of18 ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Surveyed Crosssections Appendix B STATION (FT) STATION (FT) STATION (FT) STATION (FT) NORTHING (FT) NORTHING (FT) NORTHING (FT) NORTHING (FT) EASTING (FT) EASTING (FT) EASTING (FT) EASTING (FT) ELEV (FT) ELEV (FT) ELEV (FT) ELEV (FT) DESCRIPTION (FT) DESCRIPTION (FT) DESCRIPTION (FT) DESCRIPTION (FT) POINT POINT POINT POINT STATION STATION STATION STATION 0.00 675276.[PHONE REDACTED].315 188.63 (787)SET REBAR   1390 0 0 0 6.94 675273.[PHONE REDACTED].765 185.86 (270)CREEK TOP 1391 0 6.94 6.94 8.93 675272.[PHONE REDACTED].637 182.95 (268)CREEK TOE 1392 0 8.93 8.93 11.65 675271.[PHONE REDACTED].168 182.87 (256)CREEK CL 1393 0 11.65 11.65 11.92 675271.[PHONE REDACTED].374 183.15 (276)EDGE WATER 1396 0 11.92 11.92 14.98 675271.[PHONE REDACTED].565 183.14 (268)CREEK TOE 1394 0 14.98 14.98 21.65 675269.[PHONE REDACTED].888 188.58 (270)CREEK TOP 1395 0 21.65 21.65 26.71 675269.[PHONE REDACTED].051 192.85 (774)FND REBAR/CAP  BNDY  1389 0 26.71 26.71 XS494 (Silver Creek) XS494 (Silver Creek) XS494 (Silver Creek) XS494 (Silver Creek) 180 182 184 186 188 190 192 194 0 5 10 15 20 25 30 Elevation (ft) Station (ft) Page 18 of18 ---PAGE BREAK--- ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Appendix C: Annotated Stream Profiles ---PAGE BREAK--- This page intentionally left blank. ---PAGE BREAK--- RODY CREEK PROFILE AND GENERAL GEOMORPHIC CONDITIONS Clarks Creek Sediment Reduction Action Plan Profile Vertical Scale: 1 inch = 50 feet, Profile Horizontal Scale: 1 inch = 600 feet Surface Geology from Troost, K.G. in Review, Geologic Map of the Puyallup 7.5 Munite Quadrangle, Washington: U.S. Geologic Survey Mischellaneous Field Investication, Scale 1:24,000 ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ELEVATION (FT) 40 60 80 100 120 140 160 180 200 220 240 260 280 300 320 340 360 380 400 420 STREAM STATION (FT) 2000 1000 3000 4000 5000 6000 7000 8000 9000 RC-R02 RC-R03 RC-R04 RC-R05 RC-R06 RC-R08 RC-R07 RC-R09 RC-R10 STREAM REACH FOR MFA ANALYSIS CONDITION SUMMARY Large sediment production upstream of 72nd from hillslopes and channel Subsequent aggradation of 72nd Moderate incision of 80th St E and upstream of 80th St E RECOMMENDATIONS Channel roughening immediately and upstream of 80th St E using large boulders, wood and streambed gravel mix Sediment source analysis study PIONEER WAY E 72ND ST E 80TH ST E 84TH ST E Qpog Glacial deposits of pre-Olympia age mixed very dense fine- and coarse- grained deposits QVa (Advance Outwash) QVt (Glacial Till) QVr (Recessional Outwash) QVt (Glacial Till) EXISTING STREAM BED PROFILE CULVERT AND DROP STRUCTURE (not to scale, for illustrative purposes only) AGGRADATION MODERATE INCISION MODERATE INCISION APPROXIMATE LOCATION OF LEFT BANK TRIBUTARIES AND HILLSLOPE INSTABILITY XS 468 XS BC13 XS 456 CHANNEL ROUGHENING CHANNEL ROUGHENING 90 95 100 105 110 115 0 20 40 60 80 100 Elevation (ft) Distance (ft) Elevation (ft) 250 260 270 280 290 0 10 20 30 40 50 60 70 80 Distance (ft) 180 200 220 240 260 280 0 20 40 60 80 100 120 140 Distance (ft) Elevation (ft) DRAFT T E T E EXISTING EXISTING STREAM BED STREAM ---PAGE BREAK--- DIRU CREEK PROFILE AND GENERAL GEOMORPHIC CONDITIONS Clarks Creek Sediment Reduction Action Plan ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? Profile Vertical Scale: 1 inch = 50 feet, Profile Horizontal Scale: 1 inch = 600 feet Surface Geology from Troost, K.G. in Review, Geologic Map of the Puyallup 7.5 Munite Quadrangle, Washington: U.S. Geologic Survey Mischellaneous Field Investication, Scale 1:24,000 CONDITION SUMMARY Relatively stable, good conditions Large wood complexes are storing sediment No major hillslope failures RECOMMENDATIONS Monitor cross-sections to evaluate long-term stability and in-channel sediment production Localized bank stabilization using woody plant material PIONEER WAY E 72ND ST E 84TH ST E 80TH ST E 90TH ST E MODERATE BANK EROSION QVr (Recessional Outwash) QVa (Advance Outwash) Qpog Glacial deposits of pre-Olympia age mixed very dense fine- and coarse- grained deposits Qpon Non-glacial deposits of pre-Olympia age (gravel, sand, silt, clay, peat, tephra) Qal (Alluvium) Qf (Fan deposits) QVt (Glacial Till) XS 422 XS 423 XS 430 XS 437 XS 440 EXISTING STREAM BED PROFILE BANK STABILIZATION 49 59 69 0 10 20 30 40 50 60 70 Elevation (ft) Distance (ft) 80 90 100 110 0 20 40 60 80 100 120 Elevation (ft) Distance (ft) 156 166 176 186 0 20 40 60 80 100 Elevation (ft) Distance (ft) 236 246 256 266 0 20 40 60 80 100 Elevation (ft) Distance (ft) 272 282 292 0 20 40 60 80 100 Elevation (ft) Distance (ft) STREAM STATION (FT) 40 60 80 100 120 140 160 180 200 220 240 260 280 300 320 340 360 380 [PHONE REDACTED] 3000 4000 5000 6000 7000 8000 9000 ELEVATION (FT) DC-R02 DC-R03 DC-R04 DC-R05 DC-R06 DC-R07 DC-R08 DC-R09 DC-R10 STREAM REACH FOR MFA ANALYSIS DRAFT ---PAGE BREAK--- WOODLAND CREEK PROFILE AND GENERAL GEOMORPHIC CONDITIONS Clarks Creek Sediment Reduction Action Plan ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? WC-R03 WC-R04 WC-R05 WC-R06 WC-R07 WC-R08 WC-R09 WC-R10 WC-R11 WC-R12 STREAM STATION (FT) 40 3000 2000 4000 5000 6000 7000 8000 9000 10000 60 80 100 120 140 160 180 200 220 240 260 280 300 320 340 360 380 400 420 ELEVATION (FT) STREAM REACH FOR MFA ANALYSIS XS 477 XS BC03 XS BC05 PIONEER WAY E 80TH ST E 84TH ST E 96TH ST E Profile Vertical Scale: 1 inch = 50 feet, Profile Horizontal Scale: 1 inch = 600 feet Surface Geology from Troost, K.G. in Review, Geologic Map of the Puyallup 7.5 Munite Quadrangle, Washington: U.S. Geologic Survey Mischellaneous Field Investication, Scale 1:24,000 EXISTING STREAM BED PROFILE CONDITION SUMMARY degrading channel of 80th St E Large wetland acts as sediment trap Severely incised channel of 84th St E RECOMMENDATIONS Bank and bed stabilization and grade control of 80th (channel restoration) Channel roughening of 84th St E using boulders, wood, and streambed gravel mix BANK AND BED EROSION PERCHED CULVERT AT 80TH STREET SLIGHT INCISION CHANNEL INCISION - CHANNEL RESTORATION CHANNEL ROUGHENING Qal (Alluvium) Qp (Peat Deposits) Qpog Glacial deposits of pre-Olympia age mixed very dense fine- and coarse- grained deposits QVre Recessional Lacustrine Deposits (Note: On right bank side of Woodland Creek, QVre deposits extend through entire stream profile) Steilacoom Gravel QVa (Advance Outwash) QVt (Glacial Till) XS BC01 20 25 30 35 0 5 10 15 20 25 30 35 Elevation (ft) Distance (ft) 100 105 110 0 5 10 15 20 25 Elevation (ft) Distance (ft) 186 191 196 201 206 211 216 0 20 40 60 80 100 120 140 160 Elevation (ft) Distance (ft) 190 195 200 205 210 215 220 0 50 100 150 200 Elevation (ft) Distance (ft) DRAFT ---PAGE BREAK--- UPPER CLARKS CREEK PROFILE AND GENERAL GEOMORPHIC CONDITIONS Clarks Creek Sediment Reduction Action Plan Profile Vertical Scale: 1 inch = 50 feet, Profile Horizontal Scale: 1 inch = 600 feet Surface Geology from Troost, K.G. in Review, Geologic Map of the Puyallup 7.5 Munite Quadrangle, Washington: U.S. Geologic Survey Mischellaneous Field Investication, Scale 1:24,000 ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? STREAM STATION (FT) ELEVATION (FT) 40 60 80 100 120 140 160 180 200 220 240 260 280 300 320 340 360 380 400 420 20000 21000 22000 23000 24000 25000 26000 27000 28000 CC-R16 CC-R17 CC-R18 CC-R21 CC-R22 CC-R23 CC-R24 CC-R25 CC-R19 CC-R20 STREAM REACH FOR MFA ANALYSIS XS 414 XS 399 XS 411 CONDITION SUMMARY Extreme incision and channel degradation of 23rd Ave SW Unstable hill slopes RECOMMENDATIONS Channel roughening using large boulders, wood and streambed gravel mix 23RD AVE SW POND WETLANDS Qpf Sedimentary deposits of pre-Fraser glaciation age (very dense, hard, fine-coarse grained deposits) QVa (Advance Outwash) QVt (Glacial Till) QVre Recessional Lacustrine Deposits Steilacoom Gravel AGGRADATION SEVERE INCISION 20'-40' BANKS FISH HATCHERY DAM INCISION HEADCUT BANK EROSION 20' BANKS EXISTING STREAM BED PROFILE CHANNEL ROUGHENING 76 81 86 91 96 0 20 40 60 80 100 120 Elevation (ft) Distance (ft) 201 211 221 231 0 20 40 60 80 100 120 Elevation (ft) Distance (ft) 86 91 96 101 106 0 50 100 150 200 Elevation (ft) Distance (ft) DRAFT ---PAGE BREAK--- SILVER CREEK PROFILE AND GENERAL GEOMORPHIC CONDITIONS Clarks Creek Sediment Reduction Action Plan Profile Vertical Scale: 1 inch = 50 feet, Profile Horizontal Scale: 1 inch = 600 feet Surface Geology from Troost, K.G. in Review, Geologic Map of the Puyallup 7.5 Munite Quadrangle, Washington: U.S. Geologic Survey Mischellaneous Field Investication, Scale 1:24,000 ? ? ? ? ? ? ? ? ? ? ? ? ? STREAM REACH FOR MFA ANALYSIS STREAM STATION (FT) 5000 6000 7000 8000 9000 4000 3000 2000 1000 SC-R01 SC-R02 SC-R03 SC-R04 SC-R05 SC-R06 SC-R07 SC-R08 SC-R09 40 60 80 100 120 140 160 180 200 220 240 260 280 300 320 340 360 380 400 420 ELEVATION (FT) CONDITION SUMMARY Vertically eroding valley walls near infrastructure Severe channel incision of 23rd Ave SW Slight incision upstream of 15th Ave SW Possible headcut of 15th Ave SW RECOMMENDATIONS Roughen channel of 23rd Ave SW using boulders, wood and streambed gravel mix Channel restoration upstream of 15th Ave SW Investigate potential headcut of 15th Ave SW 12TH AVE SW 15TH AVE SW 19TH AVE SW 96TH ST E/23RD AVE SW Qal (Alluvium) Qp (Peat Deposits) QVre Recessional Lacustrine Deposits Steilacoom Gravel EXISTING STREAM BED PROFILE XS 485 XS 494 AGGRADATION POSSIBLE HEADCUT SLIGHT INCISION MODERATE INCISION AGGRADATION SEVERE INCISION CHANNEL RESTORATION CHANNEL ROUGHENING 115 120 125 135 130 0 10 20 30 40 50 60 70 80 Elevation (ft) Distance (ft) 180 185 190 195 0 5 10 15 20 25 30 Elevation (ft) Distance (ft) DRAFT ---PAGE BREAK--- ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan DRAFT for review purposes only. Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan DRAFT (v15).docx Appendix D: Tetra Tech’s Watershed Modeling Report ---PAGE BREAK--- This page intentionally left blank. ---PAGE BREAK--- Clarks Creek Sediment Study Watershed Model Report Prepared for Puyallup Tribe of Indians Prepared by REVISED DRAFT April 4, 2012 3200 Chapel Hill-Nelson Hwy, Suite 105 • PO Box 14409 Research Triangle Park, NC 27709 ---PAGE BREAK--- ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 i Contents 1 1.1 Clarks 1-1 1.2 Scope of this 1-3 1.3 Project Quality Objectives 1-3 1.4 Model 1-5 2 3 Hydrologic Response Unit Representation 3.1 Soils and 3-1 3.2 Land Use / Land Cover 3-7 3.3 3.4 HRU Numbering 4 Routing Network and 4.1 Surface Drainage Segmentation 4-1 4.2 Reach 4-4 4.2.1 HEC-RAS 4-4 4.2.2 SWMM Modeling 4-5 4.2.3 Other Cross Sections 4-6 4.2.4 WSDOT Flow Splitter 4-6 4.3 Groundwater 4-7 4.4 Stormwater 4-8 5 Model Calibration and Validation Approach 5.1 Acceptance Criteria for Model Calibration 5-1 5.2 Performance Targets for 5-1 6 Hydrologic Calibration and 6.1 Parameter Selection 6-1 6.2 Groundwater Model Setup for Spring 6-4 6.3 Hydrology Model Calibration 6-5 6.4 Hydrology Model Validation 6.5 Simulation of Hourly 6.6 Comparison to Additional Flow Information 7 Sediment Calibration and 7.1 Sediment Calibration Approach 7-1 7.2 Upland Parameter Specification 7-2 ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 ii 7.3 Sediment Transport to 7-4 7.4 Reach Sediment Setup 7-6 7.5 Instream Sediment Calibration 7-7 7.6 Sediment Model 7.7 Sediment Load 7.8 Effective Work 7.9 Sensitivity of Sediment Model 8 Other Water Quality 8.1 Water Quality Model 8-1 8.2 Water Quality Model Results 8-2 9 Natural Condition and Buildout 9.1 Natural Conditions 9-1 9.2 Buildout 9-1 9.3 Scenario Results 9-4 10 References Appendix A. Impervious Area ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 iii List of Tables Table 2-1. Cited Precipitation Data Table 3-1 NRCS Hydrologic Soil Groups in Clarks Creek Table 3-2. Soil Series in the Clarks Creek Watershed Table 5-1. Performance Targets for HSPF Hydrologic Simulation (Magnitude of Annual and Seasonal Relative Mean Error (RE); Daily and Table 5-2. Performance Targets for HSPF Water Quality Simulation (Magnitude of Relative Error (RE) on Daily Table 6-1. Hydrologic Parameter Assignment by Soil Table 6-2. Hydrologic Parameter Assignments by Slope and Soil Table 6-3. Hydrologic Parameter Assignments by Month Table 6-4. Groundwater Model Parameter Estimates for Clarks Table 6-5 Seasonal Summary: Model vs. USGS 12102075 Clarks Creek at Tacoma Road near Puyallup, WA, Calibration Period Table 6-6. Summary Statistics: Model vs. USGS 12102075 Clarks Creek at Tacoma Road near Puyallup, WA, Calibration Period Table 6-7. Seasonal Summary: Model vs. USGS 12102075 Clarks Creek at Tacoma Road near Puyallup, WA, Validation Period Table 6-8. Summary Statistics: Model vs. USGS 12102075 Clarks Creek at Tacoma Road near Puyallup, WA, Validation Period Table 7-1. Sediment Buildup Parameters for Impervious Table 7-2. Calibration Statistics for Total Suspended Sediment, 2002 – 2010 Table 7-3. Validation Statistics for Total Suspended Sediment, 1996 – 2001 Table 7-4. Clarks Creek Sediment Balance for 1960-2010 Simulation Table 7-5. Upland Sediment Load Sources for 1960-2010 Table 7-6. Major Tributary Contributions to Sediment Load to Clarks Creek Table 7-7. Effective Work Analysis for Clarks Creek Table 8-1. Green-Duwamish Loading Rates by Land Use (Herrera, Table 8-2. Green-Duwamish EMCs for Nutrients and Table 8-3. Upland Nutrient and Bacteria Load Sources for 1960-2010 Simulation Table 8-4. Major Tributary Contributions of Nutrient and Bacteria Load to Clarks Creek Table 9-1. HSPF FTable for Representing LID BMP on a Unit Area Basis Table 9-2. Scenario Results for Table 9-3. Scenario Results for Sediment Table 9-4. Change in Effective Work Index from Existing to Buildout ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 iv (This page left intentionally blank.) ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 v List of Figures Figure 1-1. Clarks Creek Watershed Location Map 1-2 Figure 3-1. Surface Hydrogeology of the Clarks Creek Watershed (Savoca et al., 2010) 3-3 Figure 3-2 Soil Series in the Clarks Creek 3-4 Figure 3-3 Hydrologic Soil Groups in the Clarks Creek Watershed 3-5 Figure 3-4. NLCD Land Use/Land Cover for the Clarks Creek Watershed 3-8 Figure 3-5. Crop Data Layer for the Clarks Creek 3-9 Figure 3-6. LANDFIRE Land Cover for the Clarks Creek Watershed 3-10 Figure 3-7 Existing Land Use from Pierce County Tax Parcel Data (3/08) 3-11 Figure 3-8. Distribution of LANDFIRE Canopy Coverage in Forest Areas of Clarks Creek 3-12 Figure 4-1. Monitoring and Gage Locations in Clarks 4-2 Figure 4-2. Subbasin Delineation for Clarks Creek HSPF 4-3 Figure 4-3. HEC-RAS Model and Additional Stream Cross-Section Locations for Clarks Creek 4-5 Figure 4-4. SWMM Model Incorporating Pioneer Avenue Drainage to Clarks 4-6 Figure 4-5. Detail of North-South Section West of Clarks Creek Headwaters (from Savoca et al., 2010, Plate 4-8 Figure 4-6. Interpreted Groundwater Flow in the A1, A3, and C Aquifers in the Vicinity of Clarks Creek (details from Savoca et al., 2010, figures 4-10 Figure 4-7. Longitudinal Profile of Clarks 4-11 Figure 6-1. Comparison of Flow Gaging on Clarks Creek and Clover Creek, 1995-2008...... 6-1 Figure 6-2. Calibrated Fit to Inferred Spring Contribution to Clarks Creek 6-5 Figure 6-3. Mean Daily Flow: Model vs. USGS 12102075 Clarks Creek at Tacoma Road near Puyallup, WA, Calibration Period 6-6 Figure 6-4. Mean Flow: Model vs. USGS 12102075 Clarks Creek at Tacoma Road near Puyallup, WA, Calibration Period 6-6 Figure 6-5. Daily Flow Regression: Model vs. USGS 12102075 Clarks Creek at Tacoma Road near Puyallup, WA, Calibration Period 6-7 Figure 6-6. Flow Regression and Temporal Variation: Model vs. USGS 12102075 Clarks Creek at Tacoma Road near Puyallup, WA, Calibration 6-7 Figure 6-7. Seasonal Regression and Temporal Aggregate: Model vs. USGS 12102075 Clarks Creek at Tacoma Road near Puyallup, WA, Calibration 6-8 Figure 6-8. Seasonal Medians and Ranges: Model vs. USGS 12102075 Clarks Creek at Tacoma Road near Puyallup, WA, Calibration Period 6-8 ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 vi Figure 6-9. Flow Exceedence: Model vs. USGS 12102075 Clarks Creek at Tacoma Road near Puyallup, WA, Calibration 6-9 Figure 6-10 . Flow Accumulation: Model vs. USGS 12102075 Clarks Creek at Tacoma Road near Puyallup, WA, Calibration 6-10 Figure 6-11. Mean Daily Flow: Model vs. USGS 12102075 Clarks Creek at Tacoma Road near Puyallup, WA, Validation Period 6-12 Figure 6-12. Mean Flow: Model vs. USGS 12102075 Clarks Creek at Tacoma Road near Puyallup, WA, Validation Period 6-12 Figure 6-13. Daily Flow Regression: Model vs. USGS 12102075 Clarks Creek at Tacoma Road near Puyallup, WA, Validation Period 6-13 Figure 6-14. Flow Regression and Temporal Variation: Model vs. USGS 12102075 Clarks Creek at Tacoma Road near Puyallup, WA, Validation Period 6-13 Figure 6-15. Seasonal Regression and Temporal Aggregate: Model vs. USGS 12102075 Clarks Creek at Tacoma Road near Puyallup, WA, Validation Period 6-14 Figure 6-16. Seasonal Medians and Ranges: Model vs. USGS 12102075 Clarks Creek at Tacoma Road near Puyallup, WA, Validation Period 6-14 Figure 6-17. Flow Exceedence: Model vs. USGS 12102075 Clarks Creek at Tacoma Road near Puyallup, WA, Validation Period 6-15 Figure 6-18. Flow Accumulation: Model vs. USGS 12102075 Clarks Creek at Tacoma Road near Puyallup, WA, Validation Period 6-15 Figure 6-19. Hourly Flow Prediction for Clarks Creek at Tacoma Rd., Fall 6-16 Figure 6-20. Hourly Flow Prediction for Clarks Creek at Tacoma Rd., Fall 6-17 Figure 6-21. Comparison of Observed and Simulated Flows for Clarks Creek at Mouth and Rody Creek (cfs) 6-18 Figure 6-22. Comparison of Observed and Simulated Flows for Miscellaneous Clarks Creek Measurements 6-19 Figure 6-23. Flow Measurements in Vicinity of State 6-20 Figure 7-1. Average Annual Sediment Yield by Land Use 7-5 Figure 7-2. Example Relationship between Tau and Flow, Reach 7-6 Figure 7-3. Simulated Change in Bed Depth by Model Reach, 7-7 Figure 7-4. Time Series Comparison for TSS, Clarks Creek above State Hatchery, 2002-2010 7-8 Figure 7-5. Time Series Comparison for TSS, Clarks Creek below State Hatchery, 7-8 Figure 7-6. Time Series Comparison for TSS, Clarks Creek at 12th St. Bridge, 2002-2010 7-9 Figure 7-7. Time Series Comparison for TSS, Clarks Creek above 7th Street, 2002-2010 7-9 ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 vii Figure 7-8. Time Series Comparison for TSS Calibration, Clarks Creek at 66th Street, 7-10 Figure 7-9. Power Plots of TSS Load and Concentration versus Flow, Clarks Creek at 66th Street, 2002-2010 7-11 Figure 7-10. TSS Prediction Error versus Month, Clarks Creek at 66th Street, 2002-2010. 7-11 Figure 7-11. TSS Prediction Error versus Flow, Clarks Creek at 66th Street, 2002-2010 7-12 Figure 7-12. Hourly Variability in Predicted Sediment Concentration, Clarks Creek at 66th Street, December 7-12 Figure 7-13. Mainstem Reaches, Clarks 7-18 Figure 7-14. Longitudinal Profile of Effective Work Index 7-20 Figure 7-15. Effective Work Curves for Reaches in the Till Area, Existing 7-20 Figure 8-1. Nutrient and Bacterial Loads by Tributary to Clarks Creek 8-4 Figure 9-1. Current and Future Buildout Land Uses in Clarks Creek 9-1 Figure 9-2. BMP Representation of LID Performance Standard for New Development........ 9-3 Figure 9-3. Flow Durations for Clarks Creek at 66th St. under Current, Natural, and Buildout 9-5 ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 viii (This page left intentionally blank.) ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 1-1 1 Introduction 1.1 CLARKS CREEK The Clarks Creek watershed is located in the lower Puyallup River Basin, not far from Commencement Bay (southern end of Puget Sound) and the northwest corner of Pierce County, WA (Figure 1-1). It is within Washington Department of Ecology’s Water Resources Inventory Area (WRIA) 10. The Clarks Creek watershed area is divided between the City of Puyallup and unincorporated areas of Pierce County. The most northern portion of the watershed is within the Puyallup Tribal Reservation. The surface drainage occupies an area of 10.4 square miles of glacial deposits, foothill ridges, and flat valley land along the Puyallup River. Additional groundwater flow in Clarks Creek is derived from portions of an internally drained area to the south and east of the surface drainage network, known as the Potholes region. The headwaters of the Clarks Creek surface drainage network start approximately one- third of a mile south of Maplewood Springs and flow 3.6 miles through Pierce County, the City of Puyallup, and Puyallup Tribal lands before discharging into the Puyallup River. The surficial geology of the Clarks Creek area is a product of glaciations and subsequent alluvial processes (Jones et al., 1999). The headwaters of the Clarks Creek drainage are primarily in the Vashon recessional till. From there, the creek descends for a few miles through the upper aquifer unit before transitioning to alluvial soils in the Puyallup River valley. The highly permeable surface aquifers of upper Clarks Creek result in substantial exchanges between the surface and ground water systems (Savoca et al., 2010). Groundwater movement in the surface aquifer (Vashon recessional till or A1 aquifer) generally follows the land surface gradient, with seeps and springs where this layer thins out, as at Maplewood Springs, which forms the headwaters of Clarks Creek. The USGS is in the process of creating a regional groundwater model, and the initial framework report (Savoca et al., 2010) suggests that water in the A1 aquifer may flow to Maplewood Springs from a distance of up to five miles or more from the south and east. ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 1-2 Figure 1-1. Clarks Creek Watershed Location Map Rody Creek City of Puyallup State Route 512 Pacific Ave Pacific Hwy 11th St State Route 167 Meridian Ave Schuster Pky Enchanted Pky River Rd I-5 Puyallup River Swam Creek Clear Creek Clarks Creek Hylebos Creek N. Fork Clover Creek Tacoma Clarks Creek Watershed CANADA Washington Oregon Clarks Creek Watershed Location Map Map produced by P. Cada - 11-29-2010 NAD_1983_HARN_StatePlane_Washington_South_FIPS_4602_Feet 0 2 4 1 Kilometers 0 2 4 1 Miles Legend Maplewood Springs Major Streams Major Roads Tacoma City of Puyallup 1873 Tribal Survey Area Clarks Creek Watershed Commencement Bay Pierce Co. King Co. ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 1-3 1.2 SCOPE OF THIS REPORT The Puyallup Tribe of Indians (PTI) has been working for many years to improve water quality in Clarks Creek. As part of this effort, PTI received an EPA-funded grant entitled “Reducing Effective Impervious Surfaces in a Small Urban Catchment Using LID Practices.” The overall contract to support work under this grant was issued to Brown and Caldwell, while Tetra Tech was issued a companion work assignment to support watershed modeling. The watershed model focuses on flow and sediment loading in the watershed. Excess sediment loading contributes to a variety of water quality problems in Clarks Creek. Notably, fine sediment accumulation is an important factor in promoting dense growths of the nuisance waterweed elodea that adversely impact DO concentrations, in turn threatening salmonid success, and clog the Tribe’s hatchery intakes. Sediment loads may also contain elevated nutrient concentrations that promote macrophyte growth, as well as elevated fecal coliform bacteria concentrations that can contribute to impairment of uses. The overall goal of the project is to improve water quality in Clarks Creek by reducing sediment load. To accomplish this, the following objectives must be met: 1. Sediment sources must be identified and characterized. 2. Sediment pathways to Clarks Creek must be understood. 3. Anthropogenic elements of sediment load must be understood. 4. Methods to reduce the anthropogenic sediment load must be developed and implemented. The Clarks Creek watershed model is a tool to assist in evaluating the relationship between sediment sources, urban stormwater, and conditions within Clarks Creek. This report documents the development, calibration, and validation of the watershed model. Following review and approval of the model, the tool can be used to aid in the selection of management efforts to protect and restore Clarks Creek. 1.3 PROJECT QUALITY OBJECTIVES Environmental simulation models are simplified mathematical representations of complex real world systems. Models cannot accurately depict every one of the multitude of processes occurring at all physical and temporal scales in a watershed. Models can, however, make use of known interrelationships among variables to predict how a given quantity or variable would change in response to a change in an interdependent variable or forcing function. In this way, models can be useful frameworks for investigations of how a system would likely respond to a perturbation from its current state. To provide a credible basis for prediction and the evaluation of mitigation options, the ability of the model to represent real world conditions should be demonstrated through a process of model calibration and corroboration or validation. USEPA (2002) recommends following a systematic planning process to define quality objectives and performance criteria. For modeling projects, systematic planning identifies the expected outcome of the modeling, its technical goals, cost and schedule, and the criteria for determining whether the inputs and outputs of the various intermediate stages of the project, as well as the project’s final product, are acceptable. The systematic planning approach begins with identifying Principal Study Questions, and designs the modeling effort to answer these questions. This process is described in the modeling Quality Assurance Project Plan (QAPP; Tetra Tech, 2011). Principal Study Questions A detailed description of water quality and use assessment in Clarks Creek by Washington Department of Ecology, along with information on land use, geology, vegetation, and other watershed characteristics is provided in the Clarks Creek Data Review (Tetra Tech, 2010) conducted for USEPA Region 10 in ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 1-4 support of the Clarks Creek Dissolved Oxygen (DO) TMDL. Depressed DO in Clarks Creek occurs as the net result of a series of complex processes. Excess sediment loading contributes in a variety of ways to the DO problems in Clarks Creek. Notably, fine sediment accumulation is an important factor in promoting dense growths of elodea that adversely impact DO concentrations both directly, through diurnal respiration, and indirectly through contributions to SOD. Elodea growth in turn slows flows in the creek, which reinforces sediment deposition and accumulation and leads to flooding problems. Sediment loads may also contain elevated nutrient concentrations that promote macrophyte growth, as well as elevated bacterial concentrations. In addition to use assessments conducted by Ecology, fisheries stakeholders (including the Puyallup Tribe) have an interest in reducing geomorphically significant flows that could result in salmon redd scour or burial and reduced juvenile salmon survival. The Puyallup Tribe is also interested in reducing channel erosion. In sum, the Principal Study Questions to be addressed by modeling in this project are: 1. What are the principal sources of sediment load in the Clarks Creek watershed? 2. How are sediment loads in the watershed transported to Clarks Creek? 3. What is the significance of sources of instream generation of sediment load due to scour and bank failure and what factors control these loads? 4. What is the optimal selection of management measures to reduce both the anthropogenic sediment load and excess flows that promote instream generation of sediment load via channel degradation? Identify the Decision The intended end product of this work is the development of a sediment management plan for Clarks Creek. The watershed simulation model should provide the ability to evaluate the relative benefit of different management alternatives that may control upland sediment loads and the occurrence of flows that cause channel scour with subsequent deposition in the lower reaches of Clarks Creek. Identify the Inputs to the Decision The watershed model developed as a result of this TO will be used to evaluate a variety of potential management scenarios (to be developed by Brown and Caldwell). The model provides decision-related inputs on the impacts of these scenarios on total sediment load to Clarks Creek from both upland and instream sources and anticipated rates of sediment deposition within Clarks Creek. Develop a Decision Rule for Information The purpose of a decision rule is to integrate the outputs from the study into a single statement that describes the logical basis for choosing among alternative actions. Output from the previous steps will be used to guide decision makers in efforts to choose from alternative actions. The model is applied in the context of a larger stakeholder process and management scenario development being conducted by Brown and Caldwell for PTI. The overall decision rule relative to the watershed model is: To support uses in Clarks Creek it is necessary to control a variety of factors that contribute – directly or indirectly – to elevated sedimentation in the creek. A watershed model that is capable of evaluating flow, upland sediment sources, and instream sediment processes will be used to evaluate the contributions of different sources to current sedimentation conditions and to determine load reductions necessary to achieve standards. The evaluation of the sensitivity and importance of different stressor sources will be used to identify, evaluate, and test potential implementation strategies to reduce sedimentation in Clarks Creek. The modeling will be used to provide evaluations of the potential benefits of candidate management strategies that will be developed by Brown and Caldwell in consultation with PTI and other stakeholders. ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 1-5 Specify Tolerance Limits on Decision Errors To help guide the interpretation of the technical information provided by the water quality model, general performance targets for the modeling are described in Section 5. The performance targets are based on generally accepted values from the literature and experience with previous projects. Specific numeric acceptance criteria cutoffs are not specified for the model. 1.4 MODEL SELECTION Addressing the principal study questions requires a modeling framework that can provide a dynamic simulation of flow, upland sediment loading, and instream sediment transport processes. The Hydrologic Simulation Program – FORTRAN (HSPF) model (Bicknell et al., 2005) was selected for this purpose for several reasons: 1. HSPF provides dynamic simulation of water and sediment, including both upland and instream sediment processes at a user-specified level of detail and complexity, and is thus suitable for addressing the principle study questions. 2. HSPF models have previously been developed to address storm flows in Clarks Creek (Mastin, 1995, CH2MHill, 2003, Pierce Co., 2009). While these models are not fully calibrated for hydrology and have not yet been developed for water quality simulation, they provide a basis for additional development of the current HSPF model. 3. HSPF is supported by EPA with open source code and has a long history of well-documented applications for addressing hydrology and sediment management applications. It also provides a platform for full simulation of nutrients, bacteria, and other endpoints of potential interest. ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 1-6 (This page intentionally left blank.) ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 2-1 2 Meteorology HSPF requires input time series of precipitation and potential evapotranspiration (PET) at a minimum. For the simulation of water and sediment only other meteorological series such as solar radiation and humidity are not required. Air temperature is needed for hydrologic simulations only if snowmelt is simulated. As snowfall is rare in Clarks Creek watershed temperature was not needed. Meteorological time series for Clarks Creek have been assembled over time for a variety of projects. A long period of record is desirable for evaluation of a wide range of potential conditions, and data series assembled for October 1948 through March 2010 were provided by Brown and Caldwell in an HSPF water data management (WDM) file. As described by Doten (2011) these data came from a variety of sources. Data through September 1999 were previously assembled for the City of Puyallup State Highway Basin Plan simulation modeling conducted by Brown and Caldwell and originally assembled by NHC for the Clear and Canyon Creeks Flood Insurance Mapping Study in 2003. Brown and Caldwell extended these data through March of 2010 primarily through use of data collected at the AgNet weather station at Washington State University, Puyallup Campus. This station, located in the center of the Clarks Creek watershed, commenced operation in 1995 but has many data gaps prior to September 1999. Tetra Tech subsequently extended the time series through December of 2010, using data obtained directly from the AgNet site. Prior to the WSU AgNet site coming online, much of the precipitation data was obtained from McMillin Reservoir (Cooperate ID 455224), which reports both hourly and 15-minute precipitation. The precipitation data sources are shown in Table 2-1. Table 2-1. Cited Precipitation Data Sources Time Period Source Oct. 1949 – Sept. 1961 Seattle-Tacoma International Airport Oct. 1961 – Nov. 1980 McMillin Reservoir Dec. 1980 – Nov. 1985 Seattle-Tacoma International Airport Dec. 1985 – Sept. 1989 McMillin Reservoir Oct. 1989 – Sept. 1992 Canyon Road Oct. 1992 – Sept. 1999 McMillin Reservoir Oct. 1999 – Dec. 2010 WSU Puyallup AgNet Doten (2011) notes certain problems with the earlier data assembled by NHC (2003). Most of the data are reported at intervals of hundredths of an inch, but the data from 3/31/1977 – 11/30/1980 and 11/30/1985 – 9/30/1989 are at a much coarser resolution of tenths of an inch. It is also believed that NHC replaced some of the McMillin Reservoir data for 1990-1994 due to poor quality. Further, only summary of the day results are available from McMillin for October 1996 to April 1998, and data from this period were likely disaggregated, although this is not explained in the modeling documentation. Data commencing in October 1999 are believed to be much more accurate, and also are from within the watershed. Doten (2011) documents filling 11 brief periods of missing data using King County rain gauges. ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 2-2 For evapotranspiration, the WSU Puyallup station reports daily actual evapotranspiration (ETr) from alfalfa grown under controlled conditions. The NHC weather data set through 1999 purports to include PET derived from pan evaporation data from Puyallup multiplied by a factor of 0.75 (a standard factor to relate pan evaporation, which is influenced by heating of the exposed sides and bottom of the pan, to potential evaporation from crops) – although it appears that the full set of data may be derived from multiple sources and estimation methods. For the period beginning in October 1999, Brown and Caldwell created daily PET series from the Puyallup reported ETr, divided by 0.85 to get pan evaporation, and then multiplied by 0.75 to get PET. Doten (2011) demonstrates that the resulting PET estimates are generally consistent with the historical data, although it appears that average PET for August – December is lower for the estimates based on ETr from WSU. It is important to note that meteorological data through Sept. 1999 have been accepted from earlier work without revision or detailed quality checks. The data from 1999 on clearly have a higher degree of internal consistency and reliability. ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 3-1 3 Hydrologic Response Unit Representation This section describes the representation of upland land areas in the HSPF model for the Clarks Creek sediment reduction project. HSPF is a lumped model. That is, the land surface is not simulated as an explicit grid. Rather, similar components of the land surface are simulated on a unit-area basis, and the unit-area results are then multiplied by the relevant area to estimate the outflow from a subbasin to a stream reach. These land surface components should be defined in a way that facilitates both parameter identification and the evaluation of management alternatives. In general, this is best accomplished by using a Hydrologic Response Unit (HRU) approach, in which upland model areas are defined on the basis of an overlay and unique combination of soil characteristics, slope, and land use/land cover. The previous HSPF models that cover part or all of Clarks Creek use an HRU approach that was developed for the original USGS model of the Clover Creek and Clear-Clarks Creek basins (Mastin, 1996). This employed a fairly simple classification in which an HRU represented a soil group (till, outwash, or saturated area), a land cover group (forest or grass only for pervious areas), and a slope class (flat, medium, or steep). The steepness classification was applied only to the till areas, while the saturated areas are not subdivided by either land cover or slope. Significant amounts of additional spatial data have become available since the USGS model was developed, allowing refinement of the USGS approach. In addition, the simplified representation of land cover used by Mastin for evaluating sediment sources to Clarks Creek did not consider land use (as opposed to cover), which can be an important factor in determining sediment load. For instance, agricultural land uses typically have higher sediment loading rates than lawns on similar soils and slopes. For these reasons, it is appropriate to develop a revised HRU approach. The following sections describe the key inputs (geology and soils, land use/land cover, slopes), followed by the final HRU definition (Section 3.4). 3.1 SOILS AND GEOLOGY The soil series in the watershed largely reflect the surficial geology. Both are important to the model: the soils largely control infiltration rates and erodibility, while the underlying hydrogeology controls groundwater interactions. A dominant feature of the watershed is the presence of headwater springs on the Clarks Creek mainstem which occur where the overlying Vashon recessional till and outwash tails out onto lower lying alluvial soils. Two recent USGS reports build a picture of the hydrogeology of the watershed that can be used to complement the soil surveys. Jones et al. (1999) provide an initial account. This has been superseded by Savoca et al. (2010). Savoca et al. use a rather different nomenclature, but maintain the basic distinction between the glacial uplands and lower outwash/alluvial plain. The hydrogeological conceptual framework of Savoca et al. is shown in Figure 3-1. The surface hydrogeology of the higher elevation areas of the Clarks Creek watershed is referred to by Savoca et al. as the A1 aquifer (Jones’ Qvr; the Vashon recessional outwash) and the lower permeability A2 unit (Jones’ Qvt; the Vashon recessional till), both of which are underlain by the C or sea-level sand and gravel aquifer (Jones’ Qc1), while the lower elevations of the stream are atop the AL alluvial aquifer (corresponds to Jones’ Qc1 aquifer and Qf1 semi-confining unit). The soil series boundaries conform to the major division of till versus alluvial hydrogeologic units. Soil data were obtained from the NRCS’s SSURGO database via the USDA Data Gateway. As shown in Figure 3-2 and Figure 3-3, soils in the watershed are dominated by Alderwood gravelly sandy loam, Kitsap silt loam, Kapowsin gravelly loam, and Puyallup fine sandy loam. Most of these soils were ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 3-2 formed in consolidated glacial till (hardpan) and typically yield lower infiltration rates, although they may include an overlay of well-drained outwash sands and gravel. NRCS (2001) has defined four Hydrologic Soil Groups (HSGs; Table 3-1). The hydrologic soil group classification provides a means for grouping soils by similar infiltration and runoff characteristics for model parameterization. Typically, clay soils that are poorly drained have lower infiltration rates, while well-drained sandy soils have the greatest infiltration rates. The dominant HSG in the watershed is group C, soils with slow infiltration rates, which covers half of the watershed area. Table 3-1 NRCS Hydrologic Soil Groups in Clarks Creek Watershed Hydrologic Soil Group Description Percentage of Clarks Creek Watershed A Soils with high infiltrations rates. Usually deep, well-drained sands or gravels. Little runoff. 7% B Soils with moderate infiltration rates. Usually moderately deep, moderately well-drained soils. 22% C Soils with slow infiltration rates. Soils with finer textures and slow water movement. 50% D Soils with very slow infiltration rates. Soils with high clay content and poor drainage. High amounts of runoff. 21% ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 3-3 Figure 3-1. Surface Hydrogeology of the Clarks Creek Watershed (Savoca et al., 2010) Clarks Creek Watershed Surface Hydrogeology From Savoca et al., 2010 NAD_1983_HARN_StatePlane_Washington_South_FIPS_4602_Feet 0 0.8 1.6 0.4 Kilometers 0 0.8 1.6 0.4 Miles ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 3-4 Figure 3-2 Soil Series in the Clarks Creek Watershed Clarks Creek Watershed Soils Map - Map Unit Name Map produced by P. Cada, 05-20-2011 NAD_1983_HARN_StatePlane_Washington_South_FIPS_4602_Feet 0 0.8 1.6 0.4 Kilometers 0 0.8 1.6 0.4 Miles Legend Major Streams Major Roads Clarks Creek Watershed Map Unit Name Alderwood gravelly sandy loam Bellingham silty clay loam Briscot loam Dupont muck Everett gravelly sandy loam Indianola loamy sand Kapowsin gravelly loam Kitsap silt loam Neilton gravelly loamy sand Norma fine sandy loam Pilchuck fine sand Pits Puyallup fine sandy loam Semiahmoo muck Shalcar muck Snohomish silty clay loam Sultan silt loam Tisch silt Water Xerochrepts Xerorthents, fill areas ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 3-5 Figure 3-3 Hydrologic Soil Groups in the Clarks Creek Watershed Clarks Creek Watershed Soils Map - Map Unit Name Map produced by P. Cada, 05-20-2011 NAD_1983_HARN_StatePlane_Washington_South_FIPS_4602_Feet 0 0.8 1.6 0.4 Kilometers 0 0.8 1.6 0.4 Miles Legend Major Streams Major Roads Clarks Creek Watershed Hydrologic Soil Group Not Rated A B C D ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 3-6 The Kapowsin-type soils have the lowest infiltration rates in the watershed (HSG while the Alderwood and Kitsap soils are more moderately drained (HSG C; see Table 3-2). The Puyallup loam, which was formed in alluvium and located along the Puyallup River Basin valley portion of the watershed, is classified as well-drained (HSG Several wetland areas exist in the southern headwaters of the watershed due to perched water tables and poor soil infiltration rates common in that area. Table 3-2. Soil Series in the Clarks Creek Watershed HSG Soil Series Area (acres) Percentage Water 4.6 0.07% A Everett gravelly sandy loam 287.4 4.32% Indianola loamy sand 135.4 2.03% Neilton gravelly loamy sand 3.1 0.05% Pits 19.5 0.29% B Puyallup fine sandy loam 1,346.60 20.22% Xerochrepts 107.7 1.62% C Alderwood gravelly sandy loam 1,552.30 23.31% Briscot loam 132.7 1.99% Kitsap silt loam 1,332.50 20.01% Pilchuck fine sand 0.3 0.00% Semiahmoo muck 2.7 0.04% Sultan silt loam 317.6 4.77% D Bellingham silty clay loam 25.8 0.39% Dupont muck 26.9 0.40% Kapowsin gravelly loam 1,141.10 17.14% Norma fine sandy loam 0.5 0.01% Shalcar muck 202 3.03% Snohomish silty clay loam 3.7 0.06% Tisch silt 11 0.17% Xerorthents, fill areas 5.4 0.08% Grand Total 6,658.7 ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 3-7 The Mastin (1996) model separately identified saturated areas based on soil characteristics – although the category was not restricted to specifically hydric soils. These delineations do not seem to be strongly correlated with the extent of wetland areas and may be of limited use due to extensive alteration of the watershed by development and drainage. Therefore, it is more useful to identify as a separate class extant wetlands based on the Pierce County wetlands coverage. In sum, the soils/geology component of the revised HRU classification of pervious area is as follows: 1. Till, high permeability (HSG A with some B) 2. Till, moderate permeability (HSG C) 3. Till, low permeability (HSG D) 4. Alluvial outwash soils (HSG A,B – predominantly B) 5. Alluvial outwash soils (HSG C,D – predominantly C) 0. Wetlands 3.2 LAND USE / LAND COVER The Clarks Creek watershed (as defined by the surface drainage) occupies an area of 6,631 acres, much of which is developed land in and adjacent to the City of Puyallup, WA. Hydrologic and pollutant generating characteristics of pervious lands are determined by both the land use and the vegetative land cover. While the two categories are highly correlated a land cover of pumpkins is likely to be an agricultural land use) they convey different information grass on the edge of a highway is more likely to be subject to disturbance by vehicles and less likely to be fertilized than grass on a residential lawn). In general, satellite coverages yield land cover, while parcel and tax data yield additional information on land use. Many new sources are available for both land cover and land use in the Clarks Creek watershed. Satellite-based land cover is available from the National Land Cover Dataset (NLCD; available for 1991, 2001, and 2006); the Crop Data Layer (CDL) from U.S. Department of Agriculture - National Agricultural Statistics Service, Research and Development Division (available from 2006-2007, and 2009-2010 for Washington); and the LANDFIRE coverage from USFS (2001 and 2008) (Figure 3-4 through Figure 3-6). Parcel-based land use is available in a spatial coverage from Pierce County (Figure 3-7). ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 3-8 Figure 3-4. NLCD Land Use/Land Cover for the Clarks Creek Watershed Clarks Creek Watershed Land Use/Land Cover (NLCD, 2006) Map produced by P. Cada, 05-20-2011 NAD_1983_HARN_StatePlane_Washington_South_FIPS_4602_Feet 0 0.8 1.6 0.4 Kilometers 0 0.8 1.6 0.4 Miles Legend Clarks Creek Watershed Land Use/Land Cover Open water Ice/Snow Developed, open space Developed, low intensity Developed, medium intensity Developed, high intensity Barren land Deciduous forest Evergreen forest Mixed forest Scrub/shrub Grassland/herbaceous Pasture/hay Cultivated crops Woody wetlands Emergent herbaceous wetlands ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 3-9 Figure 3-5. Crop Data Layer for the Clarks Creek Watershed Clarks Creek Watershed Land Use/Land Cover (CDL, 2010) Map produced by P. Cada, 05-20-2011 NAD_1983_HARN_StatePlane_Washington_South_FIPS_4602_Feet 0 0.8 1.6 0.4 Kilometers 0 0.8 1.6 0.4 Miles Legend Clarks Creek Watershed Land Use/Land Cover Barren Blueberries Cabbage Caneberries Christmas Trees Corn Deciduous Forest Developed/High Intensity Developed/Low Intensity Developed/Medium Intensity Developed/Open Space Evergreen Forest Fallow/Idle Cropland Grassland Herbaceous Herbaceous Wetlands Herbs Lettuce Mixed Forest Open Water Pasture/Hay Pumpkins Radishes Shrubland Sod/Grass Seed Squash Strawberries Sweet Corn Triticale Woody Wetlands ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 3-10 Figure 3-6. LANDFIRE Land Cover for the Clarks Creek Watershed Clarks Creek Watershed Land Cover (Landfire, 2008) Map produced by P. Cada, 05-20-2011 NAD_1983_HARN_StatePlane_Washington_South_FIPS_4602_Feet 0 0.8 1.6 0.4 Kilometers 0 0.8 1.6 0.4 Miles Legend Clarks Creek Watershed Landfire Land Cover Barren Cultivated Crops Developed - High Intensity Developed - Medium Intensity Developed-Roads Developed-Upland Deciduous Forest Developed-Upland Evergreen Forest Developed-Upland Herbaceous Developed-Upland Mixed Forest Developed-Upland Shrubland Herb Cover 10 and < 20% Herb Cover 20 and < 30% Herb Cover 30 and < 40% Herb Cover 40 and < 50% Herb Cover 50 and < 60% Herb Cover 60 and < 70% Herb Cover 70 and < 80% Herb Cover 80 and < 90% Herbaceous Semi-dry Herbaceous Wetlands NASS-Close Grown Crop NASS-Orchard NASS-Pasture and Hayland NASS-Row Crop NASS-Row Crop-Close Grown Crop Open Water Pasture/Hay Quarries-Strip Mines-Gravel Pits Recently Disturbed Forest Shrub Cover 10 and < 20% Shrub Cover 20 and < 30% Shrub Cover 30 and < 40% Shrub Cover 40 and < 50% Shrub Cover 50 and < 60% Shrub Cover 60 and < 70% Snow/Ice Sparse Vegetation Canopy Tree Cover 10 and < 20% Tree Cover 20 and < 30% Tree Cover 30 and < 40% Tree Cover 40 and < 50% Tree Cover 50 and < 60% Tree Cover 60 and < 70% Tree Cover 70 and < 80% Tree Cover 80 and < 90% Tree Cover 90 and 100% ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 3-11 Figure 3-7 Existing Land Use from Pierce County Tax Parcel Data (3/08) DeCoursey Park Clarks Creek Park Maplewood Springs State Fish Hatchery WSU Extension Office Clarks Creek Watershed Existing Landuse Map Map produced by P. Cada, 05-20-2011 NAD_1983_HARN_StatePlane_Washington_South_FIPS_4602_Feet 0 0.8 1.6 0.4 Kilometers Legend Major Streams Roads Puyallup City Limits Clarks Creek Watershed Landuse - Pierce County Commercial/Service Education Group Quarters/Other Industrial Mobile Homes Multi-Family Residential Open Space/Recreation Public Facilities Quasi-Public Facilities Residential Outbuildings Resource Land Single-Family Residential Transportation, Communication, Utilities Unknown Vacant Water Bodies 512 River Rd. E. Meridian E. Pioneer Ave. Stewart Ave. Tacoma Rd. Puyallup Tribe Salmon Hatchery 0 0.8 1.6 0.4 Miles ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 3-12 Each of these coverages was created for different purposes, and each has its advantages and disadvantages. For instance, the CDL is available yearly and gives high resolution on crop type, but does not separately distinguish roads. LANDFIRE identifies roads and gives details on tree canopy coverage (important to erosion estimation; see Figure 3-8), but does not identify specific agricultural or developed land uses, which are revealed more clearly by the Pierce County parcel-based coverage (Figure 3-7). Figure 3-8. Distribution of LANDFIRE Canopy Coverage in Forest Areas of Clarks Creek Combining the various sources of land use and land cover data provides the most useful basis for HRU determination. These data sources have been selected to account for potentially significant differences in hydrologic behavior and/or sediment load generation. The land categories developed from combining the land use and land cover data are as follows (with the numbering reflecting the scheme for pervious surfaces): 1. Forest (Tree canopy coverage > 70 percent and not within developed parcels < 1 ac) 2. Forest (Tree canopy coverage 40 – 70 percent, and not within developed parcels < 1 ac) 3. Agriculture – row crop 4. Pasture, hay, close grown crops 5. High density development (commercial, industrial, multi-family) 6. Medium density residential (1/8 - 1 ac/DU) 7. Low density single family residential 1 ac/DU) 8. Roads (right of way not contained within tax parcels) 9. Park and institutional land (exclusive of forest cover in categories 1 and 2, but including any miscellaneous land that does not fit into categories 1 through As noted above, wetlands are separately defined as a unique HRU category as well (with LULC code Extent of canopy coverage is included in the HRU definitions because canopy protection from rainfall impact is an important factor in determining soil erosion, as well as affecting hydrology. The 70 percent breakpoint approximates the cover factor breakpoint of 75 percent for high cover in woodlands used in the Universal Soil Loss Equation (USLE). Below 40 percent canopy cover, the USLE cover factor for forest becomes similar to that for pasture and idle land. 10-20% Canopy 20-30% Canopy 30-40% Canopy 40-50% Canopy 50-60% Canopy 60-70% Canopy 70-80% Canopy 80-90% Canopy Proportion of Tree Canopy Coverage ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 3-13 Forest cover is separated out of larger residential lots 1 ac/DU) to account for the protection of forest cover against erosion. Separating forest is not feasible for smaller lots, as the 30-m resolution of the LANDFIRE coverage cannot effectively distinguish land cover fractions within a lot size of 1 acre or less. Pervious land use within residential land use categories having lot sizes of 1 acre or less and within the non-forest portion of larger residential lots are represented as having a typical land cover of grass with shrubs and scattered trees. The methods developed by Tetra Tech for combining the LANDFIRE, NLCD, CDL, and Pierce Co. parcel datasets into the 9 land use categories in the model are illustrated in Figure 9. LANDFIRE serves as the base coverage for areas that are classified as forest, agriculture, or pasture/hay, including fragments within residential lots greater than 1 acre in size. Residential, commercial, industrial, institutional, and park lands are classified primarily by the county land use data, after subtracting areas identified as forest, agricultural, or pasture/hay in larger parcels. Figure 9. Methods for Combining LANDFIRE, NLCD and CDL Data Sets for Land Use/Land Cover Definition of HRUs The remaining step of land use/land cover development for the model is the separation of impervious and pervious surfaces. HSPF models pervious areas and impervious areas separately because of their different hydrologic behavior. Properly, the area assigned to should be the directly connected (or effective) impervious area; impervious areas that drain onto pervious lands are typically incorporated within the PERLND representation. Impervious surface planimetrics are not available for Pierce County (and would not show the directly connected impervious area in any case). Therefore, impervious area contained within land categories 5 through 9 are assigned on a percentage basis. The proportioning of roads (Category 8) into pervious and impervious surfaces was also adjusted by inspection of recent aerial imagery throughout the watershed. Details of the determination of directly connected impervious area are addressed in a separate Amalgamation of remaining LANDFIRE data and Pierce County land use Data1 Pasture/Hay/Small Grains (based on 2007 CDL and NLCD 2006 data) “Tree Cover with 40-70% Canopy Coverage (Excluding Developed Parcels <1 acre in size) “Tree Cover” with >=70% Canopy Coverage (Excluding Developed Parcels <1 acre in size) Land Category #1 Land Category #2 Agricultural/Row Crops (based on 2007 CDL data) Land Category #3 Land Category #4 Land Categories #5 - 7 and 9 Roadways (Areas not covered by Pierce Co. LUdata) LandCategory #8 PierceCounty Land Use Data (2008) LANDFIRELand Cover Data (2008) ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 3-14 memorandum included as Appendix A. Overall, about 25 percent of the watershed is occupied by directly connected impervious area. are numbered separately from in HSPF. Nonetheless, the same numbering scheme is retained for as is used for for ease in reassembling total flow and loads from specific land uses. Thus, PERLND 611 and 611 refer to the pervious and impervious portions, respectively, of medium density development on A or B till soils on low slopes. 3.3 SLOPE Subdivision of HRUs by slope is useful for sediment simulation as slope is a factor that determines the velocity of flow, its kinetic energy, and the associated transport of detached sediment and/or initiation of gully formation. Mastin’s (1996) approach of identifying three slope classes that correspond to the soil- slope associations is adequate, but can be refined through a DEM-based analysis of slope. The higher slope classes are found primarily on the till portion of the watershed. The three classes are: 1. Low slope 2. Medium slope (6-12%) 3. High slope 3.4 HRU NUMBERING The soil, land/use cover, and slope components of the pervious land HRUs each have less than nine classes. For Clarks Creek a single weather station is used and the PERLND HRUs can be numbered in a straightforward fashion as abc, a three-digit number, where a is the land use category, b is the soil category, and c is the slope category. The land use category is given first so that all members of a given land use are grouped together, which is advantageous for the development of management scenarios. HRUs can be sorted on the second digit for specification of hydrologic parameters that are primarily dependent on soil characteristics. There are a total of 9 land use x 4 soil groups x 3 slope potential HRU categories (plus the unique wetland category). However, wetlands are not distinguished by soil or slope and only low slopes coincide with the alluvial soils, leaving a total of 122 PERLND HRUs that are actually simulated in the model. As noted above, the numbering scheme for HRUs is matched to that of the corresponding PERLND HRU, allowing ready reconstruction of total pervious and impervious surface flows and loads from a single parent land use. This applies to categories 511 and higher. ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 4-1 4 Routing Network and Segmentation The HSPF model consists of upland subbasins and waterbody reaches. In most cases there is a one-to- one match between reach segments and subbasins. Model segmentation first should accurately reflect the surface drainage network. Additional considerations for model segmentation include the following:  Reach segment breaks should coincide with gage and monitoring locations  Significant inflows should coincide with breaks in the reach segments  Different upland subbasins are used to define areas associated with different weather records  Upland subbasin should be sufficiently small to allow for appropriate spatial targeting of management opportunities  Segment and subbasin boundaries should reflect major changes in topography and soils to the extent practicable For many HSPF applications, segments are designed to provide a consistent relationship to individual weather stations. For Clarks Creek a single weather station is used, and the major decision is thus the appropriate subbasin size for building management scenarios. There is a tradeoff between model resolution, model run times, and level of effort in model setup. An appropriate scale for the development, calibration, and application of a computationally efficient sediment model is one that isolates the major urban storm drainages, but does not require more than 100 or so total subbasins to simulate the entire basin. For Clarks Creek this results in subbasins on the scale of approximately 100 acres. 4.1 SURFACE DRAINAGE SEGMENTATION The available data for completing the segmentation are a fine-scale digital elevation model (DEM) obtained from 6-foot resolution LiDAR, hydrographic coverage from the National Hydrography Dataset (NHD), detailed stormwater system mapping from both the City of Puyallup and Pierce County, and jurisdictional boundaries. Subbasins were delineated consistent with the DEM, NHD, and stormwater system information. Subbasins are generally arranged so that tributaries and major storm sewer inputs enter at the upstream end, and subbasin boundaries are set to correspond to critical water quality and flow monitoring points (Figure 4-1). The final subbasin segmentation is shown in Figure 4-2. Two areas of special interest are highlighted on Figure 4-2. The area in light red (subbasins 201 – 203) represents storm drainage along Pioneer Way that is being considered for diversion to the Puyallup River at 15th Street. The area in blue (subbasin 301) represents a subwatershed that is controlled by a flow splitter owned by WSDOT. The flow splitter directs most of the flow to the Puyallup River, but does allow some overflow into the Clarks Creek watershed (see Section 4.2.4). ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 4-2 Figure 4-1. Monitoring and Gage Locations in Clarks Creek #0 #0 #0 #0 #0 #0 GF GF GF GF GF GF &3 &3 &3 &3&3 &3 &3 DeCoursey Park Clarks Creek Park Maplewood Springs State Fish Hatchery WSU Extension Office H CC7 CC6 CC5 CC4 CC3 CC2 CC1 CLK-9 CLK-8 CLK-7 CLK-6 CLK-5 CLK-4 CLK-3 CLK-1 City-7 City-6 City-5 City-4 City-3 City-2 City-1 WURS-1 RURS-1 DURS-2 MDURS-2 MDURS-1 CCURS-5 CCURS-4 CCURS-3 CCURS-2 CCURS-1 CLK-4.1 MS118 MS074 MS048 12102050 12102100 12102020 12102075 (CLK-TR) Clarks Creek Watershed Monitoring Station and Gage Location Map Map produced by B. Tucker, 09-15-2010 NAD_1983_HARN_StatePlane_Washington_South_FIPS_4602_Feet 0 0.5 1 0.25 Kilometers 0 0.4 0.8 0.2 Miles Legend #0Points of Interest GFUSGS Gages ^_Pierce Co. Monitoring Stations Compiled Monitoring Stations &3City !.Ecology !.PTI !.WWF Major Streams Puyallup City Limits Clarks Creek Watershed Rody Creek ¯ River Rd. Clarks Creek Woodland Creek Diru Creek Meeker Puyallup River ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 4-3 Figure 4-2. Subbasin Delineation for Clarks Creek HSPF Model 301 123 139 151 157 158 129 135 138 132 150 147 103 149 201 203 202 127 131 102 160 152 115 113 159 134 128 170 136 156 105 111 108 163 140 110 146 114 164 148 124 161 169 168 167 143 166 154 117 144 153 162 122 155 137 133 145 141 142 101 165 104 112 109 119 126 116 125 118 107 106 130 110 130 301 123 139 151 157 158 135 138 150 103 149 201 203 202 131 113 134 110 161 129 169 132 147 168 127 102 160 152 115 167 159 143 166 128 154 170 136 156 105 111 117 108 163 140 144 146 114 164 153 162 122 148 155 137 124 145 141 101 104 119 126 116 125 130 110 130 0 0.5 1 0.25 Miles Outlet subject to flow splitter (main flows routed to Puyallup River) Potential (Future) 15th St. Diversion to Puyallup River (201, 202, and 203) ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 4-4 4.2 REACH HYDRAULICS HSPF models hydrology, but does not directly simulate hydraulics. That is, the model is based on the principal of conservation of mass, but not the conservation of momentum. Hydraulic details, such as the speed of propagation of flood waves, have little impact on the water balance at time steps of a day or longer; however, hydraulics have important impacts on the energy exerted by flow, which is crucial to the examination of sediment scour and deposition. Therefore, it is important to incorporate a strong hydraulic representation in HSPF models that are designed for simulation of sediment transport. In HSPF, the hydraulic behavior of stream reaches is specified externally through use of Functional Tables (FTables) that define stage-storage-discharge relationships. This is essentially a lookup table that enables the program to determine via interpolation, given an instantaneous value of storage in the reach, what is the corresponding depth, surface area, wetted perimeter, outflow, and flow velocity. Where available, this information can be developed directly from a hydraulic model, such as HEC-RAS or SWMM. Both models are available for portions of the Clarks Creek drainage network. Simpler methods are used for other areas where hydraulic models have not been developed. 4.2.1 HEC-RAS Modeling HEC-RAS (Brunner, 2010) is a one-dimensional hydraulic model of water flowing through open channels. Capable of modeling complex stream networks, hydraulic structures, dendritic systems or a single river reach, HEC-RAS is typically used for channel flow analysis and floodplain determination. HEC-RAS applications provide an excellent basis for creating the FTables at selected points within a stream network. The accuracy of the generated FTable is dependent upon the spacing and number of HEC-RAS cross sections throughout a stream network, as well as the accuracy of the measured flows used to correlate river stage to discharge. Starting with the design flow profiles provided with a HEC-RAS model flows from the 10-, 50-, 100-, 500-year return periods), the HSPF modeler can interpolate additional flow profiles to complete a model FTable. For Clarks Creek, a HEC-RAS model of the mainstem and a part of Meeker Creek was developed as part of the Flood Insurance Study (NHC, 2005). Additional cross sections were collected and the model expanded by Brown and Caldwell as part of this sediment study (Figure 4-3). The resulting model extends from mile zero (the confluence with the Puyallup River) to mile 4.502 (in subbasin 135 in Clarks Creek Park). It also covers the lower 0.9 miles of Meeker Creek. Tetra Tech added additional flow profiles to the HEC-RAS model. For each flow profile, HEC-RAS provides the following outputs that can be used for FTable generation:  Q Total – total flow in cross section (cfs)  Length Wt – weighted cross section reach length based on flow distribution (ft)  Max Chl Dpth – maximum main channel depth (ft)  SA Total – cumulative surface area for entire cross section from the bottom of the reach (acres)  Volume – cumulative volume of water in the direction of computation (acre-ft) Each point (or flow profile) representing the discharge-storage-surface area relationship by computed FTable is thus a weighted average of channel stage and discharge that is based on the weighted cross section reach length within the entire modeled reach. Also included for each flow profile in the FTable are the cumulative surface area and water volume between the reaches’ upstream and cross section. The HEC-RAS model provides FTables for HSPF reaches 101, 104, 106, 107, 109, 112, 114, 115, 122, 123, 133, 134, and 135. ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 4-5 Figure 4-3. HEC-RAS Model and Additional Stream Cross-Section Locations for Clarks Creek Figure courtesy of Brown and Caldwell. 4.2.2 SWMM Modeling The Storm Water Management Model (SWMM; Rossman, 2010) is a hydraulic model that can simulate both open channel and piped flow, including pressurized flow. Brown and Caldwell developed a SWMM application for the Pioneer Avenue drainages in downtown Puyallup (Figure 4-4). Stormwater in this area is primarily conveyed in closed pipes, so the existence of a SWMM model is particularly useful. Output from SWMM can be used in a manner similar to output from HEC-RAS to develop FTables. This was done using custom VBA scripts to retrieve output from the SWMM binary output file. This yields FTables for subbasins 111, 201, 202, and 203 in the HSPF model. ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 4-6 Figure 4-4. SWMM Model Incorporating Pioneer Avenue Drainage to Clarks Creek Figure courtesy of Brown and Caldwell 4.2.3 Other Cross Sections Brown and Caldwell also collected cross-section data for a number of locations outside the HEC-RAS model (shown by black dots in Figure 4-3). Flow at these cross sections was analyzed using a normal depth approximation in the by Brown and Caldwell. These results were aggregated in a manner similar to the output from the HEC-RAS models to produce FTables for reaches 127, 128, 142, 146, 147, 155, 157, 163, 164, and 166. In the remaining (mostly smaller, headwater) reaches in the model for which hydraulic models are not available, FTables were generated by the same method used in the BASINS system for HSPF model development (Moore, 2007). This approach is based on trapezoidal channel assumptions and simplified regression relationships for channel form and will have reduced accuracy relative to the FTables developed from site-specific hydraulic models. Of particular note, no hydraulic models were available for the piped stormwater conveyance systems at 7th Avenue. 4.2.4 WSDOT Flow Splitter Reach 301 is a special case due to the presence of a flow splitter at Highway 512. As build plans from WSDOT show a concrete weir was constructed at this location in 1993 to divert flows into a 30” diameter PCCP stormwater pipe that proceeds along Highway 512 and drains to the Puyallup River. Excess flows ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 4-7 that exceed the weir crest overflow into a 6’ x 4’ box culvert that proceeds under Highway 512 toward Clarks Creek. Flow starts topping the weir at about 26.2 cfs total outflow, but the pipe flow increases with increased head to a maximum of about 48 cfs. The weir was designed to also have a low flow orifice leading to the culvert, but that is reported to be plugged with sediment based on personal inspection by the Brown and Caldwell team. An FTable was therefore created for this reach that conforms to the as- built plans and has two exits, with only the weir overflow routed into the next segment of the Clarks Creek model. 4.3 GROUNDWATER INTERACTIONS As noted above, an important feature of the watershed is the presence of headwater springs on the Clarks Creek mainstem. A detailed north-south conceptual representation of the hydrogeology just west of the Clarks Creek mainstem (according to Savoca et al., 2010) is shown in Figure 4-5, while the plan view extent of the various aquifers is summarized in Figure 4-6. Under Savoca’s conceptualization, the springs at the headwaters of Clarks Creek (which also occur to a lesser extent on its major tributaries) are due to a combination of discharges from the A1, A3, and C aquifers, the first two of which tail out at the point where Clarks Creek and its tributaries enter the lower alluvial valley, and all of which have hydraulic heads higher than ground surface in the alluvial valley (Figure 4-6). The preliminary evaluation of flow directions in each aquifer provided by Savoca et al. (Figure 4-6) suggests that flow to the Clarks Creek springs may derive from a considerable distance to the south and southeast. This finding appears to be confirmed by recent groundwater modeling of the aquifers (Johnson et al., 2011). However, the exact contributing area to the springs (and the groundwater divide with the Clover Creek drainage) does not appear to be firmly established – although it is likely that that the Clarks Creek groundwatershed includes some of the internally drained pothole regions to the south and east of the surface drainage network. Because the surface area contributing flow to the Clarks Creek springs is not fully known, an empirical approach was developed to simulate the till groundwater balance on a unit area basis with the applicable area determined during calibration. The development of this representation is described in Section 6.2. ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 4-8 Figure 4-5. Detail of North-South Section West of Clarks Creek Headwaters (from Savoca et al., 2010, Plate 2) 4.4 STORMWATER PONDS Many developments in the Clarks Creek watershed were built with stormwater detention ponds to control peak flows. These were mostly built under older rules that were focused on flooding issues and not on water quality or protection of channel morphology and are thus designed to achieve only short-term retention of storm flows. Nonetheless, these ponds do provide some flow-control and water quality benefits. Unfortunately, the exact details on existing private stormwater infrastructure in the watershed are not well established. Pierce County has an inventory and GIS coverage of private stormwater ponds within its jurisdictional area, but this does not include complete information on pond size or drainage area. There are also anecdotally many private stormwater ponds within the City of Puyallup, but no comprehensive database on these ponds has been assembled. Therefore, an approximation approach is needed to address the role of private stormwater ponds in the watershed. It is assumed that most of the stormwater ponds in the watershed receive primarily runoff from impervious surfaces that is temporarily detained but not infiltrated. This behavior is approximated as surface detention storage in the impervious land simulation. In HSPF, precipitation onto impervious areas is first subject to retention (on overhanging trees, flat roofs, etc.) that is subject to evaporation. Once this store is filled, supply is routed to surface storage. The surface storage (which is not subject to evaporation) runs off in accordance with a simple Chezy-Manning representation that considers surface ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 4-9 roughness (Manning’s n) and path length. The surface storage routine can be used to represent temporary detention by decreasing the value of the routing variable, SRC, which is calculated internally as LSUR NSUR SLSUR SRC   1020 , where SLSUR is the slope, NSUR is the Manning’s roughness coefficient, and LSUR is the slope length (ft). Increasing the value of the product NSUR·LSUR will effectively decrease the routing variable, approximating stormwater detention. The program does not allow NSUR to exceed 1; however, LSUR has no prescribed upper limit. Therefore, artificially high values of LSUR are used to approximate detention. The appropriate value of LSUR in this representation is a calibration parameter because the fraction of stormwater that is subject to such detention is not known. The product NSUR·LSUR was set to 4,950 for high density residential impervious surfaces and 2,475 for medium density residential impervious surfaces in the final model. Other impervious surfaces were assumed, on average, to not be subject to significant amounts of stormwater detention. ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 4-10 Figure 4-6. Interpreted Groundwater Flow in the A1, A3, and C Aquifers in the Vicinity of Clarks Creek (details from Savoca et al., 2010, figures 17-19) Note: Clarks Creek shown in upper left of each figure. ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 4-11 The original USGS model (Mastin, 1996) covered Clear, Swan, and Canyon Creeks, but only Rody (West Fork Clarks Creek) and Diru Creek in the Clarks Creek watershed. This model was later expanded to include all of Clarks Creek as part of the 2003 basin plan. When the model was expanded, the original approach taken by Mastin to represent groundwater interactions was retained. Specifically, each creek is represented as having a losing reach that contributes to a common groundwater reservoir (represented in the model as a stream reach segment). The groundwater reservoir in turn yields flow back to segments of various reaches, including Rody, Diru, and Clarks Creek, but not Woodland Creek. In the case of the Clarks Creek mainstem, losses to groundwater are represented as occurring between the State Hatchery and Meeker Ditch, while discharges from groundwater to the stream are represented as occurring at the confluence with Diru Creek. Similarly, Rody and Diru Creek have losses to groundwater in the upper reaches and gains from groundwater in the reach immediately above the confluence with Clarks Creek. The representation of groundwater interactions in the existing model is now known to be inconsistent with the hydrogeology of the area. Specifically, significant discharges from groundwater to stream occur along the slope face where the outwash merges into the alluvial valley. Estimates of stream gain or loss presented by Savoca et al. (2010) suggest there may be minor losses from the stream in the general vicinity of Meeker Ditch, and perhaps small inflows between Tacoma Road and the mouth (both interactions with the AL aquifer), as is also shown by flow estimates during the 2002-2003 field sampling effort analyzed by Tetra Tech as part of the dissolved oxygen TMDL effort. The interactions with the AL aquifer correspond to the general longitudinal profile of Clarks Creek (Figure 4-7), as the groundwater elevation along lower Clarks Creek is about 25 m (Savoca et al., 2010). However, inflow from groundwater below Tacoma Road is likely derived from upstream portions of the Puyallup River, rather than from a local groundwater reservoir derived from losing reaches of Clarks Creek and its tributaries. Figure 4-7. Longitudinal Profile of Clarks Creek The additional insights on hydrogeology of the system suggested it was appropriate to refine the approach in the original USGS model. Simulation of a groundwater reservoir is still useful to represent the springs at the edge of the glacial outwash, such as Maplewood Springs. However, this reservoir is filled not by losses from the streams but rather by infiltration to the aquifers in an upstream area that includes pothole regions not connected by surface drainage to Clarks Creek. The groundwater reservoir, representing the A1 and A3 aquifers, should thus be simulated as receiving water from pervious upland segments with an areal extent greater than the local drainage area. The revised method is described in Section 6.2. 0 5 10 15 20 25 30 35 40 45 50 0 1 2 3 4 5 6 7 Elevation Distance Upstream (km) TacomaRd MaplewoodSprings Meeker ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 4-12 (This page left intentionally blank.) ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 5-1 5 Model Calibration and Validation Approach Calibration consists of the process of adjusting model parameters to provide a match to observed conditions. Calibration is necessary because of the semi-empirical nature of water quality models. Although these models are formulated from mass balance principles, most of the kinetic descriptions in the models are empirically derived. These empirical derivations contain a number of coefficients that are usually determined by calibration to data collected in the waterbody of interest. Calibration tunes the models to represent conditions appropriate to the waterbody and watershed under study. However, calibration alone is not sufficient to assess the predictive capability of the model, or to determine whether the model developed via calibration contains a valid representation of cause and effect relationships, especially those associated with the principal study questions. To help determine the adequacy of the calibration and to evaluate the uncertainty associated with the calibration, the model is subjected to a corroboration or validation step. In the corroboration step, the model is typically applied to a set of data independent from that used in calibration. This helps to ensure that the calibration is robust, and that the quality of the calibration is not an artifact of over-fitting to a specific set of observations. Corroboration or validation tests can also provide a direct estimate of the magnitude of uncertainty that may be expected when the model is applied to conditions outside of the calibration series. 5.1 ACCEPTANCE CRITERIA FOR MODEL CALIBRATION The quality of model calibration and validation is evaluated relative to acceptance criteria and performance targets specified in the QAPP (Tetra Tech, 2011). The intended uses of the model focus on the effectiveness and cost-effectiveness of different implementation strategies relative to management of sediment in Clarks Creek. As such, the ability of the models to represent the relative contributions of different source areas and the relative performance of different management measures is of greatest importance, while obtaining a precise estimate of loading time series is of less direct interest. Ideally, the models should attain tight calibration to observed data; however, a less precise calibration can still provide useful information. In light of these uses of the models, it is most informative to specify performance target ranges of precision that characterize the model results as “very good,” “good,” “fair,” or “poor.” These characterizations inform appropriate uses of the model: Where a model achieves an excellent fit it can assume a strong role in evaluating management options. Conversely, where a model achieves only a fair or poor fit it should assume a much less prominent role in the overall weight-of-evidence evaluation of management options. The general acceptance criterion for models to be applied in this project is to achieve a quality of fit of “good” or better. In the event that this level of quality is not achieved on some or all measures the model may still be useful; however, a detailed description of its potential range of applicability should be provided. 5.2 PERFORMANCE TARGETS FOR HSPF For HSPF, a variety of performance targets have been specified, including Donigian et al. (1984), Lumb et al. (1994), and Donigian (2000). Based on these references and previous experience with the model, the HSPF performance targets for simulation of the water balance components are summarized in Table 5-1. ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 5-2 Table 5-1. Performance Targets for HSPF Hydrologic Simulation (Magnitude of Annual and Seasonal Relative Mean Error (RE); Daily and R2) Model Component Very Good Good Fair Poor 1. Error in total volume ≤ 5% 5 - 10% 10 - 15% > 15% 2. Error in 50% lowest flow volumes ≤ 10% 10 - 15% 15 - 25% > 25% 3. Error in 10% highest flow volumes ≤ 10% 10 - 15% 15 - 25% > 25% 4. Error in storm volume ≤ 10% 10 - 15% 15 - 25% > 25% 5. Winter volume error ≤ 15% 15 - 30% 30 - 50% > 50% 6. Spring volume error ≤ 15% 15 - 30% 30 - 50% > 50% 7. Summer volume error ≤ 15% 15 - 30% 30 - 50% > 50% 8. Fall volume error ≤ 15% 15 - 30% 30 - 50% > 50% 9. R2 daily values > 0.80 > 0.70 > 0.60 ≤ 0.60 10. R2 values > 0.85 > 0.75 > 0.65 ≤ 0.65 It is important to clarify that the tolerance ranges are intended to be applied to mean values, and that individual events or observations may show larger differences and still be acceptable (Donigian, 2000). In addition, the Nash-Sutcliffe coefficient of model fit efficiency is reported for all calibration and validation runs – although no specific acceptance criteria were proposed in the QAPP. This is calculated as           2 2 1 O O P O E i i i , where Oi indicates an observed value, Pi a predicted value, and the overbar indicates an average. An E value of 1 indicates a perfect fit between measured and predicted values for all events. The resulting index can range from negative infinity to 1, with higher values indicating better fit. A value of zero indicates that the calibrated model is no better than using the average value of all the measured data to predict individual measurements. General performance targets for water quality simulation with HSPF are also provided by Donigian (2000) and are shown in Table 5-2. These are calculated from observed and simulated daily values, and should only be applied in cases where there are a minimum of 20 observations ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 5-3 Table 5-2. Performance Targets for HSPF Water Quality Simulation (Magnitude of Relative Error (RE) on Daily Values) Model Component Very Good Good Fair Poor 1. Suspended Sediment ≤ 20% 20 - 30% 30 - 45% > 45% 2. Nutrients ≤ 15% 15 - 25% 25 - 35% > 35% ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 5-4 (This page left intentionally blank.) ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 6-1 6 Hydrologic Calibration and Validation The hydrology model is calibrated to observed flow gaging data. The primary source of flow data for calibration is the USGS gage on Clarks Creek at Tacoma Road (Station 12102075; see Figure 4-1). Gage records at this station are available for 3/1/1995 through 11/25/2008. Figure 6-1 compares recorded flows on Clarks Creek to those on nearby Clover Creek. Clarks Creek immediately stands out as having a near constant baseflow, and also being somewhat less responsive to winter storm events Figure 6-1. Comparison of Flow Gaging on Clarks Creek and Clover Creek, 1995-2008 To provide for model validation, flow calibration was undertaken on the gage data for 2000 – 2008, while the data for 1995 – 1999 were used for a validation test. Scattered flow measurements exist for other locations, but are not sufficient for formal calibration. The comparison of the model to these records is discussed in Section 6.5. 6.1 PARAMETER SELECTION The existing HSPF model of the area (Mastin, 1996) was used as a starting point for parameter values used in calibration; however, a need for significant modification was expected due to the more refined analysis of HRUs in the current model. From this starting point, parameters were varied in accordance with recommended ranges and other guidance for the HSPF model (USEPA, 2000). Model parameters are assigned in a spreadsheet to individual HRUs based on the intersection of soil group, land use, and slope. Table 6-1 shows key hydrologic parameters that are assigned by soil group. One of the most important is INFILT, which is HSPF’s index to mean soil infiltration rate (in/hr; the actual infiltration rate depends on soil moisture storage). Mastin used values for INFILT that were not divided by HSG. The revised model fits well with values that are within or near the recommended ranges for each HSG. 0 50 100 150 200 250 300 350 400 450 Mar-95 Jun-95 Sep-95 Dec-95 Mar-96 Jun-96 Sep-96 Dec-96 Mar-97 Jun-97 Sep-97 Dec-97 Mar-98 Jun-98 Sep-98 Dec-98 Mar-99 Jun-99 Sep-99 Dec-99 Mar-00 Jun-00 Sep-00 Dec-00 Mar-01 Jun-01 Sep-01 Dec-01 Mar-02 Jun-02 Sep-02 Dec-02 Mar-03 Jun-03 Sep-03 Dec-03 Mar-04 Jun-04 Sep-04 Dec-04 Mar-05 Jun-05 Sep-05 Dec-05 Mar-06 Jun-06 Sep-06 Dec-06 Mar-07 Jun-07 Sep-07 Dec-07 Mar-08 Jun-08 Sep-08 Clover Creek 12090500 Clarks Creek 12102075 ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 6-2 Table 6-1. Hydrologic Parameter Assignment by Soil Group Soil INFILT (in/hr) LZSN (in) This Model Mastin (1996) Recommended (USEPA, 2000) This Model Mastin (1996) Recommended (USEPA, 2000) Till AB 0.4 0.08 (forest) 0.3 (other) 0.1 – 1.0 13 6 3.0 – 8.0 (typical) 2.0 – 15.0 (possible) Till C 0.12 (0.09 ag.) 0.05 – 0.1 12 6 Till D 0.05 0.01 – 0.05 12 6 Alluvial A 0.6 2.0 (forest) 0.8 (other) 0.4 – 1.0 12 5 Alluvial CD 0.10 (0.15 forest) 0.01 – 0.10 11 5 AGWRC DEEPFR Till AB 0.980 0.993 (forest) 0.800 0.92 – 0.99 (typical) 0.85 – 0.999 (possible) 0.20 0.25 0 – 0.20 (typical) 0 – 0.50 (possible) Till C 0.20 Till D 0.15 Alluvial A 0.996 0.996 0 0 Alluvial CD A parameter of particular interest is LZSN, the lower zone nominal soil storage (in). LZSN is an index of the amount of water that soil can hold within the root zone and subject to evapotranspiration by plants and is independent of infiltration rates. We found that model calibration statistics improved markedly with higher values of LZSN, and this was increased greatly from the values proposed by Mastin (1996) to a value of 11 - 13 inches, near the top of the typical range cited in USEPA (2000). Attempts to find alternate model fits with lower values of LZSN by modifying other parameters such as INFILT and INTFW uniformly yielded poorer fits to the observed gage records. The choice of a high value of LZSN means that, even where infiltration rates are low, the ultimate infiltration capacity of the soil is large, resulting in greater fractions of the total flow proceeding by interflow and groundwater pathways. This results in much of the direct stormflow in the Clarks Creek basin being simulated as derived from impervious surfaces. The other parameters in Table 6-1 are the active groundwater recession coefficient (AGWRC) and the fraction of active groundwater storage that is lost to deep pathways (DEEPFR). A relatively large value is appropriate for DEEPFR on the till due to the recharge that feeds springs throughout the area. Parameters that control interflow are varied by soil and slope (Table 6-2). Mastin fit very high values of the interflow inflow parameter, INTFW, for the till and these were retained after demonstrating that reduced values provided a poorer fit. Interflow was also activated for the alluvial soils. On the other hand, Mastin’s values for the interflow recession coefficient (IRC) appear far too low and were revised to more typical values (USEPA, 2000). parameter values were assigned to the lower zone ET factor (LZETP) and forest interception (CEPSC) consistent with past experience with HSPF models in the Northwest. These parameters are primarily determined by plant growth stage and are summarized in Table 6-3. Retention on impervious surfaces is also varied by month and shown in Table 6-3. ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 6-3 Table 6-2. Hydrologic Parameter Assignments by Slope and Soil Slope INTFW IRC This Model Mastin (1996) Recommended (USEPA, 2000) This Model Mastin (1996) Recommended (USEPA, 2000) 0 – 6% 6 (till) 2 (alluvial) 6 (till) 0 (alluvial) 1 – 3 (typical) 1 – 10 (possible) 0.7 (A-B) 0.8 (C-D) 0.15 (till) 0.5 – 0.7 (typical) 0.3 – 0.85 (possible) 6 – 12% 9 (till) 2 (alluvial) 9 (till) 0 (alluvial) 0.65 (A-B) 0.76 (C-D) 0.12 (till) > 12% 11 (till) 2 (alluvial) 11 (till) 0 (alluvial) 0.6 (A-B) 0.7 (C-D) 0.10 (till) Table 6-3. Hydrologic Parameter Assignments by Month LU Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec LZETP Forest 0.4 0.5 0.55 0.65 0.65 0.65 0.6 0.55 0.35 0.35 0.3 0.3 Agriculture 0.16 0.19 0.2 0.25 0.35 0.65 0.8 0.8 0.56 0.18 0.14 0.14 Pasture 0.45 0.45 0.45 0.45 0.45 0.45 0.45 0.45 0.45 0.45 0.45 0.45 Residential Pervious 0.45 0.45 0.45 0.45 0.45 0.5 0.45 0.4 0.35 0.35 0.35 0.4 Road Pervious 0.45 0.45 0.45 0.45 0.45 0.45 0.45 0.45 0.45 0.45 0.45 0.45 Park 0.4 0.5 0.6 0.6 0.6 0.6 0.6 0.55 0.4 0.4 0.4 0.4 CEPSC Forest > 70% 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.2 0.15 0.15 0.15 Forest < 70% 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15 Agriculture 0.04 0.04 0.04 0.04 0.05 0.06 0.12 0.143 0.15 0.105 0.07 0.05 Pasture 0.10 0.10 0.10 0.10 0.10 0.10 0.10 0.10 0.10 0.10 0.10 0.10 Residential Pervious 0.10 0.10 0.10 0.10 0.10 0.10 0.10 0.10 0.10 0.10 0.10 0.10 Road Pervious 0.10 0.10 0.10 0.10 0.10 0.10 0.10 0.10 0.10 0.10 0.10 0.10 Park 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15 RETN (in) MD – HD Residential Impervious 0.1 0.15 0.15 0.1 0.1 0.1 0.1 0.1 0.05 0.05 0.05 0.05 LD Residential Impervious 0.25 0.25 0.25 0.1 0.1 0.1 0.1 0.05 0.05 0.05 0.05 0.1 Road Impervious 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 Park Impervious 0.25 0.25 0.25 0.1 0.1 0.1 0.1 0.05 0.05 0.05 0.05 0.1 ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 6-4 6.2 GROUNDWATER MODEL SETUP FOR SPRING DISCHARGE One of the biggest challenges for simulating the hydrology of Clarks Creek is representing the incremental groundwater inflow from the Vashon Till. As described in Section 4.3, this flow originates from an area that is significantly larger than the surface drainage network of Clarks Creek – but, at this time, the extent of the contributing area is not exactly known. Flow recorded at the USGS gage on Clarks Creek at Tacoma Road shows a persistent baseflow component ranging between 40 and 60 cfs that is associated with these springs. This baseflow is always present, but does respond to climate, declining after dry periods and increasing after wet periods. Given that no groundwater model is currently available and the size of the contributing area for baseflow is unknown an iterative approach was taken to simulating the spring flow entering the system. In essence, this approach involved simulating a representative pervious land segment (on a per-acre basis) and optimizing a fit to estimated spring flow based on the pervious land segment contributions to active groundwater. The target for the optimization is a smoothed lower bound estimate of spring flow obtained by applying a sliding window baseflow separation routine to observed flows at Tacoma Road, then identifying the objective function as the smoothed 3-month average of the 25th percentile of the baseflow sums. Aquifer outflows to the surface water model were calculated separately in a spreadsheet. The aquifer mass balance is represented at a scale by a storage (St) and an outflow (Ot) term (both in/mo). In addition, there is assumed to be leakage to lower aquifers that do not reemerge in Clarks Creek. The aquifer storage is: t t t t t O S k I S S       2 1 1 , where k is a leakage coefficient. The outflow term (in/mo) is then given as a central difference on previous and partially updated storage terms:   t b t t b t t m O S MAX a S a O        2 ) 0 , ( 1 1 1 , where a and b are parameters and m is a adjustment factor. Finally, the outflow in in/mo can be converted to an outflow in cfs by multiplying by an area factor, r, which has units of cfs/(in-mo) but is essentially a calibration factor to relate the unit area outflow term to the unknown contributing area: t O r Q   . This model has four constants b, k, and plus a set of factors For fitting purposes, inflow to the aquifer was assumed to occur from a forested land segment on low slopes with A soils, characterized by the parameters assumed for the Mastin (1996) model. The A soils assumption is appropriate given the assumption that the majority of the recharge occurs over more pervious sand deposits. Fit was based on minimizing squared differences on the smoothed objective function over the period of gaging at Tacoma Road (1995-2008), using a model run that started in 1960 with an assumed storage of 34 in (a value selected to maintain an approximately stable groundwater storage over the 50-year simulation period). Optimized parameter values are shown in Table 6-4. Note that the value obtained for r suggests that there is an additional drainage area of approximately 1 ½ square miles contributing to the groundwater flow that discharges to Clarks Creek through springs at the base of the Vashon Till. ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 6-5 Table 6-4. Groundwater Model Parameter Estimates for Clarks Creek Parameter Estimate a 2.09 · 10-11 in b 5.611 k 2.26 · 10-4 (in-mo)-1 r 6,980 cfs/(in-mo) These parameters provide a reasonable match to the lower bound estimates of spring-fed baseflow for 1995-2008 over long term simulations started in 1960 (Figure 6-2). The match is not, however, exact, and appears to introduce discrepancies in some years. Figure 6-2. Calibrated Fit to Inferred Spring Contribution to Clarks Creek Flow The outflow from the groundwater springs upstream of the Tacoma Road gage was assigned 77% to Reach 133, 17 % to reach 134, and 6% to reach 135 based on limited flow monitoring at various points in the system conducted in 2002-2003. In addition, small amounts of spring outflow were assigned to Rody Creek (1.85% of the flow to the mainstem) and Diru Creek (1.06% of the flow to the mainstem). 6.3 HYDROLOGY MODEL CALIBRATION The hydrology model calibration (2000 – 2008) is summarized below in Figure 6-3 through Figure 6-10, Table 6-5, and Table 6-6. At certain points during this period the uncertainties introduced by the spring discharge model are evident the second half of 2003, during which baseflow steadily increased despite the absence of significant rain). Nonetheless, the overall model fit is rated as good. As shown in Table 6-6, all of the annual and seasonal relative mean error statistics are in the “very good” range (refer to the performance targets in Table 5-1). The uncertainties introduced by the spring simulation, which has some difficulties in representing the short-term variations in baseflow discharge, are, however, evident in the relatively low daily E value of 0.54. The coefficient of determination (R2) for daily discharges is 0.70 (Figure 6-5), which is in the good range. The coefficient of determination for discharges is, however, poor (Figure 6-6). This is largely due to two periods in which the model under-predicts observed flow (Nov.-Dec. 2002 and Nov.-Dec. 2006). Despite this, the E (0.95) is very high. Therefore, the model calibration is deemed acceptable. 0 10 20 30 40 50 60 70 80 1995 1995 1996 1996 1996 1997 1997 1998 1998 1998 1999 1999 2000 2000 2001 2001 2001 2002 2002 2003 2003 2003 2004 2004 2005 2005 2006 2006 2006 2007 2007 2008 2008 Predicted Observed ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 6-6 Figure 6-3. Mean Daily Flow: Model vs. USGS 12102075 Clarks Creek at Tacoma Road near Puyallup, WA, Calibration Period Figure 6-4. Mean Flow: Model vs. USGS 12102075 Clarks Creek at Tacoma Road near Puyallup, WA, Calibration Period 0 2 4 6 8 10 12 14 0 50 100 150 200 250 300 Jan-00 Jan-01 Jan-02 Jan-03 Jan-04 Jan-05 Jan-06 Jan-07 Jan-08 Daily Rainfall (in) Flow (cfs) Date Avg Rainfall (in) Avg Observed Flow (1/1/2000 to 11/30/2008 ) Avg Modeled Flow (Same Period) 0 2 4 6 8 10 12 14 0 50 100 150 J-00 J-01 J-02 J-03 J-04 J-05 J-06 J-07 J-08 Rainfall (in) Flow (cfs) Month Avg Rainfall (in) Avg Observed Flow (1/1/2000 to 11/30/2008 ) Avg Modeled Flow (Same Period) ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 6-7 Figure 6-5. Daily Flow Regression: Model vs. USGS 12102075 Clarks Creek at Tacoma Road near Puyallup, WA, Calibration Period Figure 6-6. Flow Regression and Temporal Variation: Model vs. USGS 12102075 Clarks Creek at Tacoma Road near Puyallup, WA, Calibration Period y = 0.664x + 19.625 R² = 0.7007 0 50 100 150 200 250 0 50 100 150 200 250 300 350 Simulated Flow (cfs) Observed Flow (cfs) y = 0.5799x + 22.22 R² = 0.5125 0 50 100 150 0 50 100 150 Average Modeled Flow (cfs) Average Observed Flow (cfs) Avg Flow (1/1/2000 to 11/30/2008 ) Line of Equal Value Best-Fit Line 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% J-00 J-01 J-02 J-03 J-04 J-05 J-06 J-07 J-08 Water Balance (Obs + Mod) Month Avg Observed Flow (1/1/2000 to 11/30/2008 ) Avg Modeled Flow (1/1/2000 to 11/30/2008 ) Line of Equal Value ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 6-8 Figure 6-7. Seasonal Regression and Temporal Aggregate: Model vs. USGS 12102075 Clarks Creek at Tacoma Road near Puyallup, WA, Calibration Period Figure 6-8. Seasonal Medians and Ranges: Model vs. USGS 12102075 Clarks Creek at Tacoma Road near Puyallup, WA, Calibration Period Table 6-5 Seasonal Summary: Model vs. USGS 12102075 Clarks Creek at Tacoma Road near Puyallup, WA, Calibration Period y = 0.7395x + 13.661 R² = 0.7188 0 50 100 0 50 100 Average Modeled Flow (cfs) Average Observed Flow (cfs) Avg Flow (1/1/2000 to 11/30/2008) Line of Equal Value Best-Fit Line Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 0 1 2 3 4 5 6 0 50 100 1 2 3 4 5 6 7 8 9 10 11 12 Rainfall (in) Flow (cfs) Month Avg Rainfall (in) Avg Observed Flow (1/1/2000 to 11/30/2008) Avg Modeled Flow (Same Period) Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 0 1 2 3 4 5 6 0 10 20 30 40 50 60 70 80 1 2 3 4 5 6 7 8 9 10 11 12 Rainfall (in) Flow (cfs) Month Observed (25th, 75th) Average Rainfall (in) Median Observed Flow (1/1/2000 to 11/30/2008) Modeled (Median, 25th, 75th) ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 6-9 Figure 6-9. Flow Exceedence: Model vs. USGS 12102075 Clarks Creek at Tacoma Road near Puyallup, WA, Calibration Period MEAN MEDIAN 25TH 75TH MEAN MEDIAN 25TH 75TH Jan 63.17 60.00 54.00 67.00 61.33 58.73 50.54 66.92 Feb 54.58 52.00 48.00 59.50 57.88 57.88 48.94 63.65 Mar 54.19 52.00 44.00 62.00 58.37 56.49 49.86 65.51 Apr 52.56 51.00 45.00 60.00 55.60 55.41 48.26 61.58 May 49.89 47.00 43.00 58.00 52.69 52.04 47.32 56.92 Jun 48.09 46.00 41.00 55.00 48.54 47.48 43.91 52.90 Jul 47.21 49.00 44.00 52.00 47.91 47.47 44.23 52.34 Aug 48.91 50.00 45.00 53.00 46.39 44.88 42.13 50.50 Sep 47.96 48.00 44.00 52.00 45.69 44.43 41.61 49.69 Oct 52.59 51.00 49.00 55.00 51.31 46.95 43.73 53.62 Nov 62.54 56.00 50.00 65.00 56.34 52.46 45.54 60.11 Dec 64.54 58.00 52.00 74.00 59.80 56.16 51.87 64.65 MONTH OBSERVED FLOW (CFS) MODELED FLOW (CFS) 33 330 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% Daily Average Flow (cfs) Percent of Time that Flow is Equaled or Exceeded Observed Flow Duration (1/1/2000 to 11/30/2008 ) Modeled Flow Duration (1/1/2000 to 11/30/2008 ) ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 6-10 Figure 6-10 . Flow Accumulation: Model vs. USGS 12102075 Clarks Creek at Tacoma Road near Puyallup, WA, Calibration Period 0% 20% 40% 60% 80% 100% 120% Jan-00 Jan-01 Jan-02 Jan-03 Jan-04 Jan-05 Jan-06 Jan-07 Jan-08 Normalized Flow Volume (Observed as 100%) Observed Flow Volume (1/1/2000 to 11/30/2008 ) Modeled Flow Volume (1/1/2000 to 11/30/2008 ) ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 6-11 Table 6-6. Summary Statistics: Model vs. USGS 12102075 Clarks Creek at Tacoma Road near Puyallup, WA, Calibration Period 6.4 HYDROLOGY MODEL VALIDATION The hydrology validation was conducted for 1995-1999 and confirms the performance of the calibrated model (Figure 6-11 through Figure 6-18, Table 6-6, and Table 6-7). The relative mean error statistics (Table 6-7) are all “very good”, with the exception of the storm volume error, which is only “good”. Reassuringly, the validation period statistics show an increase in the daily Nash-Sutcliffe E to 0.699 and the coefficients of determination (R2) are 0.744 for daily flows and 0.817 for flows, both in the “good” range. HSPF Simulated Flow Observed Flow Gage REACH OUTFLOW FROM DSN 103 8.92-Year Analysis Period: 1/1/2000 - 11/30/2008 Hydrologic Unit Code: 17110014 Flow volumes are (inches/year) for upstream drainage area Latitude: 47.19760016 This version has fix to hydrograph separation Longitude: -122.337343 Drainage Area (sq-mi): 13 Total Simulated In-stream Flow: 55.72 Total Observed In-stream Flow: 56.07 Total of simulated highest 10% flows: 8.30 Total of Observed highest 10% flows: 8.64 Total of Simulated lowest 50% flows: 23.64 Total of Observed Lowest 50% flows: 23.61 Simulated Summer Flow Volume (months 7-9): 12.40 Observed Summer Flow Volume 12.76 Simulated Fall Flow Volume (months 10-12): 14.14 Observed Fall Flow Volume (10-12): 15.16 Simulated Winter Flow Volume (months 1-3): 15.45 Observed Winter Flow Volume 14.97 Simulated Spring Flow Volume (months 4-6): 13.74 Observed Spring Flow Volume 13.18 Total Simulated Storm Volume: 2.60 Total Observed Storm Volume: 2.38 Simulated Summer Storm Volume 0.21 Observed Summer Storm Volume 0.23 Errors (Simulated-Observed) Error Statistics Recommended Criteria Run (n-1) Prev Cal Error in total volume: -0.62 10 -0.75 -0.41 Error in 50% lowest flows: 0.14 10 0.11 0.41 Error in 10% highest flows: -3.94 15 -4.39 -3.93 Seasonal volume error - Summer: -2.82 30 -2.78 -2.58 Seasonal volume error - Fall: -6.72 30 -6.75 -6.67 Seasonal volume error - Winter: 3.20 30 2.79 3.43 Seasonal volume error - Spring: 4.19 30 4.10 4.54 Error in storm volumes: 9.10 20 8.47 8.80 Error in summer storm volumes: -8.83 50 -8.79 -8.83 Nash-Sutcliffe Coefficient of Efficiency, E: 0.539 Model accuracy increases 0.540 0.538 NSE 0.950 as E approaches 1.0 0.950 0.950 USGS 12102075 CLARKS CREEK AT TACOMA ROAD NEAR PUYALLUP, WA ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 6-12 Figure 6-11. Mean Daily Flow: Model vs. USGS 12102075 Clarks Creek at Tacoma Road near Puyallup, WA, Validation Period Figure 6-12. Mean Flow: Model vs. USGS 12102075 Clarks Creek at Tacoma Road near Puyallup, WA, Validation Period 0 2 4 6 8 10 12 14 0 50 100 150 200 250 300 Mar-95 Mar-96 Mar-97 Mar-98 Mar-99 Daily Rainfall (in) Flow (cfs) Date Avg Rainfall (in) Avg Observed Flow (3/1/1995 to 12/31/1999 ) Avg Modeled Flow (Same Period) 0 2 4 6 8 10 12 14 0 50 100 M-95 M-96 M-97 M-98 M-99 Rainfall (in) Flow (cfs) Month Avg Rainfall (in) Avg Observed Flow (3/1/1995 to 12/31/1999 ) Avg Modeled Flow (Same Period) ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 6-13 Figure 6-13. Daily Flow Regression: Model vs. USGS 12102075 Clarks Creek at Tacoma Road near Puyallup, WA, Validation Period Figure 6-14. Flow Regression and Temporal Variation: Model vs. USGS 12102075 Clarks Creek at Tacoma Road near Puyallup, WA, Validation Period y = 0.924x + 4.2725 R² = 0.7442 0 50 100 150 200 250 300 0 50 100 150 200 250 300 350 Simulated Flow (cfs) Observed Flow (cfs) y = 0.893x + 6.2661 R² = 0.8174 0 50 100 0 50 100 Average Modeled Flow (cfs) Average Observed Flow (cfs) Avg Flow (3/1/1995 to 12/31/1999 ) Line of Equal Value Best-Fit Line 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% M-95 M-96 M-97 M-98 M-99 Water Balance (Obs + Mod) Month Avg Observed Flow (3/1/1995 to 12/31/1999 ) Avg Modeled Flow (3/1/1995 to 12/31/1999 ) Line of Equal Value ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 6-14 Figure 6-15. Seasonal Regression and Temporal Aggregate: Model vs. USGS 12102075 Clarks Creek at Tacoma Road near Puyallup, WA, Validation Period Figure 6-16. Seasonal Medians and Ranges: Model vs. USGS 12102075 Clarks Creek at Tacoma Road near Puyallup, WA, Validation Period Table 6-7. Seasonal Summary: Model vs. USGS 12102075 Clarks Creek at Tacoma Road near Puyallup, WA, Validation Period y = 1.1784x - 11.992 R² = 0.8669 0 20 40 60 80 0 20 40 60 80 Average Modeled Flow (cfs) Average Observed Flow (cfs) Avg Flow (3/1/1995 to 12/31/1999) Line of Equal Value Best-Fit Line Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb 0 1 2 3 4 5 6 7 8 9 0 20 40 60 80 3 4 5 6 7 8 9 10 11 12 1 2 Rainfall (in) Flow (cfs) Month Avg Rainfall (in) Avg Observed Flow (3/1/1995 to 12/31/1999) Avg Modeled Flow (Same Period) MEAN MEDIAN 25TH 75TH MEAN MEDIAN 25TH 75TH Mar 66.01 65.00 60.00 77.50 71.42 70.92 61.21 80.40 Apr 67.78 67.50 61.00 78.00 66.40 67.33 59.35 71.77 May 62.79 65.00 60.00 71.00 63.61 65.01 59.10 70.11 Jun 57.25 64.00 44.25 66.75 57.31 59.11 52.39 61.82 Jul 55.89 62.00 43.50 65.00 56.27 58.47 52.40 60.32 Aug 57.35 62.00 51.00 64.00 53.16 54.47 48.14 59.06 Sep 57.72 61.00 56.00 63.00 52.84 53.80 49.37 57.09 Oct 60.45 62.00 59.00 64.00 57.61 56.30 52.54 63.29 Nov 70.48 69.00 62.00 73.00 66.01 63.79 54.20 70.89 Dec 72.68 68.00 63.00 77.50 71.43 66.82 63.28 72.89 Jan 71.77 69.00 58.75 81.00 75.91 71.26 65.37 83.17 Feb 74.07 67.00 63.00 76.00 76.52 72.60 65.66 78.77 MONTH OBSERVED FLOW (CFS) MODELED FLOW (CFS) ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 6-15 Figure 6-17. Flow Exceedence: Model vs. USGS 12102075 Clarks Creek at Tacoma Road near Puyallup, WA, Validation Period Figure 6-18. Flow Accumulation: Model vs. USGS 12102075 Clarks Creek at Tacoma Road near Puyallup, WA, Validation Period 33 330 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% Daily Average Flow (cfs) Percent of Time that Flow is Equaled or Exceeded Observed Flow Duration (3/1/1995 to 12/31/1999 ) Modeled Flow Duration (3/1/1995 to 12/31/1999 ) 0% 20% 40% 60% 80% 100% 120% Mar-95 Mar-96 Mar-97 Mar-98 Mar-99 Normalized Flow Volume (Observed as 100%) Observed Flow Volume (3/1/1995 to 12/31/1999 ) Modeled Flow Volume (3/1/1995 to 12/31/1999 ) ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 6-16 Table 6-8. Summary Statistics: Model vs. USGS 12102075 Clarks Creek at Tacoma Road near Puyallup, WA, Validation Period 6.5 SIMULATION OF HOURLY FLOWS The USGS NWIS system provides access to 15-minute raw flow estimates from the Tacoma Road gage for the period 3/28/1995 – 9/30/2008 (with gaps). These can be used to evaluate model performance at its native hourly time step. Typical results for fall 2007 are shown in Figure 6-19. In general, the model simulation appears accurate, with good representation of storm hydrograph timing and shape for most events. There is one period on November 4, 2007 when gaged flow increased above 100 cfs with no recorded rainfall. Subdaily gage data are missing for December 16 to December 17, 2007. Figure 6-19. Hourly Flow Prediction for Clarks Creek at Tacoma Rd., Fall 2007 HSPF Simulated Flow Observed Flow Gage REACH OUTFLOW FROM DSN 103 4.84-Year Analysis Period: 3/1/1995 - 12/31/1999 Hydrologic Unit Code: 17110014 Flow volumes are (inches/year) for upstream drainage area Latitude: 47.19760016 This version has fix to hydrograph separation Longitude: -122.337343 Drainage Area (sq-mi): 13 Total Simulated In-stream Flow: 66.43 Total Observed In-stream Flow: 67.06 Total of simulated highest 10% flows: 10.21 Total of Observed highest 10% flows: 10.01 Total of Simulated lowest 50% flows: 27.42 Total of Observed Lowest 50% flows: 28.25 Simulated Summer Flow Volume (months 7-9): 14.72 Observed Summer Flow Volume 15.50 Simulated Fall Flow Volume (months 10-12): 17.68 Observed Fall Flow Volume (10-12): 18.45 Simulated Winter Flow Volume (months 1-3): 17.22 Observed Winter Flow Volume 16.26 Simulated Spring Flow Volume (months 4-6): 16.80 Observed Spring Flow Volume 16.85 Total Simulated Storm Volume: 3.30 Total Observed Storm Volume: 2.79 Simulated Summer Storm Volume 0.20 Observed Summer Storm Volume 0.26 Errors (Simulated-Observed) Error Statistics Recommended Criteria Error in total volume: -0.94 10 Error in 50% lowest flows: -2.94 10 Error in 10% highest flows: 1.95 15 Seasonal volume error - Summer: -5.05 30 Seasonal volume error - Fall: -4.18 30 Seasonal volume error - Winter: 5.92 30 Seasonal volume error - Spring: -0.25 30 Error in storm volumes: 18.52 20 Error in summer storm volumes: -21.90 50 Nash-Sutcliffe Coefficient of Efficiency, E: 0.699 Model accuracy increases NSE 0.950 as E approaches 1.0 USGS 12102075 CLARKS CREEK AT TACOMA ROAD NEAR PUYALLUP, WA 0 50 100 150 200 250 10/1/07 10/11/07 10/21/07 10/31/07 11/10/07 11/20/07 11/30/07 12/10/07 12/20/07 12/30/07 Simulated Gage ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 6-17 In contrast, results for fall 2003 are shown in Figure 6-20 and reveal several anomalies. Most notably, an extremely large flow is predicted for October 8, 2003, whereas the gage shows almost no response on that date. The large predicted flow is due to the precipitation record, as the WSU Puyallup station reported 4.85 inches total rainfall for this date. If correct, this would be an extraordinarily large rainfall event for the area. However, the reported data are suspect: On this date, the Seatac airport station reported only 0.27 inches, while the McMillin Reservoir gage reported about 0.3 inches. Thus, the WSU record for this day may be incorrect. Figure 6-20. Hourly Flow Prediction for Clarks Creek at Tacoma Rd., Fall 2003 Note: Precipitation data appear to be incorrect for 10/8/2003. Figure 6-20 also shows an actual major event on October 20 – October 21, 2003. This storm caused approximately $800,000 damage and set record daily rainfall totals at Seatac Airport, Olympia, and other locations according to NOAA event record details (http://www4.ncdc.noaa.gov/cgi- win/wwcgi.dll?wwevent~ShowEvent~521417). In Pierce County, 5.7 inches of precipitation was recorded at McMillin Reservoir on this date and 3.7 inches at WSU, with approximately another 0.5 inches on the following day. The model appears to overpredict the results from the gage, which had a daily average flow of only 138 cfs and a peak of 165 cfs on 10/21. However, instantaneous flow measurements made at 56th Street during water quality sampling reported 279 cfs on this day, in line with the model predictions. If both gage records are accurate this storm may have been spatially heterogeneous, with more intense rainfall on the portions of Clarks Creek. 6.6 COMPARISON TO ADDITIONAL FLOW INFORMATION Limited instantaneous flow measurements are available at locations other than Tacoma Road. Between 1981 and 1997, 41 field measurements of flow are reported by USGS for Clarks Creek at the mouth (gage 12102100). For the period 2006-2008, USGS has also taken 9 field measurements on Clarks Creek at Puyallup (gage 12102000, located at the upstream end of Clarks Creek Park; this was also monitored continuously from March 1946 to May 1948) and two field measurements from Clarks Creek at 7th Ave. SW (gage 12102010). USGS also reports 12 measurements at the mouth of Rody Creek (12102050). Additional instantaneous flow measurements at multiple locations on Clarks Creek and tributaries were taken during the 2002-2003 water quality sampling used to develop the fecal coliform TMDL (WA ECY, 2008), including measurements on several of the tributaries. The USGS flow measurements were obtained using standard, quality assured methods, and are mostly rated by USGS as of only fair accuracy. The additional 2002-2003 flow data are based on rating curves developed from a limited number of measurements and no detailed quality assessments are available. These data should be considered as of unknown accuracy. The most extensive and likely most reliable of these additional series are those associated with the USGS stations at the mouth of Clarks Creek and Rody Creek (Figure 6-21), although these are instantaneous 0 100 200 300 400 500 600 700 800 10/1/03 10/11/03 10/21/03 10/31/03 11/10/03 11/20/03 11/30/03 12/10/03 12/20/03 12/30/03 Simulated Observed ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 6-18 rather than daily average measurements. Note that the non-USGS measurements on Rody were not obtained at exactly the same location as the USGS measurements. Figure 6-21. Comparison of Observed and Simulated Flows for Clarks Creek at Mouth and Rody Creek (cfs) Note: Non-USGS measurements are shown with a green halo; simulated flows are daily averages, observed flows are instantaneous measurements. The agreement between observations and predictions appears reasonable, particularly given that the observations are instantaneous. The average error at the mouth is 8.03 percent, while that on Rody Creek is 15.35 percent. Comparisons at eight additional stations are shown in Figure 6-22. The model appears reasonable. Some individual events appear to be under-predicted, but this is likely due to the 2002-2003 instantaneous measurements targeting peak storm flows. 0 50 100 150 200 250 300 350 1/1/1981 1/1/1985 1/1/1989 1/1/1993 1/1/1997 Flow (cfs) Clarks Creek at Mouth (USGS 12102100) 0 5 10 15 20 25 30 35 40 1/1/1990 1/1/1994 1/1/1998 1/1/2002 1/1/2006 Flow (cfs) Rody Creek (USGS 12102050, RURS1) ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 6-19 Figure 6-22. Comparison of Observed and Simulated Flows for Miscellaneous Clarks Creek Measurements (cfs) Note: Non-USGS measurements are shown with a green halo; simulated flows are daily averages, observed flows are instantaneous measurements. 0 5 10 15 20 25 30 35 40 45 50 1/1/2002 1/1/2003 Flow (cfs) Clarks Creek Park above Hatchery (CURS5) 0 50 100 150 200 250 300 350 1/1/2002 1/1/2004 1/1/2006 1/1/2008 Flow (cfs) Clarks Creek at 7th Ave. (USGS 12102010, CURS3) 0 50 100 150 200 250 1/1/2002 1/1/2003 Flow (cfs) Clarks Creek below Pioneer (CURS2) 0 50 100 150 200 250 300 350 400 450 1/1/2002 1/1/2003 Flow (cfs) Clarks Creek at 56th (CURS1) 0 5 10 15 20 25 30 35 40 45 1/1/2002 1/1/2003 Flow (cfs) Diru Creek (DURS1) 0 10 20 30 40 50 60 70 80 1/1/2002 1/1/2003 Flow (cfs) Woodland Creek (WURS1) 0 20 40 60 80 100 120 140 1/1/2002 1/1/2003 Flow (cs) Meeker Creek (MDURS1) 0 5 10 15 20 25 30 35 40 1/1/2002 1/1/2003 Flow (cfs) Upper Meeker (MDURS2) ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 6-20 Additional flow observations are available in the area of the State Hatchery (USGS 12102000 and CURS4). The stations appear to be not exactly coincident, although the location given for the 2002-2003 station (CURS4) is uncertain as the coordinates do not fall on the streamline. Both are in the general neighborhood of the overflow releases from Maplewood Springs and the return flow from the hatchery, but the exact spatial relationship is unclear. This is also an area where significant amounts of spring flow enter the stream from the foot of the Vashon Till. The two gages are in the middle of HSPF reach 135, so also are not exactly matched to the model. USGS measurements at this location fall below model predictions, while the 2002-2003 measurements at CURS4 tend to be higher (Figure 6-23). These discrepancies are likely related to the location of the gage sites relative to the complex inflows in this reach. Figure 6-23. Flow Measurements in Vicinity of State Hatchery Note: Blue line shows model predictions for Reach 134. Grey area shows range from upstream Reach 135 to reach 133. Non-USGS measurements are shown with a green halo; simulated flows are daily averages, observed flows are instantaneous measurements. 0 10 20 30 40 50 60 70 80 Flow (cfs) Clarks Creek Park below Hatchery (USGS 12102000; CURS4) ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 7-1 7 Sediment Calibration and Validation The HSPF model has the capability to simulate a variety of processes related to sediment and solids transport. On pervious and impervious upland areas the model simulates a single bulk solids class, subject to some or all of the following processes:  Detachment of sediment from pervious surfaces by rainfall splash or human influences (as a function of rainfall intensity, cover, soil characteristics, and management practices).  Accumulation of solids on impervious surfaces.  Wind deposition of solids on pervious and impervious surfaces.  Reattachment of solids into the soil matrix or removal of solids from impervious surfaces by wind, street cleaning, or other mechanisms.  Washoff of detached solids to receiving streams as a function of surface flow depth.  Scour of the soil matrix by concentrated flow (gully formation). The bulk solids simulated on the uplands are converted to three size fractions (sand, silt, clay) when load enters the receiving water. This is a user specification: the model does not compute size fractions on the upland or calculate enrichment of fines during transport. Within the stream network, the model simulates the three size classes separately, performing mass balances in both the water column and stream bed. Solids in the stream are subject to the following processes:  Advective transport.  Settling and deposition to the stream bed at lower flows as a function of flow velocity (for non- cohesive sand) or shear stress (for cohesive silt and clay).  Scour from the stream bed and bank at higher flows as a function of flow velocity (for non- cohesive sand) or shear stress (for cohesive silt and clay).  Point source load additions. A stream reach is represented as a fully mixed segment and the model does not contain detailed geometry of the channel at the within-reach scale, so the resolution of processes is limited to the scale of reach. The model thus simulates aggradation and degradation of stream reaches in an approximate, summary manner that is appropriate to a watershed scale mass balance, but does not identify the exact location of aggradation and degradation processes in specific stream reaches. 7.1 SEDIMENT CALIBRATION APPROACH Calibration of watershed sediment models is complex because instream observations of TSS are the net result of a variety of complex processes, including sediment detachment on the uplands, transport of detached sediment from the land surface to streams, and bank erosion, scour, and deposition within the streams. In addition, data for calibration are often limited – certainly the case for Clarks Creek. As a result, there is often not a unique solution to model calibration, as, for example, high concentrations observed in stream could result from elevated upland loads and/or sediment scour within the channel. These two sources are not readily distinguished through observations unless auxiliary information (such as radionuclide data) is collected to identify the fraction of stream sediment that has been in recent contact with the atmosphere. An additional challenge for sediment calibration is that sediment concentrations often vary rapidly over short time intervals. For instance, the first flush phenomenon can result in TSS concentrations that spike up in the rising limb of the storm hydrograph, then decline. Instantaneous grab samples may provide little ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 7-2 information on the daily average sediment concentration, while sub-daily model predictions and observations for the same time interval may show large discrepancies if there are small differences in the timing of predicted and observed flows. Flow-weighted composites over the storm hydrograph are most informative. For Clarks Creek, most available TSS samples are grab samples – and the time of collection is not available for most of the samples. The recourse is to compare these point-in-time samples to daily average concentrations produced by the model and attempt to obtain a representation that is unbiased over the long term, recognizing that there will be significant discrepancies between some individual observations and model predictions. The approach undertaken for sediment calibration follows the guidance of USEPA (2006) and Donigian and Love (2003). The general strategy for sediment calibration of the Clarks Creek model, following Donigian and Love (2003), consists of the following steps:  Specify initial upland parameter values for soil erodibility (detachment rates) on pervious land and soil accumulation rates on impervious surfaces based on external information soils data, literature).  Adjust upland sediment transport rates from individual land uses to achieve general consistency with annual sediment loading rates reported in the literature (preferably from local studies).  Analyze the instream sediment mass balance on a reach by reach basis to ensure reasonable representation of areas of scour and deposition.  Adjust instream/channel parameters to match observed total suspended solids (TSS) concentrations and loads. Each of these steps is described below. 7.2 UPLAND PARAMETER SPECIFICATION Parameters controlling the erodibility of the soil are specified based on soil properties. The HSPF model does not use the Universal Soil Loss Equation (USLE) for sediment simulation; however, some of the parameters used in HSPF are similar to those in the USLE. The USDA State Soils (SSURGO) database provides a number of USLE parameter estimates by soil type, and these can be used to set initial parameter values – ensuring relative consistency between the HSPF and USLE approaches. HSPF erosion parameters for pervious land uses were estimated based on a theoretical relationship between HSPF algorithms and documented soil parameters, ensuring consistency in relative estimates of erosion based on soil type and cover. Sediment is available for transport once it is detached from the soil matrix. HSPF calculates the detachment rate of sediment by rainfall energy (in tons/acre) as JRER P KRER SMPF COVER DET      ) 1( where DET is the detachment rate (tons/acre), COVER is the dimensionless factor accounting for the effects of cover on the detachment of soil particles, SMPF is the dimensionless management practice factor, KRER is the coefficient in the soil detachment equation, JRER is the exponent in the soil detachment equation, which is recommended to be set to 1.81, and P is precipitation in inches. Actual sediment storage available for transport (DETS) is a function of accumulation over time and the reincorporation rate, AFFIX. The equation for DET is formally similar to the USLE equation (Wischmeier and Smith, 1978) where RE is the rainfall erosivity, K is the soil erodibility factor, LS is the length-slope factor, C is the cover factor, and P is the practice factor, RE · K · LS · C · P. ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 7-3 USLE predicts sediment loss from one or a series of events at the field scale, and thus incorporates local transport as well as sediment detachment. For a large event with a significant antecedent dry period, it is reasonable to assume that DET≈DETS if AFFIX is greater than zero. Further, during a large runoff event, sediment yield at the field scale is assumed to be limited by supply, rather than transport capacity. Under those conditions, the USLE yield from an event should approximate DET in HSPF. With these assumptions, the HSPF variable SMPF may be taken as fully analogous to the USLE P factor. The complement of COVER is equivalent to the USLE C factor (1 - COVER) = This leaves the following equivalence (given JRER = 1.81): LS K RE P KRER JRER     , or 81 .1 P LS K RE KRER    The empirical equation of Richardson et al. (1983) as further tested by Haith and Merrill (1987) gives an expression for RE (in units of MJ-mm/ha-h) in terms of precipitation: 81 .1 6. 64 R a RE t    where R is precipitation in cm and at is an empirical factor that varies by location and season. As shown in Haith et al. (1992), the expression for RE can be re-expressed in units of metric tons/ha as: 81 .1 6. 64 132 .0 R a RE t     This relationship suggests that the HSPF exponent on precipitation, JRER, should be set to 1.81. The remainder of the terms in the calculation of RE must be subsumed into the KRER term of HSPF, with a units conversion. Writing RE in terms of tons/acre and using precipitation in inches:   ) / 24 .2 / 1( ) / 54 .2 ( ) ( 6. 64 132 .0 ) / ( 81 .1 81 .1 ha tonnes ac ton in cm in P a ac tons RE t       The average value for at for this part of Washington is about 0.18 (Selker et al., 1990), yielding 81 .1 7032 .3 P RE   The power term for precipitation can then be eliminated from the equation for KRER, leaving the following expression (English units) in terms of the USLE K factor: LS K KRER    7032 .3 The K factor is available directly from soil surveys, while the LS factor can be estimated from slope, using the expression of Wischmeier and Smith (1978):     065 .0 sin 56 .4 sin 41 . 65 045 .0 2     k k b L LS   , where θ = tan-1 (S/100), S is the slope in percent, L is the slope length, and b takes the following values: 0.5 for S ≥ 5, 0.4 for 3.5 ≤ S < 5, 0.3 for 1 ≤ S < 3, and 0.2 for S < 1. This approach establishes initial values for KRER that are consistent with USLE information. It should be noted that Donigian and Love (2003) recommend setting KRER directly equal to the USLE K factor. As can be seen from the discussion above, this is theoretically incorrect, although KRER will be proportional to K, depending on slope. Other soil erosion parameters were assigned based on land use. The SMPF factor is typically used to describe row crop agricultural management practices, and was left at 1 for all land uses in the watershed except agriculture, where a value of 0.75 was assigned, representing approximately 50 percent adoption ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 7-4 of erosion reduction BMPs. COVER was assigned to PERLND as the complement of the USLE C factor, estimated on a basis. Basic C factors were assigned according to Novotny and Chesters (1981). Evidence was not available to support a detailed analysis of gully formation outside the stream network, although this can be a significant source of sediment load. The gully routines were turned on for the highest-sloped forest land segments. For impervious surfaces (including roads), availability of solids is simulated with a buildup-washoff formulation, which requires an accumulation rate (ACCSD) and a removal rate (REMSDP). The steady-state limit of storage mass (under conditions of no washoff) is equal to the accumulation rate divided by the removal rate. Initial values were set based on literature and experience (Table 7-1). Accumulation rates are set to vary within a relatively narrow range from 0.01 tons/ac/day to 0.02 tons/ac/day, with higher rates for high density urban land uses, consistent with studies summarized in USEPA (2006) and Novotny and Olem (1994). Removal rates for most land uses are set at 0.04 per day, in the typical range recommended by USEPA (2006). Higher removal rates are set for roads. On transportation arteries significant removal is caused by wind turbulence caused by passing cars, while many urban streets are subject to mechanical street cleaning. While empirical relationships have been developed to describe the effect of traffic density, curb height, and street cleaning frequency on removal rates for solids (Novotny and Olem, 1994), such data were not readily available for the Clarks Creek watershed. Table 7-1. Sediment Buildup Parameters for Impervious Lands Impervious Land Use Accumulation t/ac/day) Removal (REMSDP; day-1) High density developed 0.020 0.040 Medium density developed 0.015 0.040 Low density developed 0.015 0.040 Road (till area) 0.012 0.100 Road (alluvial areas) 0.012 0.100 Park 0.010 0.040 Washoff of sediment from high and medium density impervious areas was simulated with sediment option SDOP=0, which calculates transport capacity as a function of depth of flow, not depth of flow plus surface storage. Use of this option is essential for impervious surfaces in Clarks Creek because surface storage is being used to approximate partial stormwater detention, as described in Section 4.4, and this storage should not be included in transport capacity. 7.3 SEDIMENT TRANSPORT TO STREAM HSPF simulates transport of detached sediment as a function of overland flow depth, controlled by a coefficient (KSER) and an exponent (JSER) on flow depth. The exponent, JSER, was set to the recommended value of 1.67, while the coefficient, KSER, was adjusted to obtain a reasonable representation of average annual solids loading by land use (as a function of hydrology) while also providing an amount of suspended solids load consistent with instream observations. One useful reference from western Washington is the Green-Duwamish study in King Co. (Herrera, 2007). This reports average annual loading rates from low-to-medium-density development of 0.07 tons/ac/yr and from high density development of 0.077 tons/ac/yr. Herrera also reports suspended solids load from agriculture that seem low (0.0215 t/ac/yr) and from forest that seem high (0.0489 t/ac/yr), but may reflect the specific circumstances of their monitoring watersheds. Intact forest can often have much lower loading rates, whereas agriculture with poorer management practices can have significantly higher loads. ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 7-5 Notably, Herrera’s forest tributaries were about 90 percent forest, with the remainder including roads, grass, and some development, which could account for a majority of the load. The Clarks Creek model separates intact forest from these other land uses and is expected to have low unit area loading rates. National data on solids loads from roads provide averages mostly in the range of 0.14 to 2 t/ac/yr (Driscoll et al., 1990), with the higher loads tending to occur in areas that combine high traffic with high amounts of wind-blown dust deposition. The average simulated loading rates for the Clarks Creek watershed are thus expected to fall at the lower end of this range. A reasonable representation of sediment yield by land use was obtained by setting a uniform value of the pervious land sediment transport coefficient KSER at 10.0 while varying the impervious land transport coefficient KEIM from 0.054 to 0.065, with the higher values specified for roads, which are generally designed for efficient water removal. The resulting upland sediment yield rates are summarized in Figure 7-1. Figure 7-1. Average Annual Sediment Yield by Land Use Note: Unweighted averages across all soils and slopes are shown for comparison to literature values. Impervious area percentages are assumed to be 5% for low density development (LDEV), 20% for medium density development (MDEV), 45% for high density development (HDEV), and 67% for roads for purposes of comparison. HSPF simulates total sediment on the uplands, but represents sand, silt, and clay separately in the stream reaches. Assignment to these classes is made in the MASS-LINK block, which routes the upland load to the stream. Across the whole watershed, the area-weighted composition of surficial sediment is 48 percent sand, 40 percent silt, and 11 percent clay based on the SSURGO soil survey coverage. Sediment detachment and transport processes, however, result in a progressive enrichment of the finer fractions and proportionately less transport of the heavier sand fraction. Because the probability of redeposition of clays during overland transport is very small, Walling (1983) showed that the enrichment ratio for clay is approximately equal to the inverse of the delivery ratio (and thus should vary by subbasin size). For the small subbasins in the Clarks Creek model, an initial estimate of a delivery ratio as a function of area of around 30 percent is reasonable based on Roehl (1962); thus the clay fraction was increased from 11 to 37 percent and the silt fraction from 40 to 45 percent, leaving 18 percent sand. Note that even though loading may be enriched in fines much of the sediment bed is made up of sand. This occurs because the clay and much of the silt wash through the stream without settling out. 0.000 0.008 0.008 0.052 0.030 0.05 0.07 0.11 0.17 0.00 0.02 0.04 0.06 0.08 0.10 0.12 0.14 0.16 0.18 0.20 Average Sedt Yld (t/ac/yr) ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 7-6 7.4 REACH SEDIMENT SETUP Complex cycles of deposition and scour occur in stream reaches, determined by the shear stress exerted on the bed material and the external sediment supply. The model simulates deposition and scour (aggradation and deposition) of silt and clay in stream reaches based on exerted shear stress relative to critical shear stresses for deposition and scour (τCD and τCS) for each sediment size class, particle deposition velocities, and a limiting maximum potential rate of scour lb/ft2/d). The parameters τCD, τCS, and W are site-specific and vary by reach. (HSPF is a spatially lumped model, with stream reaches represented as fully mixed, and the simulated boundary shear stress represents reach-averaged conditions, while actual shear varies continuously based on local characteristics of the channel. As the processes are non-linear, a single set of parameters will not adequately represent the behavior of bed sediment in all reaches; instead, these should be set on a reach-by-reach basis.) For the non-cohesive, sand fraction of sediment, HSPF provides several options, including the Toffaletti method, the Colby method, and a simplified exponential relationship to flow. The Toffaletti and Colby methods are most appropriate for wide sand-bed rivers and additionally can cause stability problems in the model, so the third (exponential equation) approach is used for Clarks Creek. In this approach sand transport capacity is a function of KSAND · AVVELE where AVVELE is the average velocity and KSAND and are user-specified parameters. Following the advice of Donigian and Love (2003) and USEPA (2006), critical shear stresses for cohesive sediments were initially set to percentiles of the overall shear (Tau) distribution, which is closely tied to flow (Figure 7-2). Specifically, τCD was set at the 25th and 20th percentiles of the distribution, for silt and clay, respectively, while τCS was set at the 95th and 90th percentiles for silt and clay. This allows scour to occur only at higher flows, with clay scouring prior to silt. Model predictions of scour at high flows are sensitive to these values; however, sufficient monitoring data of extreme events is not available to refine these values further. Figure 7-2. Example Relationship between Tau and Flow, Reach 135 Simulation of channel scour and deposition must provide a reasonable mass balance in the stream reaches in addition to matching observed TSS concentrations. The total change in simulated nominal bed depth over the 51-year simulation period is summarized by reach in Figure 7-3. (This is a “nominal” rather than actual change because HSPF represents the reaches in a simplified, one-dimensional manner). As seen in this figure, most stream reaches remain approximately stable over time. Degradation (decrease in bed depth) is simulated primarily in reaches that intersect the face of the Vashon Till (134 on the mainstem, 128 on Silver Creek, 147 on Woodland Creek, 157 on Diru Creek, and 166 on Rody Creek), while aggradation is simulated in the most reaches of Woodland, Diru, and Rody, and in the mainstem after in enters the alluvial plain of the Puyallup River. 0 1 2 3 4 1 10 100 Tau (lb/ft2) Flow (cfs) REACH 135 ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 7-7 Figure 7-3. Simulated Change in Bed Depth by Model Reach, 1960-2010 Note: Depth changes are relative measures of scour/deposition in a one-dimensional reach model, 7.5 INSTREAM SEDIMENT CALIBRATION The full sediment model is calibrated through comparison to observed total suspended solids concentrations by adjusting the parameters that control the scour and deposition of sand, silt, and clay (as well as by adjusting the upland transport simulation.) Suspended solids observations are available at multiple stations, but the number of samples at individual stations is limited. The calibration period was selected as the more data rich period of 2002 – 2010, while earlier data were used for validation. Unfortunately, the desired minimum sample size of 20 observations is attained at only a few of the stations. Accordingly, a weight of evidence approach was used, for which model fit statistics are supplemented with a variety of graphical comparisons. It should be noted that a technical limitation of the HSPF model creates potential problems for fitting to observed concentrations in very small streams. Specifically, HSPF subroutine BDEXCH turns off the simulation of cohesive sediment scour and deposition when reach average depth falls below 0.17 ft (2 inches), where average depth is defined as the reach volume divided by the surface area. This is designed to prevent model instability. With the exception of the mainstem of Clarks Creek of Maplewood Springs, most reaches in the model experience average depths that are less than 0.17 ft at least some of the time. During these periods settling of silt and clay is not simulated; instead, both are transported through the reach unchanged, whereas in fact significant settling is likely to occur during such low flow conditions. This limits the model’s ability to reproduce low flow observations, including observations in the mainstem that are affected by simulated concentrations in smaller tributaries. This is not a significant problem, however, as the load transported at low flows will be small and will not contribute significantly to solids concentrations and loads in the Clarks Creek mainstem. Figure 7-4 through Figure 7-7 show sediment calibration results at four stations on Clarks Creek mainstem, arranged in order. For each of these observation points the model predicts the range of TSS observations reasonably well, although not all individual observations are matched. The lowest observations (less than 2 mg/L) are over-estimated at 7th Street and 12th Street primarily due to an assumption that low levels of fines are associated with the baseflow from springs in the upper reaches of the creek (1 mg/L above the State Hatchery and 2 mg/L below). These constant concentration assumptions (which represent a typical background condition due to factors such as animal activity as well as any fine sediment actually discharged or eroded at the spring outfalls) fit the majority of the data, but over-predict some individual low-flow measurements. -1.5 -1 -0.5 0 0.5 1 1.5 2 101 104 107 110 113 116 119 122 125 128 131 134 137 140 143 146 149 152 155 158 161 164 167 170 203 Change in Depth (ft) ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 7-8 Figure 7-4. Time Series Comparison for TSS, Clarks Creek above State Hatchery, 2002-2010 Note: Data shown are for stations CCURS-5 and Clk-4 Figure 7-5. Time Series Comparison for TSS, Clarks Creek below State Hatchery, 2002-2010 Note: Data shown are for station CCURS-2 0.1 1 10 100 1000 2002 2003 2004 2005 2006 2007 2008 2009 TSS, mg/L Year CC above Hatchery (R135) Simulated Observed 0.1 1 10 100 1000 2002 2003 2004 2005 2006 2007 2008 2009 TSS, mg/L Year CC below Hatchery (R134) Simulated Observed ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 7-9 Figure 7-6. Time Series Comparison for TSS, Clarks Creek at 12th St. Bridge, 2002-2010 Note: Data shown are for station Clk-8 Figure 7-7. Time Series Comparison for TSS, Clarks Creek above 7th Street, 2002-2010 Note: Data shown are for station CCURS-3 0.1 1 10 100 1000 2002 2003 2004 2005 2006 2007 2008 2009 TSS, mg/L Year CC 12th St Br (R133) Simulated Observed 0.1 1 10 100 1000 2002 2003 2004 2005 2006 2007 2008 2009 TSS, mg/L Year CC above 7th (R114) Simulated Observed ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 7-10 The calibration procedure is illustrated in more detail for the station on Clarks Creek at 66th Street. In addition to standard time series plots (Figure 7-8), power plots of load and concentration versus flow were used to ensure that the model and data show similar relationships (Figure 7-9). Plots of prediction error versus month and flow are used to check whether there are significant trends with season or flow magnitude, recognizing that considerable variability is expected from the comparison of grab samples to daily averages. For this station (Figure 7-10 and Figure 7-11), the errors are relatively evenly distributed against month (it could be contended that December TSS is over-estimated, but the sample size is small). Distribution of errors versus flow also does not show any strong bias. Observations appear to be somewhat over-predicted at high flows, but this may be a result of small differences in timing and the comparison of model daily averages to grab samples. In addition, the HSPF representation of reaches cannot distinguish between bedload and suspended load and will thus overpredict observations of TSS if a significant fraction of solids is moving as bedload and is not represented in water column grab samples. Figure 7-8. Time Series Comparison for TSS Calibration, Clarks Creek at 66th Street, 2002-2010 Note: Data shown are for stations CLK-4.1, Clk-4, and CCURS-1. 0.1 1 10 100 1000 2002 2003 2004 2005 2006 2007 2008 2009 TSS, mg/L Year Clarks Creek at 66th Street (R104) Simulated Observed ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 7-11 Figure 7-9. Power Plots of TSS Load and Concentration versus Flow, Clarks Creek at 66th Street, 2002-2010 Figure 7-10. TSS Prediction Error versus Month, Clarks Creek at 66th Street, 2002-2010 0.0001 0.001 0.01 0.1 1 10 100 1000 10 100 1000 TSS Load, tons/day Flow, cfs Clarks Creek at 66th Street (R104) 2002-2010 Simulated Observed 0.1 1 10 100 1000 1 10 100 1000 TSS, mg/L Flow, cfs Clarks Creek at 66th Street (R104) 2002-2010 Simulated Observed -60 -40 -20 0 20 40 60 80 0 2 4 6 8 10 12 TSS Concentration Error, mg/L Month ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 7-12 Figure 7-11. TSS Prediction Error versus Flow, Clarks Creek at 66th Street, 2002-2010 Further examination of TSS prediction errors at 66th Street suggest that much of the uncertainty in storm flow concentration predictions could be due to small errors in timing. The observations are point-in-time grab samples that are likely to vary rapidly in time due to pulses from the nearby storm drains. Comparison is shown above to daily average model output as the majority of data do not show time of sample collection. Even if time of collection is available, small shifts in phase between the model and data due to reliance on a single weather station are likely to lead to relatively large discrepancies between the model and individual observations. The strong intra-day variability in predicted sediment concentrations at this station is shown in a detailed examination of December 2002 results (Figure 7-12). Figure 7-12. Hourly Variability in Predicted Sediment Concentration, Clarks Creek at 66th Street, December 2002 Additional data, mostly from 2002-2003, are available at the mouths of Meeker, Rody, and Diru Creeks. Calibration statistics for TSS are presented in Table 7-2. Most of the stations either do not meet the -60 -40 -20 0 20 40 60 80 10 100 1000 TSS Concentration Error, mg/L Flow, cfs 0 10 20 30 40 50 60 70 80 90 12/1/02 12/6/02 12/11/02 12/16/02 12/21/02 12/26/02 12/31/02 Simulated Observed ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 7-13 minimum data requirement for quantitative analysis of 20 samples (see Section 5.2), or exceed it by a small amount. This leaves the results open to undue influence by outliers. This can be mitigated by examining median rather than average relative errors. Good or very good results are obtained for most stations and high average relative errors are mostly attributable to outliers. For example, at the 12th Street monitoring site, the large average relative error is mostly due to a large error associated with the event of 10/8/2003 when the model predicted a daily average of 145 mg/L, but the observation showed only 3 mg/L. As was noted in Section 6.5, the extreme precipitation recorded for this day may be in error. Results for Clarks Creek above the State Hatchery should be viewed in light of the observation that flow is often under-predicted at this site due to uncertainty as to exactly where the spring-fed baseflow enters the stream (see Figure 6-23). Therefore, the over-estimation, on average, of TSS at this location is not unexpected. The limited sampling at the mouths of Meeker, Rody, and Diru Creeks and upstream on Meeker Creek is also affected by occasional outliers and mistiming of event peaks, although the overall results appear consistent with the observations. Further, the simulated concentrations in Meeker, Rody, and Diru are consistent with the observed concentrations just in Clarks Creek at 66th Street. Table 7-2. Calibration Statistics for Total Suspended Sediment, 2002 – 2010 Station Observation Count Mean Observed (mg/L) Average Relative Error Median Relative Error Clarks Creek at 66th Street 25 15.03 -21.7% -8.6% Clarks Creek above 7th Street 12 9.00 6.9% -7.6% Clarks Creek at 12th Street 32 4.48 70.4% -7.2% Clarks Creek below State Hatchery 12 8.17 17.4% -0.8% Clarks Creek above State Hatchery 18 4.26 152.3% 3.7% Meeker Creek mouth 12 28.61 1.7% -6.8% Meeker at Reach 123 11 43.98 -27.0% 5.6% Rody Creek mouth 11 30.67 -6.1% -2.1% Diru Creek mouth 11 14.02 51.3% 4.0% Note: Relative errors are calculated as simulated minus observed normalized to the observed mean. In sum, data for model calibration to TSS are limited; however, the model appears to perform adequately in predicting the available data. Sample sizes are small and easily influenced by a few outliers. The model does represent both the temporal and spatial trends in observed TSS. 7.6 SEDIMENT MODEL TESTING The greatest amount of data is for 2002-2003, so observations from 2002 on were used for model calibration. Data from the period prior to 2002 was not used for calibration but reserved for additional testing of the sediment model. Ordinarily, this would be termed a validation test. Unfortunately, sample ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 7-14 sizes for this period are small, with the maximum number of available samples at a single station being nine. Therefore, examination of model predictions for this period is treated as a more qualitative corroboration test. Nonetheless, the general performance of the model for this period appears reasonable. Note that some of the samples collected at 66th Street prior to 2002 were apparently of the Tribal hatchery rearing pond discharge, whereas later samples were upstream, which may help explain the results at that station. Table 7-3. Validation Statistics for Total Suspended Sediment, 1996 – 2001 Station Observation Count Mean Observed (mg/L) Average Relative Error Median Relative Error Clarks Creek at 66th Street 7 8.36 60.0% 43.4% Clarks Creek above 7th Street 0 ND ND ND Clarks Creek at 12th Street 3 4.63 47.7% 32.1% Clarks Creek below State Hatchery 8 11.21 -28.2% -8.5% Clarks Creek above State Hatchery 9 34.6 -72.2% 1.8% Meeker Creek mouth 5 123.78 -84.4% -6.4% Meeker at Reach 123 3 2.30 267.0% 348.7% Rody Creek mouth 0 ND ND ND Diru Creek mouth 0 ND ND ND 7.7 SEDIMENT LOAD SOURCES The Clarks Creek model simulation indicates that most flow from pervious surfaces proceeds by interflow and groundwater pathways, rather than direct surface runoff. As a result, the majority of sediment load is simulated as coming from impervious surfaces (although much of this load will actually arise at the interface between impervious and pervious surfaces). The presence of some sediment load coming from interflow through macropores or soil “tubes” is in part accounted for by assigning a small sediment concentration to the spring discharges. The overall sediment balance for the 51-year simulation period is summarized in Table 7-4. Over the entire stream network there is a net flux to the water column from the stream bank and bed (scour minus deposition) of 17.1 tons/yr. This obscures the fact that reaches at the face of the Vashon till are simulated as having substantial degradation. Degrading reaches are estimated to export a total of 103 tons/yr of sediment to the system, on average. ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 7-15 Table 7-4. Clarks Creek Sediment Balance for 1960-2010 Simulation Source Sediment Load (tons/yr) Upland Sources (load to stream network) 459.8 Baseflow Sources (assigned to spring inflows) 104.0 Net Channel Processes 17.1 Outflow to Puyallup River 581.0 Over the whole watershed (excluding reach 301, where most flow and load is diverted to the Puyallup River by the WSDOT flow splitter), the largest source of sediment is runoff from the uplands. Details of the source of this load are shown in Table 7-5. These reflect generally low loading rates for pervious surfaces (and small areas associated with the agriculture and pasture land uses). High density development (which accounts for 13.3 percent of the land area in the watershed) is estimated to provide 30.5 percent of the total upland sediment load – largely because it contains 40 percent of the impervious area in the watershed. This suggests that strategies to reduce sediment load could focus on areas of more dense development. However, the mainstem of Clarks Creek is also strongly influenced by channel degradation in the area near and above the State Hatchery, estimated by the model to contribute about 42 tons/yr on average. Analysis of tributary contributions to the Clarks Creek mainstem (Table 7-6) suggests that Meeker Creek is the largest tributary contributor of sediment load. The high rates of load suggested by Table 7-6 for Woodland Creek may be an over-estimate as filtering in the wetland reported to be present at the confluence of Woodland Creek and Clarks Creek is not explicitly accounted for in the model. Table 7-5. Upland Sediment Load Sources for 1960-2010 Simulation Land Use Average Total Load to Streams (tons/yr) Forest 6.6 Agriculture and Pasture 6.7 High Density Development 140.4 Medium Density Development 53.8 Low Density Development 40.3 Roads 146.3 Parks 65.6 ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 7-16 Table 7-6. Major Tributary Contributions to Sediment Load to Clarks Creek Mainstem Tributary Average Annual Load to Mainstem (tons/yr) Clarks Creek Mainstem above Meeker Creek 180.8 Meeker Creek 107.8 7th Street Storm Drains 28.8 Pioneer Way Storm Drains 54.2 Woodland Creek 101.8 Diru Creek 52.2 Rody Creek 46.4 7.8 EFFECTIVE WORK ANALYSIS An effective work analysis based on HSPF model simulated shear stress and geomorphic field work was conducted to estimate potential scour and depositional zones in the Clarks Creek mainstem channel. This is accomplished by combining flow and bed shear stress estimates from Tetra Tech’s HSPF hydrology model with estimates of critical shear stress for incipient motion based on bed particle characteristics of individual stream reaches provided by Brown and Caldwell1. In physics, “work” is the product of a force times the distance through which it acts and is equivalent to a measure of energy – for example, the energy required to lift a bucket of water 10 feet, or to move a ton of sand 100 yards. The rate of movement of sediment is a function of stream power, which is the product of velocity and boundary shear stress (ft/s · lb/ft2 in English units). If velocity is high but boundary shear is low, few particles will be eroded from the bed. Conversely, if shear is high but velocity is low, particles will be eroded, but little transport will occur. The sum or integral of power over time has units of work, and measures the total amount of sediment transport potential affecting a stream reach. Leopold et al. (1964) recognized that much of the total work done in erosion and transport of sediment occurs through the accumulation of events that have moderate to low power, but occur frequently. It is partly for this reason that bankfull flows (typically with a recurrence interval from 1.3 to 1.7 years) determine the cross- sectional shape of natural channels, rather than larger, more extreme events that may exhibit more power, but occur infrequently. Therefore, an analysis of the effective work done on a channel is an important indicator of channel stability – particularly for the evaluation of impacts of potential changes in hydrology. It should be noted that the available data are not sufficient to produce quantitative estimates of total erosion. Critical shear stress is based on characteristic particle size (d50) and does not reflect the full range of particles present in the bed, while shear stress time series are calculated from a one-dimensional model in which channel dimensions represent averages over model reaches. Instead, the analysis is most useful for relative evaluation. 1 Critical Shear Stress Values for Use in Effective Work Analysis, Clarks Creek Sediment Study. Memorandum from Nathan Foged, Brown and Caldwell, December 15, 2011. ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 7-17 The effective work index, W, is an integrated measure of the magnitude of work done by flows that exceed a specified critical value for the streambed. The effective work index (in work units of ft-lb/ft2) is calculated as      n i i e c i t V C W 1 ) (   , for τi > τc, where C is a units conversion constant dependent on the exponent e, n is the number of flow records, τi is the exerted boundary shear stress (lb/ft2) determined using the central channel conditions, τc is the critical shear stress that initiates bed mobility (lb/ft2), e is an exponent that captures the rise in stream power with flow (range 1.0 to 2.5), V is the mid-channel velocity (ft/s), and Δt is the duration of each flow record Note that the resulting index depends on both the frequency at which τc is exceeded and the degree of skew in the flow histogram. For the Clarks Creek analysis, e is assumed to be 1.5 (consistent with theoretical analyses of bedload transport such as Meyer-Peter-Muller), and C is ignored, as a relative comparison is the main object. Sixty years of hourly model output are available (529,960 records). To simplify the analysis, this record was sub-sampled to extract one (hourly) record per day. Results for the mainstem model segments (outlined in blue in Figure 7-13) are shown in Table 7-7. ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 7-18 Figure 7-13. Mainstem Reaches, Clarks Creek Reaches 104, 106, 107, 109, 112, 114, 133, 134,135,137, 138, and 139 constitute the Clarks Creek mainstem. 157 158 129 135 138 132 150 147 103 149 139 201 168 127 102 160 115 167 113 159 143 134 166 128 154 136 156 105 111 108 131 163 140 144 110 146 114 169 164 162 122 148 123 155 137 133 301 145 141 202 142 165 151 161 101 104 112 109 107 116 106 130 110 301 130 0 0.5 1 0.25 Miles¯ ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 7-19 Table 7-7. Effective Work Analysis for Clarks Creek Mainstem HSPF Reach Particle Diameter (d50, mm) Classification for d50 Critical Shear Stress, τc (lb/ft2) Average Velocity (ft/s) Effective Work Index, W (60-year sum) 101 5.97 Fine gravel 0.0818 1.65 5.12 · 108 104 5.97 Fine gravel 0.0818 1.10 1.36 · 108 106 0.10 Very fine sand 0.0024 1.20 2.46 · 108 107 0.09 Very find sand 0.0023 1.81 1.47 · 108 109 0.09 Very fine sand 0.0023 1.67 1.10 · 108 112 0.29 Medium sand 0.0043 0.96 4.77 · 107 114 0.22 Fine sand 0.0036 0.70 6.49 · 107 133 0.14 Fine sand 0.0028 0.73 2.52 · 107 134 4.28 Fine gravel 0.0555 1.12 3.76 · 109 135 13.57 Medium gravel 0.2034 2.08 8.77 · 109 137 4.84 Fine gravel 0.0642 14.98 3.80 · 109 138 4.84 Fine gravel 0.0642 10.80 6.53 · 108 139 4.84 Fine gravel 0.0642 8.48 1.92 · 108 The longitudinal profile of the effective work index is shown in Figure 7-14. The effective work index reaches a maximum in reach 135, the steep reach upstream of the State Hatchery in Clarks Creek Park. This is consistent with the coarse nature of the sediment in this reach which reflects the impact of cumulative work removing fines. Active scouring is likely occurring in this reach. As the stream emerges from the face of the Vashon Till onto the alluvial plain the gradient, effective work, and the diameter all decrease dramatically, suggesting areas that are primarily depositional. Effective work increases again in the most reaches, consistent with a coarsening of the sediment. Effective work curves (plotting the summed work index versus flow range bins) are most useful for examining potential channel response to changes in conditions pre- and post-development). Portions of the curve in which work increases dramatically provide an indication of the flow range that may need to be controlled to promote channel stability. Figure 7-15 shows effective work curves for existing conditions in the till area. When natural condition and full buildout runs are completed these can be used to examine potential changes in channel stability. Pre and post-development conditions can also be summarized by the Erosion Potential (MacRae, 1992), Ep, calculated as Wpost/Wpre. An Ep value greater than about 1.5 is typically a strong indicator of potential channel instability. ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 7-20 Figure 7-14. Longitudinal Profile of Effective Work Index Figure 7-15. Effective Work Curves for Reaches in the Till Area, Existing Conditions Note: Flow bins show the high value of the flow interval summarized in the graph, using 1 cfs increments up to 20 cfs. The effective work analysis shows the potential for work to be done (movement of sediment over distance) relative to the current median sediment diameter. The peak value in Reach 135 suggests that ongoing degradation of the channel is likely occurring in this reach. 0 10 20 30 40 50 60 70 80 90 100 139 138 137 135 134 133 114 112 109 107 106 104 101 W (x 1E8) Reach 0.0E+00 5.0E+08 1.0E+09 1.5E+09 2.0E+09 2.5E+09 3.0E+09 3.5E+09 1 3 5 7 9 11 13 15 17 19 25 35 W Flow Bin (cfs) R:134 R:135 R:137 R:138 ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 7-21 7.9 SENSITIVITY OF SEDIMENT MODEL RESULTS Sufficient data are not available to strongly constrain a unique solution to the simulation of sediment in Clarks Creek. Nonetheless, the model provides a reasonable description of the processes contributing to sediment load and transport within the creek, based on multiple lines of evidence. The model is useful, but not necessarily always correct. In particular, attribution of loads to specific sources is uncertain given the relatively small amount of local monitoring data. Model predictions are especially sensitive to the following assumptions:  The relative importance of loads from pervious surfaces is in large part determined by the amount of overland flow simulated from such surfaces. Flow at the only continuous stream gage in Clarks Creek (Tacoma Road) is strongly influenced by spring discharges, so the fit of model partitioning between surface and subsurface flows is subject to some uncertainty.  Loads from pervious surfaces appear to be more strongly controlled by transport capacity than by detached sediment availability. The current model is consistent with studies from the Green- Duwamish watershed in King Co.; however, detailed local monitoring could refine and improve the fit.  The majority of land area in the Clarks Creek watershed is occupied by medium density residential land uses and roads. Total sediment load predictions are thus sensitive to the loads predicted for residential and road impervious surfaces. Unlike pervious surfaces, load from impervious surfaces is more strongly controlled by solids availability than transport capacity. Thus, the model predictions are particularly sensitive to the ratio of solids accumulation to solids removal on impervious surfaces which determines the limiting concentration of solids available for transport to the stream. The current model is based on limited observations of flow and TSS. No small-scale monitoring has been conducted to estimate loads from individual land use areas. As additional data are collected it is likely that the Clarks Creek model can be improved. However, the existing model, despite uncertainties, is believed to provide a strong basis for the initial evaluation of potential sediment control options. ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 7-22 (This page left intentionally blank.) ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 8-1 8 Other Water Quality Parameters Clarks Creek is impaired due to excessive concentrations of fecal coliform bacteria and due to low dissolved oxygen concentrations that appear to be related to nutrient enrichment and overgrowth of the invasive macroalgae Elodea nuttalli. Therefore, estimates of both bacterial and nutrient/organic matter loads to the creek are of considerable importance. 8.1 WATER QUALITY MODEL SETUP Unfortunately, resources were not available to undertake full calibration of the watershed model to bacteria and nutrients at this time. As an alternative, information on land use and model simulated surface and subsurface flows by land use were combined with event mean concentrations (EMCs) obtained from a nearby watershed to estimate likely bacterial and nutrient loading. The concentrations were obtained from the Green-Duwamish watershed in King County, where detailed monitoring and analysis of concentrations and loads by land use has been conducted (Herrera, 2007). This report (Table 5-12) gives pollutant loads for different land cover types (high density developed, low- to-medium density developed, agriculture, and forest – see Table 8-1) and reports flow and loading rates separately for baseflow and event runoff conditions. Table 8-1. Green-Duwamish Loading Rates by Land Use (Herrera, 2007) Constituent Flow Component High Density Developed Low-Medium Density Agriculture Forest Inorganic N (lb/ac/yr) Baseflow 2.85 2.41 6.69 4.73 Runoff 4.82 3.03 5.00 2.23 Inorganic P (lb/ac/yr) Baseflow 0.04 0.04 0.06 0.10 Runoff 0.11 0.05 0.49 0.02 Organic P (lb/ac/yr) Baseflow 0.12 0.04 0.11 0.04 Runoff 0.32 0.15 0.21 0.11 Fecal Coliform (#/ac/yr) Baseflow 2.76E+10 6.60E+09 1.20E+09 1.40E+09 Runoff 1.12E+11 6.25E+10 4.71E+10 4.60E+09 The information in Table 8-1 was converted to event mean concentrations (EMCs) to allow portability to a different precipitation-runoff regime. For calculating EMCs for developed lands, the flow attributable to impervious surfaces was estimated as I I Q Q Q P tot I ) 1(     , where Qtot is the total unit area runoff (volume per area per year), I is the impervious fraction, QI is the unit area runoff from impervious surfaces, and QP is the unit area runoff from developed pervious surfaces, assumed to be equivalent to the runoff rate cited for agriculture (0.12 ML/ha/yr). Low-to- medium density developed land was assumed to have an effective imperviousness of 25 percent, and high density developed land was assumed to have an effective imperviousness of 75 percent. Baseflow EMCs ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 8-2 are assumed to apply to groundwater discharge, while storm event EMCs are assumed to apply to surface runoff and interflow (as most of the storm event volume simulated for Clarks Creek occurs as rapid interflow.) Finally, EMCs for pervious runoff from developed land use categories are assumed to be similar to forest, although the load is scaled up to agricultural runoff rates. The resulting EMCs are shown in Table 8-2. Note that Herrera (2007) does not provide results for total N or organic N, so only the inorganic N components (nitrate, nitrite, and ammonia nitrogen) are shown. Table 8-2. Green-Duwamish EMCs for Nutrients and Bacteria Constituent Flow Component High Density Developed Low-Medium Density Agriculture Forest Inorganic N (mg/L) Pervious Runoff 22.727 22.727 46.667 22.727 Baseflow 16.842 13.500 41.667 9.464 Impervious Runoff 10.485 15.051 NA NA Inorganic P (mg/L) Pervious Runoff 0.182 0.182 4.583 0.182 Baseflow 0.263 0.250 0.389 0.196 Impervious Runoff 0.255 0.485 NA NA Organic P (mg/L) Pervious Runoff 1.091 1.091 1.917 1.091 Baseflow 0.684 0.250 0.667 0.089 Impervious Runoff 0.727 0.798 NA NA Fecal Coliform Bacteria Pervious Runoff 4.182E+04 4.182E+04 3.925E+05 4.182E+04 Baseflow 1.453E+05 3.300E+04 6.667E+03 2.500E+03 Impervious Runoff 2.461E+05 6.526E+05 NA NA Note: “Pervious Runoff” includes both surface flow and interflow. EMCs are calculated from Table 5-12 in Herrera (2007). In addition to runoff from the land surface, a nitrate concentration of 2 mg/L is assigned to the spring outflows that feed Clarks Creek, based on data summarized by Jones et al. (1999). No pollutant loads are assigned to the two hatchery discharges: these loads are believed to be small and very little data are available. 8.2 WATER QUALITY MODEL RESULTS The EMC approach provides reasonable estimates of loading to the Clarks Creek system. It does not provide reliable concentration estimates because actual concentrations in runoff will vary with event, processes within the stream channel, such as uptake of nutrients by macrophytes or losses to the sediment are not simulated, and the water quality simulation is not calibrated. Table 8-4 shows the average annual distribution of upland load sources by land use. Of note here is the large inorganic N load attributed to “springs”. This represents the 2 mg/L nitrate-N concentration assigned to the spring-fed baseflow in Clarks Creek, as documented by Jones et al. (1999). As the flow from the springs is on the order of 40-50 cfs this represents 37 percent of the total inorganic N load. ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 8-3 Table 8-3. Upland Nutrient and Bacteria Load Sources for 1960-2010 Simulation Land Use Inorganic N (lb/yr) Inorganic P (lb/yr) Organic P (lb/yr) Fecal Coliform Forest 22,244 391 424 1.5E+07 Agriculture and Pasture 29,450 523 541 4.7E+12 High Density Development 58,657 1,322 3,785 5.5E+14 Medium Density Development 83,706 1,609 2,566 3.9E+14 Low Density Development 52,808 896 1,605 1.6E+14 Roads 62,859 1,388 3,985 5.7E+14 Parks 47,523 1,001 1,599 3.2E+14 Springs 209,058 0 0 0 The distribution of loads by tributary is provided in Table 8-4 and Figure 8-1. Note that these are summations of upland loads to a tributary, not actual loads within the tributary, which will be subject to various uptake and transformation processes. Table 8-4. Major Tributary Contributions of Nutrient and Bacteria Load to Clarks Creek Tributary Inorganic N (lb/yr) Inorganic P (lb/yr) Organic P (lb/yr) Fecal Coliform Clarks Creek Mainstem above Meeker 243,300 653 1,290 1.59E+14 Meeker Creek 61,418 1,308 2,937 4.44E+14 7th Street Storm Drains 16,048 360 760 1.27E+14 Pioneer Way Storm Drains 28,377 666 1,404 2.56E+14 Woodland Creek 77,196 1,457 3,042 3.94E+14 Diru Creek 47,070 870 1,704 2.14E+14 Rody Creek 43,242 753 1,523 1.90E+14 Note: Loads do not reflect any instream losses or retention. ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 8-4 Figure 8-1. Nutrient and Bacterial Loads by Tributary to Clarks Creek Mainstem 0 500 1,000 1,500 2,000 2,500 3,000 3,500 4,000 4,500 5,000 Above Meeker Meeker 7th Pioneer Woodland Diru Rody Total P Load (lb/yr) 0 50,000 100,000 150,000 200,000 250,000 300,000 Above Meeker Meeker 7th Pioneer Woodland Diru Rody Inorganic N Load (lb/yr) 0.00E+00 5.00E+13 1.00E+14 1.50E+14 2.00E+14 2.50E+14 3.00E+14 3.50E+14 4.00E+14 4.50E+14 5.00E+14 Above Meeker Meeker 7th Pioneer Woodland Diru Rody Fecal Coliform Load ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 9-1 9 Natural Condition and Buildout Scenarios 9.1 NATURAL CONDITIONS SCENARIO The natural conditions scenario is intended to evaluate flows and sediment loads in Clarks Creek in the absence of anthropogenic development. To do this, land use in the model was reverted to a representation of presumed natural conditions, eliminating all developed land use classes (including roads) and converting non-wetland areas back to mature forest. Note that the drainage network and channel characteristics were generally not modified for this scenario as their pre-development conditions are not well documented. The major exception is that the flow splitter that currently routes most of the flow from subbasin 301 to the Puyallup River was removed from the model. 9.2 BUILDOUT SCENARIO The buildout scenario examines the potential impacts of full buildout in the watershed. The land use for this case is obtained by converting existing undeveloped land uses to zoned land uses except where protected from development parks). This reveals the maximum amount of development and impervious surfaces that could occur in the watershed under current land use plans. The buildout land use changes the amount of directly connected impervious area in the watershed from 25 percent to 31 percent. Comparison of existing to future buildout land uses in the watersheds (Figure 9-1) shows that this scenario involves a significant amount of redevelopment from low density to medium density developed land uses. Figure 9-1. Current and Future Buildout Land Uses in Clarks Creek Watershed Ecology’s draft Phase II Municipal Stormwater Permit, Minimum Requirement “On-site Stormwater Management,” specifies Low Impact Design (LID) requirements that would apply to development SR-512 512 River Rd Meridian Ave. SR-167 Clarks Creek Watershed Model Land Use - Existing Map produced by P. Cada, 02-06-2012 NAD_1983_HARN_StatePlane_Washington_South_FIPS_4602_Feet 0 0.8 1.6 0.4 Kilometers 0 0.8 1.6 0.4 Miles Legend Model Land Use Wetlands Forest (>70% Canopy) Forest (<70% Canopy) Row Crop Pasture, Hay, Close Grown Crop High Dens. Development Medium Dens. Resid. Low Dens. Resid. Roads Park and Institutional Lands SR-512 512 River Rd Meridian Ave. SR-167 Clarks Creek Watershed Model Land Use - Future Map produced by P. Cada, 02-06-2012 NAD_1983_HARN_StatePlane_Washington_South_FIPS_4602_Feet 0 0.8 1.6 0.4 Kilometers 0 0.8 1.6 0.4 Miles Legend Model Land Use Wetlands Forest (>70% Canopy) Forest (<70% Canopy) Row Crop Pasture, Hay, Close Grown Crop High Dens. Development Medium Dens. Resid. Low Dens. Resid. Roads Park and Institutional Lands ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 9-2 projects that result in greater than 2,000 square feet of new plus replaced hard surfaces. Specifically, this says “Stormwater discharges shall match developed discharge durations to pre-developed durations for the range of pre-developed discharge rates from 8% of the 2-year peak flow to 50% of the 2-year peak flow.” If more than 5,000 square feet of hard surface is created, then Minimum Requirement #7 also applies, which requires stormwater BMPs to control flow duration from one half of the 2-year peak flow up to the 50-year peak flow. The type of stormwater controls that can be expected for future development thus depends in part on the size of projects: smaller projects would need to meet Minimum Requirement while larger requirements would need to meet both Minimum Requirement #5 and Minimum Requirement The intent of the buildout simulation is to provide a future baseline that represents a realistic worse case that is still consistent with the regulations. Some unknown portion of the new development would occur in smaller projects so that Minimum Requirement #7 would not apply. Therefore, the buildout scenario is constructed under the assumption that all new development will meet Minimum Requirement #5 (but not to provide a reasonable worst-case baseline against which to evaluate additional BMP requirements. The majority of peak runoff comes from impervious surfaces, and the difference in peak flows between developed pervious and undeveloped pervious will be much less than the difference between impervious and undeveloped pervious lands. Therefore, Minimum Requirement #5 is approximated by designing a BMP representation that controls runoff from impervious surfaces to not exceed pre-development pervious surface runoff from 8 percent of the 2-year peak flow to 50 percent of the 2-year peak flow. The BMP is represented in HSPF as a “stream reach” on a unit area basis, the hydraulic behavior of which is described in an FTable relating storage to outflow. This unit area simulation is multiplied by the area in new impervious surfaces draining to each stream reach to represent the impacts of new development constructed in accordance with Minimum Requirement To construct the analysis, the pre-development condition was assumed to be dense forest on C soils - essentially the median soil type for the watershed. Analysis of 51 years of simulated runoff events using the BASINS Synoptic Analysis tool gives a 2-year peak flow of 0.00623 in/hr, so the control requirements apply from 0.000498 to 0.00311 in/hr. The generic BMP (which could, for instance, be bioretention) is represented as having a treated outflow, QTreat and a bypass outflow, QBypass, so the total outflow is QOut = QTreat + QBypass, all in units of in/hr. The treated outflow is simulated as following a first-order recession curve, similar to groundwater discharge. A continuous mass balance of the BMP behavior relative to an input series (QIn) from simulation of one acre of impervious cover (without any extra surface storage) can then be constructed as follows: QTreat = Min {KGW · Vt-1, QMax}, where Vt-1 is the storage volume at the end of the previous time step, QMax is the maximum allowed outflow rate, and KGW = 1 – AGWRC 1/24, where AGWRC is a daily recession parameter, with the same functional interpretation as the recession parameter in HSPF. Bypass flow occurs when the storage volume exceeds the maximum storage capacity of the BMP: QBypass = Max Vt-1 + QIn – VMax}, where QIn is the inflow for the time step and VMax is the maximum storage capacity. Finally, the new volume at time t is updated as Vt = Min {Vt-1 – QTreat +QIn – QBypass – QSeep, VMax}, where QSeep represents net losses that may include seepage to groundwater or evapotranspiration. Iterative application of this model reveals a set of parameters that satisfies the control requirements of Minimum Requirement with AGWRC = 0.985, QMax = 0.0023 in/hr, VMax = 3.6 in, and QSeep = 0.003 in/hr. (VMax would be applied on the basis of acres of impervious area; if the BMP had a depth of 3 ft this would work out to a requirement of 4,356 ft2 of BMP per each acre of imperviousness.) Application ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 9-3 results to the 1960-2010 simulation are shown in Figure 9-2. The green line shows unmitigated conditions for runoff from impervious surfaces, while the red line represents natural conditions flow, obtained from model simulation of undisturbed forest. The blue line shows mitigated flow, with the BMP representing Minimum Requirement #5 in place, and remains below the natural condition curve across the control range of 0.000498 to 0.00311 in/hr. Figure 9-2. BMP Representation of LID Performance Standard for New Development To implement this generic BMP in the HSPF model via a reach FTable, the output must be represented in units of cfs (per acre, as this is on a unit basis). A factor of 1.008333 converts outflow in ac-in/hr to cfs. The resulting FTable is shown in Table 9-1. Output from this FTable is multiplied by the appropriate area of new impervious surfaces (and the conversion from inches to feet) to link this “reach” to each receiving stream segment. Table 9-1. HSPF FTable for Representing LID BMP on a Unit Area Basis FTABLE 100 Future Imperv LID Standard, in/ac rows cols 11 6 DEPTH AREA VOLUME treated bypass loss in ac ac-in cfs/ac-in-hr 00.000 00.0000 00.00000 00.00000 00.00000 0.000000 00.003 00.0972 00.00300 00.00000 00.00000 0.003025 00.010 00.0972 00.01000 00.00000 00.00000 0.003025 00.167 00.0972 00.16650 00.00010 00.00000 0.003025 00.500 00.0972 00.50000 00.00032 00.00000 0.003025 01.000 00.0972 01.00000 00.00063 00.00000 0.003025 02.000 00.0972 02.00000 00.00127 00.00000 0.003025 03.000 00.0972 03.00000 00.00190 00.00000 0.003025 03.600 00.0972 03.50000 00.00222 00.00000 0.003025 04.000 00.0972 04.00000 00.00222 04.02809 0.003025 10.000 00.0972 10.00000 00.00222 10.07809 0.003025 END FTABLE100 0.0000 0.0005 0.0010 0.0015 0.0020 0.0025 0.0030 0% 20% 40% 60% 80% 100% Outflow (in/hr) Fraction of Time Exceeded Mitigated Natural Umitigated ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 9-4 Flow into the BMP that is not bypassed is assumed to achieve a significant degree of sediment retention as the treated water will likely be filtered through the LID planting medium. Specifically, trapping of 100 percent of sand, 90 percent of silt, and 80 percent of clay is assumed. 9.3 SCENARIO RESULTS Buildout conditions result in an increase in impervious area; however, the extent of directly connected impervious area is already high under current conditions. Therefore, the difference between current conditions and natural conditions is more dramatic than the difference between current and buildout conditions. Scenario statistics for flow at a variety of key locations in the watershed are provided in Table 9-2. There are only small differences between scenarios for median and average flows. For the mainstem, the majority of the flow is provided by spring discharges which are assumed to remain unchanged under the three scenarios. In contrast, large differences are seen for the 2-year and 10-year recurrence daily flows. For the 2-year event, flows under current conditions are much greater than estimated for natural conditions both in the tributaries and at the station on Clarks Creek at 66th Street. In contrast, 2-year and 10-year flows in Clarks Creek at 12th Street are predicted to have increased only relative to natural conditions, mostly because a large portion of the upstream drainage area is protected by Clarks Creek Park. Table 9-2. Scenario Results for Flow Parameter Scenario Clarks Creek at 66th St. Meeker Creek Mouth Clarks Creek at 12th St. Diru Creek Mouth Rody Creek Mouth Median Flow (cfs) Current 63.8 1.4 54.5 1.7 1.8 Natural 62.2 1.7 54.2 1.5 1.6 Buildout 63.9 1.3 54.5 1.7 1.8 Average Flow (cfs) Current 66.8 2.4 54.4 2.3 2.3 Natural 63.1 2.1 54.0 1.7 1.8 Buildout 67.3 2.5 54.4 2.3 2.3 2-year Daily Flow (cfs) Current 182.5 27.0 86.5 16.6 14.3 Natural 116.0 11.8 85.7 8.2 6.6 Buildout 195.0 30.3 86.6 18.2 15.2 10-year Daily Flow (cfs) Current 256.0 46.6 88.9 25.5 21.6 Natural 147.8 19.6 87.1 13.4 10.5 Buildout 279.9 54.6 88.9 28.0 23.3 Figure 9-3 displays flow-duration curves for Clarks Creek at 66th Street in two different ways. The top panel plots daily flow for each scenario versus the percent of time that flow is exceeded, which emphasizes the middle range of flows. The bottom panel plots flows versus empirical recurrence ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 9-5 frequency in the 51-year model simulation, which emphasizes the extreme flows. The top panel emphasizes that there is little difference between scenarios for median and small flows, which are largely determined by spring discharges, although the current and buildout scenarios diverge from natural conditions for flows that are exceeded less than 20 percent of the time – i.e., during wet weather runoff events. The bottom panel shows, in contrast, that there are large differences for larger storm flows that occur with a return frequency of two years or more. Figure 9-3. Flow Durations for Clarks Creek at 66th St. under Current, Natural, and Buildout Conditions Scenario results for sediment (Table 9-3) generally follow the results for flow: There is only a small difference between current conditions and predicted conditions at buildout, but both the current and buildout scenarios have much higher TSS concentrations and sediment loads than are predicted for forested natural conditions. Interestingly, the predicted loads are somewhat lower under buildout conditions than under current conditions. This is due to the sediment removal simulated in the BMPs required under the proposed general permit, which includes lands that are predicted to be re-developed to higher density developed land uses. The simulation of sediment deposition at 12th Street on Upper Clarks 0 50 100 150 200 250 300 350 400 0% 20% 40% 60% 80% 100% Daily Flow (cfs) Percent Greater Current Natural Buildout 0 50 100 150 200 250 300 350 400 0 10 20 30 40 50 60 Daily Flow (cfs) Recurrence (yrs) Current Natural Buildout ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 9-6 Creek suggests that there may have been significant deposition at this location even under natural conditions, due primarily to erosion in the steep reaches immediately upstream. If correct, this result suggests that this portion of Clarks Creek had not reached a dynamic equilibrium under natural conditions, but was instead still actively adjusting to conditions following the conclusion of the last glaciation. Table 9-3. Scenario Results for Sediment Parameter Scenario Clarks Creek at 66th St. Meeker Creek Mouth Clarks Creek at 12th St. Diru Creek Mouth Rody Creek Mouth Median TSS (mg/L) Current 2.9 5.9 2.8 2.8 2.8 Natural 1.7 0.5 1.8 1.9 0.7 Buildout 2.9 5.9 2.8 2.8 2.8 Average TSS (mg/L) Current 6.1 14.8 3.3 9.0 11.0 Natural 2.1 2.4 1.9 3.2 1.9 Buildout 5.6 13.4 3.2 8.3 10.4 Average Annual Sediment Load (tons/yr) Current 578.7 107.2 180.8 51.1 56.8 Natural 138.5 9.9 99.5 7.6 5.7 Buildout 545.0 98.7 174.1 50.1 56.4 Sediment Deposition (tons/yr) Current 10.1 0.1 -11.7 2.6 3.1 Natural 0.8 -0.2 -16.2 -2.3 -1.1 Buildout 8.5 0.1 -10.9 3.7 3.9 The model simulates most active channel degradation as occurring in reach 134 (one reach above 13th Street), with an average of 30.0 tons/yr of scour under current conditions. The natural condition simulation shows less scour, but still simulates 26.0 tons/yr. The buildout condition scenario predicts a slight increase, to 31.0 tons/yr. Relative to natural conditions, the model suggests a large increase in average TSS concentrations and annual sediment load. This is accompanied by a large increase in sediment deposition in lower Clarks Creek at the 66th Street monitoring point. As seen above (Figure 9-3), buildout conditions result in a noticeable increase in the magnitude of large, low-frequency storm event flows, but only small changes in the more frequent flows that do the majority of the work on the channel. An effective work analysis was also conducted for buildout conditions and compared to the results for existing conditions for the Clarks Creek mainstem reaches through the ratio of the sum of the effective work indices, Ep, calculated as Wbuildout/Wexisting (see Section 7.8). Results are summarized in Table 9-4. While Ep is greater than one, the largest value is about 1.06, far less than the criterion of 1.5 recommended as a strong indicator of potential channel instability by MacRae (1992). Thus, the anticipated conditions at buildout (with stormwater controls equivalent to Minimum Requirement do not appear likely to induce significant additional channel instability. ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 9-7 Table 9-4. Change in Effective Work Index from Existing to Buildout Conditions Reach W at Buildout (x 10-8) W, Existing (x 10-8) Ep 139 1.97 1.95 1.00882 138 6.89 6.64 1.03713 137 40.72 38.58 1.05560 135 88.34 87.88 1.00523 134 37.71 37.61 1.00275 133 0.25 0.25 1.00099 114 0.65 0.65 1.00208 112 0.48 0.48 1.00241 109 1.10 1.10 1.00217 107 1.48 1.47 1.00435 106 2.46 2.46 1.00132 104 1.37 1.36 1.00613 101 5.21 5.13 1.01503 In sum, the watershed model scenarios suggest that existing development has substantially altered the natural hydrology and sediment dynamics of Clarks Creek, leading to increased peak flows, increased sediment load, degradation of upland stream reaches, and aggradation of reaches in the alluvial plain. However, risks from future development appear relatively small – mostly because most of the available land has already been developed. Mitigation of sediment problems in Clarks Creek would thus require addressing flow and sediment loads from existing development. ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 9-8 (This page left intentionally blank.) ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 10-1 10 References Bicknell, B.R., J.C. Imhoff, J.L. Kittle, Jr., T.H. Jobes, and A.S. Donigian, Jr. 2005. HSPF Version 12.2 User's Manual. National Exposure Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, Athens, GA. Brunner, G.W. 2010. HEC-RAS River Analysis System User’s Manual, Version 4.1. CPD-68. U.S. Army Corps of Engineers Hydrologic Engineering Center, Davis, CA. CH2MHill. 2003. Clear/Clarks Creek Basin Plan Phase 2 Analytical Assumptions and Model Development. Prepared for Pierce County Water Programs by CH2M Hill, Bellevue, WA. Donigian, A.S., Jr. 2000. HSPF Training Workshop Handbook and CD. Lecture #19. Calibration and Verification Issues. EPA Headquarters, Washington Information Center, 10-14 January, 2000. Prepared for U.S. EPA, Office of Water, Office of Science and Technology, Washington, DC. Donigian, A.S., Jr., and J.T. Love. 2003. Sediment Calibration Procedures and Guidelines for Watershed Modeling. Aqua Terra Consultants, Mountain View, CA. Doten, C.O. 2011. Updating State Highway Basin HSPF WDM File. Brown and Caldwell, Seattle, WA. Driscoll, E.D., P.E. Shelley, and E.W. Strecker. 1990. Pollutant Loadings and Impacts from Highway Stormwater Runoff, Volume III: Analytical Investigation and Research Report. FHWA-RD-88-008. Federal Highway Administration, Washington, DC. Haith, D.A., and D.E. Merrill. 1987. Evaluation of a daily rainfall erosivity model. Transactions of the American Society of Agricultural Engineers, 28(6): 1916-1920. Haith, D.A., R. Mandel, and R.S. Wu. 1992. GWLF - Generalized Watershed Loading Functions, Version 2.0 - User’s Manual. Department of Agricultural Engineering, Cornell University, Ithaca, NY. Herrera. 2007. Water Quality Statistical and Pollutant Loadings Analysis, Green-Duwamish Watershed Water Quality Assessment. Prepared for King County Dept. of Natural Resources and Parks by Herrera Environmental Consultants, Inc., Seattle, WA. Johnson, K.H., M.E. Savoca, and B. Clothier. 2011. Numerical Simulation of the Groundwater-flow System in the Chambers-Clover Creek Watershed and Vicinity, Pierce County, Washington. Scientific Investigations Report 2011–5086. U.S. Geological Survey, Reston, VA. Jones, M.A., L.A. Orr, J.C. Ebbert, and S.S. Sumioka. 1999. Ground-Water Hydrology of the Tacoma- Puyallup Area, Pierce County, Washington. Water-Resources Investigations Report 99-4013. U.S. Geological Survey, Tacoma, WA. Leopold, L.B., M.G. Wolman, and J.P. Miller. 1964. Fluvial Processes in Geomorphology. W.H. Freeman, San Francisco. Lumb. A.M., R.B. McCammon, and J.L. Kittle, Jr. 1994. User’s Manual for an Expert System (HSPEXP) for Calibration of the Hydrological Simulation Program – FORTRAN. Water-Resources Investigation Report 94-4168. U.S. Geological Survey, Reston, VA. MacRae, C.R. 1992. The Role of Moderate Flow Events and Bank Structure in the Determination of Channel Response to Urbanization. Pp. 12.1-12.21 in Proceedings of the 45th Annual Conference of the Canadian Water Resources Association. Mastin, M.C. 1996. Surface-Water Hydrology and Runoff Simulations for Three Basins in Pierce County, Washington. Water-Resources Investigations Report 95-4068. U.S. Geological Survey, Tacoma, WA. ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 10-2 Moore, K. 2007. Two Automated Methods for Creating Hydraulic Function Tables (FTABLES). BASINS Technical Note 2. Office of Water, U.S. Environmental Protection Agency, Washington, DC. NHC. 2003. Clear and Canyon Creeks, Puyallup River to Pioneer Way, Community Number 530138. Flood Insurance Mapping Study, Pierce County, WA and Unincorporated Areas. Northwest Hydraulic Components. Novotny, V. and G. Chesters. 1981. Handbook of Nonpoint Pollution. Van Nostrand Reinhold, New York. Novotny, V. and H. Olem. 1994. Water Quality; Prevention, Identification, and Management of Diffuse Pollution. Van Nostrand Reinhold, New York. Pierce County. 2009. Clear/Clarks Creek Basin Plan. Pierce County Public Works and Utilities Water Programs Division, Pierce County, WA. Richardson, C.W., G.R. Foster, and D.A. Wright. 1983. Estimation of erosion index from daily rainfall amount. Transactions of the American Society of Agricultural Engineers, 26(1): 153-157, 160. Roehl, J.W. 1962. Sediment Source Areas, Delivery Ratios and Influencing Morphological Factors. Publ. No. 59. International Association of Hydrological Sciences, pp. 202-213. Rossman, L.A. 2010. Storm Water Management Model, User’s Manual, Version 5.0. EPA/600/R- 05/040. U.S. Environmental Protection Agency, National Risk Management Research Laboratory, Cincinnati, OH. Savoca, M.E., W.B. Welch, K.H. Johnson, and R.C. Lane. 2010. Hydrogeologic Framework, Groundwater Movement, and Water Budget in the Chambers-Clover Creek Watershed and Vicinity, Pierce County, Washington. Scientific Investigations Report 2010-5055. U.S. Geological Survey, Reston, VA. Selker, J.S., D.A. Haith, and J.E. Reynolds. 1990. Calibration and testing of daily rainfall erosivity model. Transactions of the American Society of Agricultural Engineers, 33(5): 1612-1618. Tetra Tech. 2010. Clarks Creek Dissolved Oxygen TMDL and Implementation Plan, Data Review and Analysis. Prepared for USEPA Region 10 by Tetra Tech, Inc., Research Triangle Park, NC. Tetra Tech. 2011. Modeling Quality Assurance Project Plan for Clarks Creek Sediment Study. QAPP 287, Revision 1. Prepared for Puyallup Tribe of Indians by Tetra Tech, Inc., Research Triangle Park, NC USEPA. 2000. BASINS Technical Note 6, Estimating Hydrology and Hydraulic Parameters for HSPF. EPA-823-R00-012. Office of Water, U.S. Environmental Protection Agency, Washington, DC. USEPA. 2006. Sediment Parameter and Calibration Guidance for HSPF. BASINS Technical Note 8. Office of Water, U.S. Environmental Protection Agency, Washington, DC. WA ECY. 2008. Clarks Creek Watershed Fecal Coliform Bacteria Total Maximum Daily Load and Water Quality Improvement Report. Publication No. 07-10-110. Washington State Department of Ecology. Walling, D.E. 1983. The sediment delivery problem. Journal of Hydrology, 65:209-237. Wischmeier, W.H., and D.D. Smith. 1978. Predicting Rainfall Erosion Losses – A Guide to Conservation Planning. Agricultural Handbook 537. U.S. Department of Agriculture, Washington, DC. ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 A-1 Appendix A. Impervious Area Determination ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 A-2 (This page left intentionally blank.) ---PAGE BREAK--- Clarks Creek Watershed Model (REVISED DRAFT) April 4, 2012 A-3 [Insert file ---PAGE BREAK--- Memorandum Date: December 1, 2011 To: Char Naylor/PTI c: Jon Butcher/Tetra Tech Mike Milne/B&C From: Jerry Scheller/Tetra Tech, Tracy Winjum/Tetra Tech Project No./Name: 135-64934-11001-01/Clark Creek Sediment Study Subject: Impervious Surfaces Analysis This memorandum presents the approach used for estimating impervious area in the Clark Creek Basin for input into the HSPF model developed for the Clarks Creek Sediment Reduction Project. Roadways, parking lots sidewalks, roof tops and any other hard or paved surface that prevent rainfall from infiltrating into the ground are considered to be impervious surfaces. Impervious surfaces are classified two ways, directly-connected and indirectly-connected. Directly-connected impervious areas (DCIA) are impervious surfaces that are directly connected to the receiving water through a constructed drainage system. Usually these drainage conveyance systems are comprised of curb and gutter, pipes, and ditches and speed the flow of stormwater runoff to the receiving water. For this reason, DCIA has the greatest impact on peak flow and runoff volumes in the Clarks Creek basin. Indirectly-connected impervious surfaces are those surfaces located adjacent to vegetated areas such as lawn, forest or pasture, and usually exhibit runoff characteristics similar to the adjacent land cover. Total impervious area (TIA) is the combination of the directly- and indirectly-connected impervious area. For this memo, impervious surfaces will be presented as DCIA and TIA. Impervious surface is represented in the HSPF model with a series of Hydrologic Response Units (HRUs), referred to as that define runoff characteristics during rainfall events. Four HSPF classifications were identified in the memorandum HRU’s for Clarks Creek Model (Tetra Tech, 2011). The four classifications are described below: 1: Impervious area of major highways. 2: Impervious areas of roads and driveways in residential, park and institutional areas. 3: Impervious area of high-density development parking lots. 4: Building footprints. Pervious HRU and HSPF model development is described in a separate memorandum. 1 impervious area for major highways was measured directly for the aerial photography. SR512 is the only major highway in the Clarks Creek Basin. Directly measured impervious highway area is documented in Table A-1 in Attachment A. The impervious area for 2, 3, and 4 classifications were computed by applying a representative fraction of TIA and DCIA for roads and driveways for a variety of land covers in the Clarks Creek basin. Impervious fractions were estimated by direct measurement from aerial photos by sampling of nine locations assumed to represent a range of land covers found in the basin. Sampled represented areas are documented in Attachment B. ---PAGE BREAK--- Memorandum 2 The impervious fractions were applied to the landuse on a parcel basis taken from the Land Use shapefile provided by Piece County. Rights-of-way were classified as commercial, residential or rural based on adjoining parcel land use. Impervious fractions were applied to each right-of-way area. Figure 1 shows the land and right-of-way use in the Clarks Creek basin. Table 1 shows the corresponding impervious area fraction for each land use. Figure 2 Land Use in the Clarks Creek Basin (Pierce County, 2011) ---PAGE BREAK--- Memorandum 3 TABLE 1 PARCEL LAND USE ESTIMATED IMPERVIOUS AREA FRACTION DCIA Fraction Land Use Category TIA Road- Parking HDa Parking Roof Source Unknown 0 0 0 SFR (0-1/8 acre) 56 11 40 Sampledb SFR (1/8-1/4 acre) 41 9 0 Sampledb SFR (1/8-1/4 acre) - Recentc 41 9 20 Sampledb SFR (1/4-1/2 acre) 39 10 0 Sampledb SFR (1/4-1/2 acre) - Recentc 39 10 21 Sampledb SFR (1/2-1 acre) 17 5 0 Sampledb SFR acre) 17 5 0 Sampledb MFR 75 0 48 25 Sampledb MFR - Low-Density 40 10 5 By Inspectiond Group Quarters/Other 75 0 48 25 Assumed to be MFR Mobile Homes 85 0 60 25 By inspectiond Residential Outbuildings 17 5 0 Assumed to be SFR (1/2 - 1 ac) Commercial/Service 85 0 70 14 Sampledb Industrial 90 0 45 45 By Inspection Transportation, Communication, Utilities 90 90 0 Education 53 0 24 26 Sampledb Public Facilities 90 0 45 45 Quasi-Public Facilities 90 0 45 45 By Inspection Open Space/Recreation 5 5 0 Open Space/Recreation - High-Density 86 0 70 14 By Inspectiond Resource Land 0 0 0 Vacant 0 0 0 DCIA = Directly Connected Impervious Area, TIA = Total Impervious Area, HD = High Density, SFR = Single Family Residential, MFR=Multi-Family Residential a. High density parking associated with multi-car parking areas in commercial, MFR, etc. b. Sampled areas documented in Attachment B. c. Recent developments are assumed to have rooftops directly connected to storm drain system. See Figure 1 for Recent developments. d. From aerial photography. See Table A-2 for list of parcels in this category. ---PAGE BREAK--- Memorandum 4 The following assumptions were used to develop DCIA and TIA estimates: Single-family residential less than 1/8 acre assumed to have roof downspouts connected to storm drain. "Recent" single-family development between 1/8 and 1/2 acre assumed to have roof downspouts connected to storm drain. "Recent" developments identified by inspection of the aerial photos based on street and house patterns and are documented in Figure 1. Low density multi-family residential parcels identified by inspection of the aerial photo, DCIA values assumed. Parcels are listed Table A-2 in Attachment A. Mobile home parks identified by inspection of the aerial photos. DCIA assigned based on sampled multi-family residential values. Parcels are listed in Table A-3 in Attachment A. Non-park mobile homes assigned single-family residential DCIA values for older developments. High-density open space identified by inspection of the aerial photo. DCIA assigned based on sampled commercial values. Parcels are listed in Table A-2 in Attachment A. By inspection of the aerial photo, "Unknown" land use appears to cover open tracts of green space or native growth protection area. Three high-density properties identified and assigned commercial DCIA values Group Quarters/Other assigned multi-family residential DCIA values. Industrial, Transportation, Communication, Utilities, Public Facilities and Quasi-Public Facilities assigned DCIA values estimated by inspection of the aerial photo. Estiamted DCIA and TIA for each HSPF Subbasin are shown in Figure 3 and Table 3. Figure 3. DCIA and TIA for Clarks Creek HSPF Subbasins 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 201 202 203 301 Total Impervious Area HSPF Subbasin Total Impervious Area Effective Impervious Area ---PAGE BREAK--- Memorandum 5 TABLE 3 HSPF AREA DCIA (acres) HSPF Subbasin Area (acres) TIA (acres) TIA Road/Parking Roof HD Parking Major Highway Total DCIA %DCIA 101 33.2 11.9 36% 3.7 1.7 5.1 0.0 10.6 32% 102 109.9 28.7 26% 3.5 5.6 8.4 5.6 23.0 21% 103 123.2 20.4 17% 8.1 0.8 1.4 0.8 11.1 9% 104 31.2 5.9 19% 3.1 0.0 0.0 0.0 3.1 10% 105 85.8 40.3 47% 24.0 0.4 0.8 0.4 25.7 30% 106 13.9 1.0 8% 1.0 0.0 0.0 0.0 1.0 8% 107 17.4 3.1 18% 0.6 0.3 0.7 0.3 2.0 11% 108 81.7 17.9 22% 11.0 0.7 1.3 0.7 13.5 17% 109 28.3 15.0 53% 1.6 3.7 3.4 3.7 12.4 44% 110 82.9 39.7 48% 20.7 0.6 1.1 0.6 23.1 28% 111 80.1 40.8 51% 17.0 3.0 3.8 3.0 26.9 34% 112 28.5 5.8 20% 2.5 0.1 0.2 0.1 2.9 10% 113 100.8 51.9 52% 24.5 2.3 3.1 2.3 32.2 32% 114 73.9 24.7 33% 9.3 2.5 3.6 2.5 18.0 24% 115 101.5 50.2 49% 19.1 5.0 5.1 5.0 34.3 34% 116 21.8 12.3 57% 4.5 1.8 2.1 1.8 10.2 47% 117 81.7 61.1 75% 21.7 8.1 17.5 8.1 55.4 68% 118 17.8 15.1 88% 13.6 0.4 1.3 0.4 15.7 88% 119 24.7 15.0 61% 5.8 1.6 3.1 1.9 12.3 50% 120 3.0 1.9 61% 0.0 0.3 1.4 0.1 1.8 61% 121 4.5 4.0 90% 0.5 0.5 2.5 0.5 4.0 89% 122 62.7 22.2 35% 9.1 0.7 3.6 0.7 14.1 23% 123 170.1 117.4 69% 18.7 14.9 75.2 1.9 110.6 65% 124 47.3 29.5 62% 12.3 5.1 7.5 0.6 25.5 54% 125 21.5 18.2 84% 15.0 0.6 2.0 0.6 18.1 84% 126 24.1 21.3 92% 5.1 3.6 9.9 3.6 22.2 92% 127 115.3 56.2 49% 24.5 6.1 8.2 6.1 44.9 39% 128 93.8 26.9 29% 10.4 4.0 0.0 4.0 18.4 20% 129 145.2 53.1 37% 29.4 5.6 4.6 2.2 41.8 29% 130 18.6 12.0 65% 1.6 1.4 7.2 1.4 11.6 62% 131 114.2 83.3 73% 13.8 11.5 55.2 1.2 81.7 72% 132 131.9 40.6 31% 20.9 3.7 0.0 3.7 28.3 21% 133 48.3 9.1 19% 5.0 0.0 0.0 0.0 5.0 10% ---PAGE BREAK--- Memorandum 6 TABLE 3 (CONTINUED) HSPF AREA DCIA (acres) HSPF Subbasin Area (acres) TIA (acres) TIA Road/Parking Roof HD Parking Major Highway Total DCIA %DCIA 134 100.2 21.6 22% 17.2 0.3 0.0 0.3 17.9 18% 135 139.7 20.8 15% 17.2 0.0 0.0 0.0 17.2 12% 136 91.3 27.9 31% 13.0 2.5 0.7 2.5 18.8 21% 137 49.0 8.7 18% 3.3 0.5 0.5 0.5 4.9 10% 138 138.4 39.9 29% 21.5 2.9 1.0 2.0 27.4 20% 139 167.3 69.4 41% 25.7 10.2 15.7 2.2 53.9 32% 140 80.0 62.3 78% 1.5 20.0 18.4 20.0 59.9 75% 141 46.1 28.8 62% 10.3 6.0 3.3 6.0 25.5 55% 142 34.3 10.3 30% 3.6 1.4 1.3 1.4 7.7 23% 143 103.2 42.9 42% 11.9 7.3 6.7 7.3 33.2 32% 144 80.4 30.8 38% 10.2 5.2 2.7 5.2 23.3 29% 145 46.6 18.9 41% 10.3 0.3 0.6 0.3 11.5 25% 146 78.3 33.3 42% 7.6 6.4 5.9 6.4 26.4 34% 147 123.0 28.9 24% 11.5 1.9 1.0 1.9 16.4 13% 148 61.5 23.2 38% 13.0 0.1 0.1 0.1 13.3 22% 149 125.3 42.7 34% 23.2 1.0 1.9 0.8 26.9 21% 150 128.4 54.8 43% 19.3 7.2 15.7 3.9 46.0 36% 151 161.5 46.4 29% 23.5 1.4 2.5 1.4 28.9 18% 152 106.5 27.6 26% 14.3 0.4 0.4 0.4 15.5 15% 153 68.3 28.6 42% 11.4 4.7 3.7 4.7 24.6 36% 154 93.3 26.8 29% 14.3 0.1 0.2 0.1 14.7 16% 155 56.1 4.5 8% 2.7 0.0 0.0 0.0 2.7 5% 156 94.8 30.3 32% 18.3 0.1 0.1 0.1 18.6 20% 157 163.4 43.1 26% 26.6 0.0 0.0 0.0 26.6 16% 158 155.8 60.9 39% 29.9 1.8 3.4 1.8 36.9 24% 159 104.4 44.8 43% 18.6 3.6 7.0 3.6 32.8 31% 160 106.5 40.1 38% 18.2 2.4 6.2 0.5 27.3 26% 161 184.7 51.9 28% 25.2 5.7 5.4 1.4 37.7 20% 162 68.8 11.7 17% 9.0 0.0 0.0 0.0 9.0 13% 163 80.5 3.2 4% 2.3 0.0 0.0 0.0 2.3 3% 164 69.1 11.8 17% 6.0 0.0 0.0 0.0 6.0 9% 165 31.4 0.5 1% 0.4 0.0 0.0 0.0 0.4 1% 166 97.7 27.0 28% 11.6 1.6 3.1 1.6 18.0 18% ---PAGE BREAK--- Memorandum 7 TABLE 3 (CONTINUED) HSPF AREA DCIA (acres) HSPF Subbasin Area (acres) TIA (acres) TIA Road/Parking Roof HD Parking Major Highway Total DCIA %DCIA 167 107.5 62.4 58% 16.5 8.8 17.0 8.8 51.1 48% 168 120.8 36.4 30% 18.5 0.3 0.6 1.5 21.0 17% 169 142.2 68.4 48% 22.7 14.5 19.5 0.9 57.7 41% 170 92.6 25.9 28% 11.7 3.3 0.4 3.3 18.7 20% 201 121.1 75.4 62% 29.1 10.2 10.0 10.2 59.4 49% 202 115.1 89.3 78% 35.4 11.6 21.7 11.6 80.3 70% 203 117.6 99.8 85% 36.5 13.9 28.8 13.9 93.1 79% 301 525.6 236.9 45% 55.8 29.9 93.2 25.5 204.3 39% Total 6,717 2,675 40% 1,041 284 538 216 2,080 31% ---PAGE BREAK--- Memorandum 8 ---PAGE BREAK--- Memorandum 9 ATTACHMENT A TABLE A-1 DIRECTLY MEASURED SUBBASIN IMPERVIOUS AREA Subbasin Impervious Area (ac) 119 1.9 120 0.1 123 1.9 124 0.6 125 0.6 129 2.2 131 1.2 138 2.0 139 2.2 149 0.8 150 3.9 160 0.5 161 1.4 168 1.5 169 0.9 301 25.5 ---PAGE BREAK--- Memorandum 10 ATTACHMENT A (CONTINUED) TABLE A-2 PARCELS WITH EXCEPTIONS TO LAND USE CLASSIFICATIONS Mobile Home Parcels Assumed to be High Density Properties Multi-Family Parcels assumed to be Low-Density Properties Open-Space Parcels Assumed to be High Density Properties [PHONE REDACTED] [PHONE REDACTED] [PHONE REDACTED] [PHONE REDACTED] [PHONE REDACTED] [PHONE REDACTED] [PHONE REDACTED] [PHONE REDACTED] [PHONE REDACTED] [PHONE REDACTED] [PHONE REDACTED] [PHONE REDACTED] [PHONE REDACTED] [PHONE REDACTED] [PHONE REDACTED] [PHONE REDACTED] [PHONE REDACTED] [PHONE REDACTED] [PHONE REDACTED] [PHONE REDACTED] [PHONE REDACTED] [PHONE REDACTED] [PHONE REDACTED] [PHONE REDACTED] [PHONE REDACTED] [PHONE REDACTED] [PHONE REDACTED] [PHONE REDACTED] [PHONE REDACTED] [PHONE REDACTED] [PHONE REDACTED] [PHONE REDACTED] [PHONE REDACTED] [PHONE REDACTED] [PHONE REDACTED] [PHONE REDACTED] [PHONE REDACTED] [PHONE REDACTED] [PHONE REDACTED] [PHONE REDACTED] [PHONE REDACTED] [PHONE REDACTED] [PHONE REDACTED] [PHONE REDACTED] [PHONE REDACTED] [PHONE REDACTED] [PHONE REDACTED] [PHONE REDACTED] [PHONE REDACTED] [PHONE REDACTED] [PHONE REDACTED] [PHONE REDACTED] [PHONE REDACTED] [PHONE REDACTED] [PHONE REDACTED] [PHONE REDACTED] [PHONE REDACTED] [PHONE REDACTED] [PHONE REDACTED] ---PAGE BREAK--- Memorandum 11 ATTACHMENT B Figure B-1 Sampled Representative Impervious Areas ---PAGE BREAK--- Memorandum 12 ATTACHMENT B (CONTINUED) TABLE B-1 IMPERVIOUS AREA FROM REPRESENTATIVE LAND USE SAMPLING Land Use TIA DCIA Roof Imp. Driveway/ Parking Imp. High Density/Multi-family Residential 75% 73% 25% 48% Medium Density Residential/Single Family < 1/8 acre 56% 52% 40% 11% 1/8 acre to 1/4 acre (Roof Disconnected) 41% 9% 9% Sample 1 39% 7% 7% Sample 2 37% 10% 10% Sample 3 45% 10% 10% 1/8 acre to 1/4 acre (Roof connected) 41% 30% 20% 9% Sample 1 39% 30% 23% 7% Sample 2 37% 28% 17% 10% Sample 3 45% 31% 21% 10% 1/4 acre to 1/2 acre (Roof Disconnected) 39% 31% 21% 10% 1/4 acre to 1/2 acre (Connected) 39% 10% 0% 10% 1/2 acre to 1 acre 17% 5% 0% 5% Low Density Residential > 1 acre 17% 5% 0% 5% Commercial 85% 85% 14% 70% Education 53% 50% 26% 24% Rural Road 70% 70% 70% Sample 1 66% 66% 66% Sample 2 74% 74% 74% Residential Road 78% 78% 78% Sample 1 73% 73% 73% Sample 2 83% 83% 83% Commercial Road 100% 100% 100% ---PAGE BREAK--- 7TH ST SE 9TH AV SE SR512 HWY E SR512 HWY W RAMP SR512 RPN1 W 8TH ST SE 0 50 100 Feet Ü High Density Residential (HDR) Legend Representative Area Impervious Indirect Road Roof ---PAGE BREAK--- 28TH AV SE 5TH ST SE 6TH ST SE 27TH AV SE 7TH ST SE 29TH AV SE 28TH AV SE 29TH AV SE 0 50 100 Feet Ü Medium Density Residential (MDR) Lot Size < 1/8 Acre Legend Representative Areas Impervious Indirect Road Roof ---PAGE BREAK--- 7TH AV SW 6TH AV SW 13TH ST SW 14TH ST SW 0 50 100 Feet Ü Medium Density Residential (MDR) 1/8 Acre < Lot Size < 1/4 Acre Legend Representative Areas Impervious Indirect Road Roof ---PAGE BREAK--- W MAIN 3RD AV NW 18TH ST NW 17TH ST NW TACOMA RD 17TH ST SW 0 50 100 Feet Ü Medium Density Residential (MDR) 1/8 Acre < Lot Size < 1/4 Acre Legend Representative Areas Impervious Indirect Road Roof ---PAGE BREAK--- 4TH AV SW 5TH AV SW 9TH ST SW 10TH ST SW 0 50 100 Feet Ü Medium Density Residential (MDR) 1/8 Acre < Lot Size < 1/4 Acre Legend Representative Areas Impervious Indirect Road Roof ---PAGE BREAK--- # 116TH ST E 4TH STPL SW 43RD AV SW 43RD AV 43RD AV SW 0 50 100 Feet Ü Medium Density Residential (MDR) 1/4 Acre < Lot Size <1 Acre Legend Representative Area Impervious Indirect Road Roof ---PAGE BREAK--- ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! 23RD AV SW 0 50 100 Feet Ü Low Density Residential (LDR) Lot Size > 1 Acre Legend Representative Areas Impervious Indirect Road Roof ---PAGE BREAK--- 9TH ST SW 0 50 100 Feet Ü High Density Commercial Legend Representative Areas Impervious Indirect Road Roof ---PAGE BREAK--- 5TH AV SW W PIONEER 11TH ST SW 12TH ST SW 4TH AV SW 0 50 100 Feet Ü Education Legend Representative Areas Impervious Indirect Road Roof ---PAGE BREAK--- S MERIDIAN 37TH AV SE 0 50 100 Feet Ü Commercial Road Legend Representative Area Impervious Indirect Road Roof ---PAGE BREAK--- 14TH ST SW 13TH ST SW 9TH AV SW 0 50 100 Feet Ü Residential Road Legend Representative Area Impervious Indirect Road Roof ---PAGE BREAK--- 4TH AV NW 19TH ST NW 20TH ST NW TACOMA RD 0 50 100 Feet Ü Residential Road Legend Representative Areas Impervious Indirect Road Roof ---PAGE BREAK--- ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! 31ST AV SW 0 50 100 Feet Ü Rural Road Legend Representative Areas Impervious Indirect Road Roof ---PAGE BREAK--- 31ST AV SW 0 50 100 Feet Ü Rural Road Legend Representative Areas Impervious Indirect Road Roof ---PAGE BREAK--- ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan DRAFT for review purposes only. Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan DRAFT (v15).docx Appendix E: Geomorphically Significant Flow Analysis ---PAGE BREAK--- This page intentionally left blank. ---PAGE BREAK--- Technical Memorandum Limitations: This is a draft memorandum and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final report. This document was prepared solely for Puyallup Tribe of Indians in accordance with professional standards at the time the services were performed and in accordance with the contract between Puyallup Tribe of Indians and Brown and Caldwell dated March 31, 2011. This document is governed by the specific scope of work authorized by Puyallup Tribe of Indians; it is not intended to be relied upon by any other party except for regulatory authorities contemplated by the scope of work. We have relied on information or instructions provided by Puyallup Tribe of Indians and other parties and, unless otherwise expressly indicated, have made no independent investigation as to the validity, completeness, or accuracy of such information. 701 Pike Street, Suite 1200 Seattle, Washington 98101 Tel: [PHONE REDACTED] Fax: [PHONE REDACTED] Prepared for: Puyallup Tribe of Indians Project Title: Clarks Creek Sediment Reduction Action Plan Project No.: 140982-006 Technical Memorandum Subject: Geomorphic Magnitude-Frequency Analysis for Clarks Creek and Tributaries Date: November 21, 2012 To: Char Naylor, Water Quality Manager, Puyallup Tribe of Indians From: Mike Milne, Managing Scientist, Brown and Caldwell Copy to: Prepared by: Nathan Foged, Principal Engineer State of Washington Professional Engineer License No. 45533 Reviewed by: Erin Nelson, Managing Engineer State of Washington Professional Engineer License No. 32201 DRAFT ---PAGE BREAK--- ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Geomorphic Magnitude-Frequency Analysis ii DRAFT for review purposes only. Use of contents on this sheet is subject to the limitations specified at the beginning of this document. CCSRAP E (GeomorphicMFA_TechMemo_20121121(v5))_track changes accepted.docx Table of Contents List of Figures iii List of Tables iii 1. Introduction 1 2. Background 1 2.1 Dynamic Equilibrium 1 2.2 Hydromodification and Channel Instability 2 2.3 Geomorphically Significant Flows 3 3. MFA Methodology 5 3.1 Effective Work Curves 5 3.1.1 Flow Duration Density 5 3.1.2 Stream Channel Hydraulics 7 3.1.3 Sediment Gradation 8 3.1.4 Effective Work Index 9 3.2 Geomorphically Significant Flows Evaluation 3.2.1 Calculation of the Lower and Upper Bounds 3.2.2 Regulatory Thresholds 4. Results and Discussion References Attachment A: Maps 1 Attachment B: Reach Summaries 1 Attachment C: Tabulated Results 1 ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Geomorphic Magnitude-Frequency Analysis iii DRAFT for review purposes only. Use of contents on this sheet is subject to the limitations specified at the beginning of this document. CCSRAP E (GeomorphicMFA_TechMemo_20121121(v5))_track changes accepted.docx List of Figures Figure 1. Conceptual illustration of channel incision caused by urban discharges 2 Figure 2. Relation between applied stress and frequency of occurrence in geomorphic processes 3 Figure 3. MFA used to define the effective discharge and geomorphically significant flows for a stream section 4 Figure 4. Example HSPF output hydrograph for Upper Clarks Creek 5 Figure 5. Example flow duration curve for Upper Clarks Creek 6 Figure 6. Example flow duration density/distribution data for Upper Clarks Creek 6 Figure 7. Selection of bed sediment classes 8 Figure 8. Composite gradation curves for bed sediment classes 8 Figure 9. Example MFA results plot for lower Clarks Creek (Reach CC-R01) Figure 10. Example MFA results plot for upper Clarks Creek (Reach CC-R21) List of Tables Table 1. Sediment Characteristics for Composite Sediment Classes 9 Table C-1. Geomorphically Significant Flow Ranges for Clarks Creek C Table C-2. Geomorphically Significant Flow Ranges for Diru Creek C Table C-3. Geomorphically Significant Flow Ranges for Meeker Creek C Table C-4. Geomorphically Significant Flow Ranges for Rody Creek C Table C-5. Geomorphically Significant Flow Ranges for Silver Creek C Table C-6. Geomorphically Significant Flow Ranges for Woodland Creek C ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Geomorphic Magnitude-Frequency Analysis 1 DRAFT for review purposes only. Use of contents on this sheet is subject to the limitations specified at the beginning of this document. CCSRAP E (GeomorphicMFA_TechMemo_20121121(v5))_track changes accepted.docx 1. Introduction Brown and Caldwell (BC) is currently working with the Puyallup Tribe of Indians (Tribe) on the Clarks Creek Sediment Reduction Action Plan (Action Plan). The purpose of the Action Plan is to identify sediment sources within the Clarks Creek watershed (see Map 1, Attachment A) and develop recommendations for reducing sediment loads to lower Clarks Creek. As part of this project, BC has performed detailed analyses to evaluate stream stability and mitigation measures for reducing sediment loadings that originate from degrading stream reaches. BC’s approach is based on the concept of “effective work” as described by Wolman and Miller (1960), where geomorphic processes are driven by the magnitude and frequency of the influencing forces. More specifically, fluvial morphology is strongly influenced by both the magnitude and frequency of stream flows. Thus, applying a magnitude-frequency-based methodology allows BC to examine the long-term channel-forming effects of a full range of stream flows. This type of analysis is commonly used to identify the “geomorphically significant flows” for a stream. Objective: The purpose of this technical memorandum is to describe the results of the geomorphic magni- tude-frequency analysis performed by BC and provide the calculated ranges of geomorphically significant flows for Clarks, Rody, Diru, Woodland, Silver, and Meeker creeks. 2. Background The following subsections provide some background and context related to the effects of urbanization on stream geomorphology. Subsections 2.1 through 2.3 discuss fundamental concepts relating to stream channel formation and perturbations caused by watershed urbanization. Subsection 2.4 provides a brief discussion of the regulatory context with respect to stormwater management in Washington State. 2.1 Dynamic Equilibrium Alluvial channels form and continually shift in response to temporal sequences of flow rate and sediment supply. Over periods of many years, channels adjust to flow and sediment regimes through changes in geometry planform, cross-sectional dimensions, and longitudinal slope). Given a period with a relatively constant flow regime and sediment supply, a channel approaches a stable geometry and is considered to be in “dynamic equilibrium.” This is not to say the channel would be static, but rather that morphological responses to extreme events would only be temporary and that a more stable morphology would continually be restored over time by the long-term formative conditions of the system. This geomorphic concept of disturbance, channel adjustment, and dynamic equilibrium is qualitatively represented by Lane’s Principle (1955): 𝑄𝑠𝐷50 ∝𝑄𝑤𝑆 where Qs is sediment load, D50 is the 50th percentile of the sediment grain size distribution, Qw is the stream discharge, and S is the channel slope The relationship represented by Lane’s Principle suggests that a long-term shift in any of these factors would destabilize the system and initiate a compensatory response in one or more of the other factors as the system attempts to restore equilibrium. For example, Lane’s Principle suggests that if stream discharges were to increase while sediment supply and grain size distribution remain constant, then the channel slope would need to decrease to restore equilibrium. ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Geomorphic Magnitude-Frequency Analysis 2 DRAFT for review purposes only. Use of contents on this sheet is subject to the limitations specified at the beginning of this document. CCSRAP E (GeomorphicMFA_TechMemo_20121121(v5))_track changes accepted.docx 2.2 Hydromodification and Channel Instability Urbanization within a watershed typically replaces natural vegetated landscapes with impervious surfaces such as roads, parking lots, and buildings. These changes reduce the capacity of the land surface to intercept and infiltrate precipitation. Furthermore, traditional stormwater infrastructure tends to route runoff from impervious surfaces through gutters and pipes, which increases the rate of conveyance to streams. Consequently, the magnitude, frequency, and duration of runoff reaching stream channels increases, thereby increasing the total discharges to streams and shifting the hydrologic flow regime. This phenomenon is referred to as “hydromodification.” Booth (1990) described how increased runoff associated with impervious surfaces in urbanized watersheds has contributed to channel instability and incision in Pacific Northwest streams. Bledsoe and Watson (2001) further described the effects of urbanization on streams by investigating explicit links between increased imperviousness and increased risk of channel instability. The basic mechanism through which urban discharges destabilize streams can be conceptualized by applying Lane’s Principle to a hypothetical stream reach. As flow rates within the stream reach increases, the sediment transport capacity also increases; however, the sediment supply coming into the stream reach stays the same, as does the size of the bed material (in the near term). Additional sediment is recruited from the stream bed and banks and conveyed thereby causing the channel to degrade vertically (incision) and laterally (channel widening). The process continues to reduce the slope of the stream channel until a new equilibrium slope is reached. Channel incision often results in the formation of headcuts, or abrupt steps in channel gradient that propagate upstream (see Figure Figure 1. Conceptual illustration of channel incision caused by urban discharges Image obtained from Santa Clara Valley Urban Runoff Pollution Prevention Program (SCVURPPP, 2005). ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Geomorphic Magnitude-Frequency Analysis 3 DRAFT for review purposes only. Use of contents on this sheet is subject to the limitations specified at the beginning of this document. CCSRAP E (GeomorphicMFA_TechMemo_20121121(v5))_track changes accepted.docx 2.3 Geomorphically Significant Flows Although observations from catastrophic events often suggest that infrequent events of immense magnitude tend to drive geomorphic processes such as stream channel formation, this is typically not the case. Wolman and Miller (1960) described how the geomorphic evolution of landscapes is strongly influenced by the amount “work” done by the forces acting on the system shear forces caused by flowing water), and that the relative amount of work done depends not only on the magnitude of the force, but also the frequency of occurrence. Effective Work. Figure 2 is a graphical representation of the “work done” concept, where the frequency of occurrence is log-normally distributed and the magnitude of the influencing force applied stress) increases in accordance with a power function. The product of the frequency of the occurrences and the magnitude of the influencing force is referred to as the “effective work” curve (noted in Figure The relationship shown in Figure 2 illustrates how frequent mid-range events do more effective work than extremely large relatively rare events. The effective work relationship can be applied to fluvial processes because hydrologic events tend to be log-normally distributed, and the movement of sediment by water can be represented by a power function relating sediment transport to effective shear stress as follows: 𝑞= 𝑘(𝜏−𝜏𝑐)𝑛 where q is the rate of sediment transport, k is a constant related to the characteristics of the transported material, τ is the shear stress per unit area, τc is the critical or threshold shear stress required to move the material, and n is an exponent (Leopold et al. 1964) The critical shear stress parameter is particularly important in the above equation; the effective work curve applies only to flow rates in excess of a minimum threshold for sediment movement. In other words, if shear stresses exerted by flows are not sufficient to initiate movement of bed sediments do not achieve incipient motion), then effective work is essentially zero. Magnitude Frequency Analysis. Application of the effective work concept is often referred to as magnitude- frequency analysis (MFA). Bledsoe et al. (2007) describes MFA as a fundamental tool for fluvial stream assessment. MFA can be used to define the “effective discharge” for a stream, which is the flow rate corresponding to the maximum work on the effectiveness curve (Bledsoe et al., 2007). The effective discharge is roughly equivalent to the channel-forming (or bankfull) discharge as defined by Leopold et al. (1964). MFA can also be used to define geomorphically significant flows, or the range of flow rates over which a substantial portion of the channel-forming work is done. Leopold et al. (1964) describes geomorphically significant flows as the range of flow rates occurring between a lower limit of competence (critical stress necessary for grain movement) and an upper limit at which flow is no longer confined to the channel greater than bankfull discharge). Figure 2. Relation between applied stress and frequency of occurrence in geomorphic processes Image obtained from Wolman and Miller (1960). ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Geomorphic Magnitude-Frequency Analysis 4 DRAFT for review purposes only. Use of contents on this sheet is subject to the limitations specified at the beginning of this document. CCSRAP E (GeomorphicMFA_TechMemo_20121121(v5))_track changes accepted.docx Figure 3 shows a modified version of the effective work concept where MFA is used to define the effective discharge and range of geomorphically significant flows for a stream. Figure 3. MFA used to define the effective discharge and geomorphically significant flows for a stream section Image obtained from Santa Clara Valley Urban Runoff Pollution Prevention Program (SCVURPPP, 2005). Discharge frequency distribution for the stream (curve in Figure 3) is created using a series of discrete discharge1 bins. The value at each point in the discharge frequency curve would represent the amount of time stream discharges fall within the specified bin range, typically expressed in terms of hours per year. The size of the bins can be variable as long as the distribution of discharges is adequately represented. The sediment discharge curve (curve in Figure 3) can be calculated by either a sediment transport function or an equivalent work rate function. In either case, the curve represents the rate at which sediment is mobilized for any given stream discharge (higher discharge rates result in greater mobilization for the particle sizes evaluated). Multiplying stream discharge rates by sediment transport rates (or effective work rates) provides results in terms of total sediment load or total effective work (units of mass mobilized or units of work per year). This is represented by curve on Figure 3 (in this case, shown as sediment load). 1 The terms “flow,” “flow rate,” and “discharge” are used interchangeably throughout this document. In general, the term “discharge” is used for an estimated or calculated quantity representing the volumetric rate of flow within a stream channel. ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Geomorphic Magnitude-Frequency Analysis 5 DRAFT for review purposes only. Use of contents on this sheet is subject to the limitations specified at the beginning of this document. CCSRAP E (GeomorphicMFA_TechMemo_20121121(v5))_track changes accepted.docx 3. MFA Methodology BC developed an MFA Spreadsheet Tool to evaluate effective work on stream channels within the Clarks Creek basin. The MFA Spreadsheet Tool brings together inputs from several data sources to calculate effective work curves. Subsection 3.1 describes the development of specific data inputs. The calculated effective work curves were used to calculate geomorphically significant flow bounds assuming a specified level of control (see Subsection 3.2.1). The upper and lower flow bounds were then compared with permitted regulatory thresholds (see Subsection 3.2.2). Results from the MFA are summarized in Section 4. 3.1 Effective Work Curves The MFA Spreadsheet Tool requires three primary sources of input data: flow duration density curves (hydrology), stream channel rating curves (hydraulics), and sediment gradation curves (sediment). The following subsections describe each of these in more detail. 3.1.1 Flow Duration Density MFA requires detailed flow frequency data in the form of a discretized flow frequency distribution, which can be developed from long-term stream flow hydrographs. Tetra Tech (April 2012) developed a continuous simulation hydrologic model of the Clarks Creek basin using the U.S. Environmental Protection Agency (EPA)’s Hydrological Simulation Program—Fortran (HSPF). The HSPF model computes hourly stream flow rates based on 51 years of historical rainfall and evapotranspiration data. Figure 4 shows an example of an output hydrograph developed from HSPF results; note that the graph displays only a small portion (4 years) of the full 51-year hydrograph. Flow hydrographs were output at 25 locations throughout the Clarks Creek basin (see Map 2, Attachment Figure 4. Example HSPF output hydrograph for Upper Clarks Creek Note: graph displays only 4 years of data; full simulations produce 51 years of data spanning from 1960 through 2010. 0 2 4 6 8 10 12 14 16 18 20 2007 2008 2009 2010 Hourly Stream Discharge (cfs) Time ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Geomorphic Magnitude-Frequency Analysis 6 DRAFT for review purposes only. Use of contents on this sheet is subject to the limitations specified at the beginning of this document. CCSRAP E (GeomorphicMFA_TechMemo_20121121(v5))_track changes accepted.docx Flow hydrographs were processed into flow duration curves to visually examine the overall distribution of the flow data (see Figure Two hundred discrete flow bins were created for each flow location to cover the range of flows exhibited by the flow duration curves. Flow bin divisions were based on logarithmic intervals rather than arithmetic evenly spaced) intervals. Logarithmic intervals allow for more detail in the lower flow range where a majority of the flows occur. Raff et al. (2007) describe the equations used to obtain the upper and lower bounds of the logarithmic intervals as follows: 𝑈𝑝𝑝𝑒𝑟𝑖= 𝑒(𝐿𝑜𝑔(𝑄𝑚𝑖𝑛)+(𝐵−1)𝐿𝐼) 𝐿𝑜𝑤𝑒𝑟𝑖= 𝑒(𝐿𝑜𝑔(𝑄𝑚𝑖𝑛)+(𝐵−2)𝐿𝐼) where Qmin is the minimum discharge, B is the bin number B ∊ 1, NB, where NB is the total number of bins; in this case NB = 200), and LI is the logarithmic interval between the minimum and maximum flows defined as: 𝐿𝐼= ln(𝑄𝑚𝑎𝑥) −ln (𝑄𝑚𝑖𝑛) 𝑁𝐵−1 Hourly values from the stream flow hydrographs were totaled based on the upper and lower bounds for each flow bin. The total hourly values falling within each bin were then divided by 51 years to obtain the average number of hours per year for each flow bin. Figure 6 shows an example of the flow duration data developed for use in the MFA. Figure 6. Example flow duration density/distribution data for Upper Clarks Creek Data displayed as frequency totals for discrete intervals and as a continuous distribution curve. 0 20 40 60 80 100 120 140 160 180 200 0.01 0.10 1.00 10.00 100.00 Frequency (hours per year) Discharge (cfs) 0 20 40 60 80 100 120 140 160 180 200 0.01 0.10 1.00 10.00 100.00 Frequency (hours per year) Discharge (cfs) Figure 5. Example flow duration curve for Upper Clarks Creek 0.0 0.1 1.0 10.0 100.0 0% 20% 40% 60% 80% 100% Hourly Stream Discharge (cfs) Percent Time Exceeded ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Geomorphic Magnitude-Frequency Analysis 7 DRAFT for review purposes only. Use of contents on this sheet is subject to the limitations specified at the beginning of this document. CCSRAP E (GeomorphicMFA_TechMemo_20121121(v5))_track changes accepted.docx 3.1.2 Stream Channel Hydraulics MFA requires hydraulic parameters to estimate flow velocities and shear stresses exerted by various stream discharges. Uniform flow calculations were performed based on Manning’s equation and the continuity equation as described in Chow et al. (1988): 𝑉= 1.49 𝑛 𝑅 2 3 ൗ𝑆 1 2 ൗ 𝑄= 𝑉𝐴 𝑅= 𝐴 𝑃 where V is the flow velocity in (feet per second), n is the Manning’s roughness coefficient, R is the hydraulic radius, S = energy slope (assumed equal to the bed slope of the channel), Q is the design discharge (cubic feet per second), A is the cross-sectional area of flow (feet squared), and P is the wetted perimeter of the cross-section (feet) Effective work calculations in the MFA Spreadsheet Tool use stream discharge as the dependent variable and computations are based on the incremental flow bins described in the previous section. The above- described equations were used to calculate flow velocity, depth, and shear stress for each incremental discharge. To avoid the need for an iterative solution, extensive hydraulic lookup tables were created to relate discharge to hydraulic radius and cross-sectional flow area for each of the available stream cross- sections. Additional input values were obtained as follows: • Stream channel cross-sections: Cross-section surveys were conducted at 36 locations along the stream network, primarily in the upper reaches. Additional cross-section data were obtained from an existing hydraulic model developed for flood hazard mapping along lower Clarks Creek and lower Meeker Creek (NHC, 2005). In total, 54 cross-sections were available for use in calculating stream channel hydraulics (see Map 3, Attachment • Manning’s roughness: Manning’s roughness coefficients were estimated based on field observations using the general method presented in Chow (1959), which accounts for several factors, including chan- nel material, degree of irregularity, variation in channel cross-section, obstructions, vegetation, and meandering. Values ranged from 0.030 to 0.055. • Stream channel slopes: Topographic data for the entire Clarks Creek basin were obtained from the Puget Sound LiDAR Consortium (PSLC, 2011). PSLC data are developed from detailed Light Detection and Ranging (LiDAR) aerial surveys, and are provided in the form digital elevation models (DEMs), which are data grids formatted for use with geospatial information systems (GIS). The DEM obtained for the Clarks Creek basin has a 6-foot grid resolution. The LiDAR DEM data were used to create preliminary stream profiles by extracting elevations every 100 feet. The preliminary profiles were then adjusted to match the thalweg lowest point) elevations from the cross-section surveys described above. The adjusted stream profiles were used to calculate the average slope along any particular stream reach. The uniform flow calculations described above were used to estimate the hydraulic radius, which was then used to estimate mean channel shear stress as follows: 𝜏= 𝛾𝑅𝑆 where γ is the specific weight of the water, assumed to equal approximately 62.4 pounds per cubic foot ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Geomorphic Magnitude-Frequency Analysis 8 DRAFT for review purposes only. Use of contents on this sheet is subject to the limitations specified at the beginning of this document. CCSRAP E (GeomorphicMFA_TechMemo_20121121(v5))_track changes accepted.docx 3.1.3 Sediment Gradation Calculation of sediment transport or effective work on the stream channel requires characterization of the bed sediments in terms of the size and gradation of the material. Sediment gradation data were obtained through laboratory analyses of surficial bed sediment samples taken at 20 locations along Clarks Creek and its major tributaries (see Map 4, Attachment To apply the sediment gradation data more broadly throughout the stream network, the gradation curves were analyzed with respect to stream channel gradient slope) to discern general trends. Based on observations and our knowledge of typical fluvial conditions, it is expected that the bed sediments in the stream channels with low gradients will be finer than the bed sediments in the stream channels with steeper gradients. This general trend is observed in the gradation data from the sediment samples; however, six samples were visually deemed as outliers (see Figure The remaining sediment samples were divided into three classes: • Class 1 sediment samples were located in the steepest reaches (greater than 6 percent slope). • Class 2 sediment samples were located in moderately steep reaches (between 1 and 6 per- cent slope). • Class 3 sediment samples were located in the low-gradient reaches (less than 1 percent slope). Gradation data from the selected sediment samples were combined with equal weighting to create three composite gradation curves (see Figure Calculated mean particle diameters (D50) for each of the classes are provided in Table 1. Figure 7. Selection of bed sediment classes Of the 20 sediment samples, 14 showed a close correlation between stream channel gradient and mean particle size (R2 = 0.97); 6 samples were removed as outliers. Figure 8. Composite gradation curves for bed sediment classes Gradation curves calculated from selected sediment samples as shown in Figure 7. y = 0.0049x + 0.0004 R² = 0.9666 0.00 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0 5 10 15 Stream Channel Gradient Median Particle Size, D50 (mm) Removed as outliers Bed Sediment Class 1 Bed Sediment Class 2 Bed Sediment Class 3 Linear (Correlation) 0 10 20 30 40 50 60 70 80 90 100 0.001 0.010 0.100 1.000 10.000 100.000 Percent Finer by Wieght Particle Diameter (mm) Class 1 Class 2 Class 3 ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Geomorphic Magnitude-Frequency Analysis 9 DRAFT for review purposes only. Use of contents on this sheet is subject to the limitations specified at the beginning of this document. CCSRAP E (GeomorphicMFA_TechMemo_20121121(v5))_track changes accepted.docx Table 1. Sediment Characteristics for Composite Sediment Classes Composite sediment class Mean particle diameter D50 (mm) Sediment size description* Applicable slope range Class 1 13.7 Medium gravel Greater than 6% Class 2 7.2 Fine gravel Between 1% and 6% Class 3 0.14 Fine sand Less than 1% *As defined by the American Geophysical Union Sediment Classification System. Mean particle diameters for the bed sediments were used in combination with stream channel hydraulics to calculate sediment transport rates/effective work potential. 3.1.4 Effective Work Index In physics, work is defined as the integral of force over a distance of displacement. In the case of stream systems, work can be calculated based on stream power, or the product of flow velocity and shear stress. Total effective work was calculated using an effective work index defined as follows: 𝑊= 𝐶෍(𝜏𝑖−𝜏𝑐)𝑏∙𝑉𝑖 𝑛 𝑖=1 ∙Δ𝑡 where W is the index of total work done (units of foot-pounds per square foot), C is a constant to di- mensional or dimensionless units of work, n is the number of increments in the flow histogram, t is the applied hydraulic shear stress (pounds per square foot), tc is the critical shear stress that in- itiates bed movement (pounds per square foot), e is an exponent that captures the exponential rise in stream power with flow, V is the mid-channel flow velocity (feet per second), ∆t is the duration of flow for each time increment (seconds) The exponent, b, captures the exponential rise in stream power with increasing flow rates. For this analysis, b was assumed to be equal to 1.5, which is consistent with standard bedload transport functions such as the equation developed by Meyer-Peter and Muller (1948). Critical shear stress (τc) was calculated using the following equation: 𝜏𝑐= 𝜏∗(𝛾𝑠−𝛾)𝐷50 where τc = critical shear stress (pounds per square foot), τ∗ = dimensionless shear Shield’s parameter), γs = specific weight of the stone = 165 pounds per cubic foot, γ = specific weight of the water = 62.4 pounds per cubic foot, D50 = mean particle size from the sediment gradations curves (feet) Dimensionless shear was calculated using an approximation developed by Wilcock (2004): 0.105𝑆∗−0.3 + 𝑒−35𝑆∗−0.59 ඥ(𝛾𝑠𝛾 ⁄ ∗𝑔∗𝐷3 𝜐 ⁄ where S* is the dimensionless kinematic viscosity, g is the gravitational constant (assumed to be 32.2 feet per second squared), and υ is the kinematic viscosity of water (assumed to be 1.12 ×10-5 feet squared per second) ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Geomorphic Magnitude-Frequency Analysis 10 DRAFT for review purposes only. Use of contents on this sheet is subject to the limitations specified at the beginning of this document. CCSRAP E (GeomorphicMFA_TechMemo_20121121(v5))_track changes accepted.docx 3.2 Geomorphically Significant Flows Evaluation Geomorphically significant flows were calculated from the effective work curves using an assumed level of control (percentage of total work done). The calculation of the upper and lower bounds is described in Section 3.2.1. Regulatory thresholds related to Washington State flow control standards were also calcu- lated to provide context to the results (see Subsection 3.2.2). 3.2.1 Calculation of the Lower and Upper Bounds The qualitative description of the geomorphically significant flows presented by Leopold et al. (1964) suggests a lower limit at the flow rate necessary to produce incipient motion of bed sediments. However, incipient motion calculations based on critical shear stress (see Subsection 3.1.4) indicated that for many of the steep and incised stream reaches, the flow rate associated with incipient motion of the mean particle size was extremely small (less than 0.01 cubic feet per second [cfs]), and flows of that magnitude also tend to be intermittent and infrequent. A similar problem is presented by the upper limit; Leopold et al. (1964) describes the upper limit as the flow rate at which the bankfull capacity of the channel is exceeded. However, many of the incised stream reaches do not have a clear bankfull channel as they are effectively disconnected from adjacent floodplains or are located in steep ravines that do not have a well-developed floodplain or bankfull condition. Alternatively, a desired “level of control” was assumed based on the integral percentage of the effective work curve captured by the upper and lower bounds. For this study, that percentage was assumed to be 98 percent. The remaining 2 percent was divided evenly between the upper and lower “tails” of the effective work curve. 3.2.2 Regulatory Thresholds The National Pollutant Discharge Elimination System (NPDES) Permit program is a requirement of the federal Clean Water Act, which is intended to protect and restore waters for “fishable, swimmable” uses. The EPA has delegated Permit authority to state environmental agencies, and these agencies can set Permit conditions in accordance with, and in addition to, the minimum federal requirements. In Washington, the State Department of Ecology (Ecology) is the NPDES-delegated Permit authority. Ecology issues municipal stormwater permits to cover discharges from municipal separate storm sewer systems (MS4s). Pierce County and the City of Puyallup are the two MS4 jurisdictions located within the Clarks Creek basin. Pierce County is covered under the Phase I Municipal Stormwater Permit (Phase I Permit), and the City of Puyallup is covered by the Phase II Western Washington Stormwater Permit (Phase II Permit). On August 1, 2012, Ecology issued the Phase I and Phase II Permits for 2013 to 2018, due to become effective on August 1, 2013. 3.2.2.1 Flow Control Standards The 2013–18 Municipal Stormwater Permits contain special requirements for new development and re- development projects. Minimum Requirement 5 (On-site Stormwater Management) and Minimum Requirement 7 (Flow Control) specify flow duration control standards for mitigating flow increases cause by increased impervious surfaces. More specifically, • Minimum Requirement 5, “On-site Stormwater Management,” contains a low-impact development (LID) performance standard as follows: Stormwater discharges shall match developed discharge durations to pre-developed dura- tions for the range of pre-developed discharge rates from 8% of the 2-year peak flow to 50% of the 2-year peak flow. Refer to the Standard Flow Control Requirement section in Minimum Requirement #7 for information about the assignment of the pre-developed condition. ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Geomorphic Magnitude-Frequency Analysis 11 DRAFT for review purposes only. Use of contents on this sheet is subject to the limitations specified at the beginning of this document. CCSRAP E (GeomorphicMFA_TechMemo_20121121(v5))_track changes accepted.docx Project sites that must also meet minimum requirement #7 shall match flow durations be- tween 8% of the 2-year flow through the full 50-year flow. • Minimum Requirement 7: “Flow Control,” contains a standard flow control requirement as follows: Stormwater discharges shall match developed discharge durations to pre-developed dura- tions for the range of pre-developed discharge rates from 50% of the 2-year peak flow up to the full 50-year peak flow. The pre-developed condition to be matched shall be a forested land cover unless [specific conditions are met.] The intent behind Minimum Requirements 5 and 7 is to mitigate the impacts of increased stormwater flows through a range of flows that are considered geomorphically significant (as described in the previous subsection) such that erosive and unstable geomorphic conditions are minimized. The lower bound of the flow control standard corresponds roughly to the flow rate below which the effective work done on the channel is essentially negligible. 3.2.2.2 Discharges for the Pre-developed/Forested Condition The HSPF model developed by Tetra Tech (April 2012) was used to simulate a pre-developed, fully forested condition. Flow hydrographs were then processed into partial duration series to obtain a series of discrete runoff events. The peak flow rates from each of these events were ranked and assigned an exceedance probability using the following plotting position formula: 𝑃(𝑋≥𝑥𝑛) = 𝑚−𝑏 𝑛+ 1 −2𝑏 where P(X ≥ xm) = exceedance probability, m = rank of event, n = number of years of record, and b = plotting parameter The plotting parameter used for this analysis was based on Cunnane (1978) as presented in (Maidment, 1993), where b is equal to 0.4. The calculated exceedance probability was converted to a return period, or recurrence interval (Tr) using the following equation: 𝑇𝑟= 1 𝑃(𝑋≥𝑥𝑚) Two-year discharges for forested conditions were calculated and multiplied by 0.08 and 0.5 to calculate the lower flow thresholds for Minimum Requirements 5 and 7, respectively. ---PAGE BREAK--- ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Geomorphic Magnitude-Frequency Analysis 12 DRAFT for review purposes only. Use of contents on this sheet is subject to the limitations specified at the beginning of this document. CCSRAP E (GeomorphicMFA_TechMemo_20121121(v5))_track changes accepted.docx 4. Results and Discussion Stream profile plots were used to divide Clarks, Rody, Diru, Woodland, Silver, and Meeker creeks into computational stream reaches. The MFA Spreadsheet Tool was then used to calculate geomorphically significant flow ranges for each reach. Input data for each reach were selected based on the nearest relevant data point (see Maps 2 through 4, Attachment One-page results summaries for each reach are provided in Attachment B. Additional tabulated results comparing the calculated geomorphically significant flow bounds with forested-conditions regulatory thresholds are provided in Attachment C. The following general trends were observed in the results: • Calculated geomorphically significant flows vary widely within the Clarks Creek watershed. • Calculated geomorphically significant flows for lower Clarks Creek (reaches CC-R01 through CC-R16) roughly correspond to the flow thresholds of Minimum Requirement 7; i.e., 50 percent of the 2-year fo- rested discharge through the approximately the 50-year forested discharge (see Figure • Calculated geomorphically significant flows for upper Clarks Creek (reaches CC-R17 through CC-R23) vary; the lower bound ranges from 5 percent of the 2-year forested discharge up to about 38 percent of the 2-year forested discharge (see Figure 10). The upper bound tends to be two to three times larger than the 50-year forested discharge, likely due to the flow increases caused by urbanization. • Calculated geomorphically significant flows for the tributaries vary widely from reach to reach. The lower bound ranges from as little as 5 percent of the 2-year forested discharge to greater than 100 percent of the 2-year forested discharge (see Map 5, Attachment The upper bound can be as much as six times larger than the 50-year forested discharge, likely due to the flow increases caused by urbanization. Given the wide range of geomorphically significant flows, it would be difficult to establish a “one size fits all” flow control standard tailored to the Clarks Creek watershed. Flow control standards designed to arrest erosion in the most unstable stream reaches would require flows to be controlled down to an extremely low threshold, which given the poor soils and limited opportunities for detention in the upper watershed, is likely to be infeasible. The geomorphically significant flow analysis does suggest that the default standards described in Minimum Requirements 5 and 7 of the MS4 Permits would be a substantial improvement in the current flow regime and help to mitigate the potential for future channel instabilities. ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Geomorphic Magnitude-Frequency Analysis 13 DRAFT for review purposes only. Use of contents on this sheet is subject to the limitations specified at the beginning of this document. CCSRAP E (GeomorphicMFA_TechMemo_20121121(v5))_track changes accepted.docx Figure 9. Example MFA results plot for lower Clarks Creek (Reach CC-R01) Figure 10. Example MFA results plot for upper Clarks Creek (Reach CC-R21) 0.00 0.00 0.00 0.01 0.01 0.01 0.01 0.01 0.02 0.0% 1.0% 2.0% 3.0% 4.0% 5.0% 6.0% 7.0% 1.00 10.00 100.00 1000.00 Sediment Transport Rate (ft3/s/ft) Normalized Flow and Sediment Curves Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 0.00 0.20 0.40 0.60 0.80 1.00 1.20 0.0% 0.5% 1.0% 1.5% 2.0% 2.5% 0.00 0.01 0.10 1.00 10.00 100.00 Sediment Transport Rate (ft3/s/ft) Normalized Flow and Sediment Curves Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Geomorphic Magnitude-Frequency Analysis 14 DRAFT for review purposes only. Use of contents on this sheet is subject to the limitations specified at the beginning of this document. CCSRAP E (GeomorphicMFA_TechMemo_20121121(v5))_track changes accepted.docx References Bledsoe, B.P. and C.C. Watson. April 2001. “Effects of Urbanization on Channel Stability.” Journal of the American Water Resources Association; Vol. 37, No. 2, p. 255–270. Booth, D. B. 1990. “Stream-channel incision following drainage-basin urbanization.” Water Resources Bulletin; v. 26, p. 407– 417. Chow, V.T. 1959. “Open-Channel Hydraulics.” McGraw-Hill Companies. Cunnane, C. 1978. “Unbiased Plotting Positions – A Review.” Journal of Hydrology; Vol. 37, No. ¾, p. 205–222. Lane, E. 1955. “The Importance Of Fluvial Morphology in Hydraulic Engineering.” Proceedings, American Society of Civil Engineers, No. 745, July 1955. Leopold, L.B., M.G. Wolman and J.P. Miller. 1964. Fluvial Processes in Geomorphology. Dover Publications, Inc., New York, 1964. Maidment, D.R. 1993. Handbook of Hydrology. McGraw-Hill, Inc. New York. Meyer-Peter, E. and R. Muller. 1948. “Formulas for Bedload Transport.” Proceedings 2nd Meeting IAHR, Stockholm, 39–64. Northwest Hydraulic Consultants Inc. (NHC). June 2005. Draft Flood Insurance Mapping Study for Clarks Creek near Puyallup, Washington Pierce County, WA and Incorporated Areas, Community Number – 530138. Prepared for the Federal Emer- gency Management Agency (FEMA) Prepared by Northwest Hydraulic Consultants Inc., 16300 Christensen Road, Suite 350, Seattle, Washington 98188-3418. Puget Sound LiDAR Consortium (PSLC). 2011. Digital Elevation Models. URL: http://pugetsoundlidar.ess.washington.edu/. Tetra Tech. April 4, 2012. Clarks Creek Sediment Study Watershed Model Report – Revised Draft. Prepared for the Puyallup Tribe of Indians by Tetra Tech, 3200 Chapel Hill-Nelson Hwy, Suite 105, PO Box 14409, Research Triangle Park, North Carolina 27709. Tetra Tech. May 11, 2012 Memorandum from Jon Butcher to Clarks Creek Project Team titled Clarks Creek Allocation Accounting. Prepared by Tetra Tech, 3200 Chapel Hill-Nelson Hwy, Suite 105, P.O. Box 14409, Research Triangle Park, North Carolina 27709. Wolman, M.G., and J.P. Miller. 1960. “Magnitude And Frequency of Forces in Geomorphic Processes.” Journal of Geology; v. 68, p. 54–74. Wilcock, Peter. (2004) Sediment Transport Seminar, January 26–28, 2004 at University of California at Berkeley. ---PAGE BREAK--- ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Geomorphic Magnitude-Frequency Analysis A DRAFT for review purposes only. Use of contents on this sheet is subject to the limitations specified at the beginning of this document. CCSRAP E (GeomorphicMFA_TechMemo_20121121(v5))_track changes accepted.docx Attachment A: Maps Map 1: Computational Stream Reaches Map 2: Flow Output Locations Map 3: Cross-section Locations Map 4: Sediment Sampling Locations Map 5: Geomorphically Significant Flow Lower Bounds ---PAGE BREAK--- This page intentionally left blank. ---PAGE BREAK--- Stewart Ave River Rd 104th St E Canyon Rd E 96th St E 90th St E Pioneer Way Woodland Ave E Fruitland S Meridian 72nd St E 9th St SW 52nd St E 76th Ave E 84th St E 31st Ave SW Hwy 512 MC%R05 RC%R02 CC%R01 CC%R05 UMW%R01 UMW%R02 DC%R10 CC%R13 RC%R10 CC%R11 CC%R25 CC%R12 CC%R14 SC%R09 SC%R08 DC%R08 DC%R01 RC%R09 UCT%R01 WC%R12 MC%R03 SC%R01 CC%R02 DC%R07 CC%R16 MC%R01 CC%R08 WC%R10 CC%R10 MC%R02 CC%R03 CC%R17 CC%R18 RC%R06 RC%R01 WC%R01 WC%R09 WC%R11 CC%R15 CC%R09 DC%R06 DC%R05 DC%R04 CC%R06 WC%R05 SC%R07 DC%R02 SC%R05 SC%R06 WC%R04 UME%R03 SC%R02 WC%R08 RC%R07 RC%R04 RC%R08 MC%R04 CC%R07 CC%R04 WC%R02 SC%R04 CC%R23 DC%R03 WC%R07 RC%R05 DC%R09 WC%R06 UMW%R03 UME%R06 CC%R21 UMW%R05 CC%R19 CC%R22 SC%R03 RC%R03 CC%R24 UME%R01 UMW%R04 UME%R05 UME%R04 WC%R03 CC%R20 UME%R02 Rod y Cr eek Diru Creek Wood land Creek Cl a rk s C r e e k Silver Cre e k Meeker Creek Puyallup River THIS DRAWING OR FILE HAS BEEN PREPARED BY BROWN AND CALDWELL FOR ITS CLIENT AND MAY NOT BE COPIED OR USED WITHOUT WRITTEN AUTHORIZATION. DUE TO THE ALTERABLE NATURE OF ELECTRONIC MATERIALS, RECIPIENT SHOULD NOT RELY ON THIS FOR ACCURACY OR CONTENT, AND ACKNOWLEDGES AND AGREES IT HAS BEEN PROVIDED SOLELY FOR CONVENIENCE AND INFORMATIONAL PURPOSES. BROWN AND CALDWELL MAKES NO REPRESENTATIONS REGARDING SUITABILITY OR FITNESS FOR A PARTICULAR PURPOSE. 1,200 0 1,200 FT 1 inch = 2,400 feet MAP 1 MAP 1 MAP 1 MAP 1 REACHES FOR REACHES FOR REACHES FOR REACHES FOR MFA COMPUTATION MFA COMPUTATION MFA COMPUTATION MFA COMPUTATION CLARKS CREEK SEDIMENT CLARKS CREEK SEDIMENT CLARKS CREEK SEDIMENT CLARKS CREEK SEDIMENT REDUCTION ACTION PLAN REDUCTION ACTION PLAN REDUCTION ACTION PLAN REDUCTION ACTION PLAN F L E G E N D Evaluation Reaches Path: P:\Puyallup Tribe\140982 Clarks Sediment Study\GIS\projects\MFA\CCSS MFA Inputs Map01 (21Nov2012).mxd Author: NFoged 11/21/2012 ---PAGE BREAK--- Stewart Ave River Rd 104th St E Canyon Rd E 96th St E 90th St E Pioneer Way Woodland Ave E Fruitland S Meridian d St E 9th St SW 52nd St E 76th Ave E 84th St E 31st Ave SW MC$R05 RC$R02 CC$R01 CC$R05 UMW$R01 UMW$R02 DC$R10 CC$R13 RC$R10 CC$R11 CC$R25 CC$R12 CC$R14 SC$R09 SC$R08 DC$R08 DC$R01 RC$R09 UCT$R01 WC$R12 MC$R03 SC$R01 CC$R02 DC$R07 CC$R16 MC$R01 CC$R08 WC$R10 CC$R10 MC$R02 CC$R03 CC$R17 CC$R18 RC$R06 RC$R01 WC$R01 WC$R09 WC$R11 CC$R15 CC$R09 DC$R06 DC$R05 DC$R04 CC$R06 WC$R05 SC$R07 DC$R02 SC$R05 SC$R06 WC$R04 UME$R03 SC$R02 WC$R08 RC$R07 RC$R04 RC$R08 MC$R04 CC$R07 CC$R04 WC$R02 SC$R04 CC$R23 DC$R03 WC$R07 RC$R05 DC$R09 WC$R06 UMW$R03 UME$R06 CC$R21 UMW$R05 CC$R19 CC$R22 SC$R03 RC$R03 CC$R24 UME$R01 UMW$R04 UME$R05 UME$R04 WC$R03 CC$R20 UME$R02 Rod y Cr eek Diru Creek Wood land Creek Cl a rk s C r e e k Silver Cre e k Meeker Creek Puyallup River MC$Q04 SC$Q01 MC$Q01 SC$Q04 CC$Q10 WC$Q04 DC$Q04 RC$Q04 CC$Q06 RC$Q03 MC$Q02 MC$Q03 SC$Q02 SC$Q03 CC$Q01 CC$Q02 CC$Q03 CC$Q04 CC$Q05 CC$Q09 CC$Q07 CC$Q08 WC$Q01 WC$Q02 WC$Q03 DC$Q01 DC$Q02 DC$Q03 RC$Q01 RC$Q02 UMW$Q01 UME$Q02 UMW$Q03 UME$Q01 UMW$Q02 UCT$Q02 THIS DRAWING OR FILE HAS BEEN PREPARED BY BROWN AND CALDWELL FOR ITS CLIENT AND MAY NOT BE COPIED OR USED WITHOUT WRITTEN AUTHORIZATION. DUE TO THE ALTERABLE NATURE OF ELECTRONIC MATERIALS, RECIPIENT SHOULD NOT RELY ON THIS FOR ACCURACY OR CONTENT, AND ACKNOWLEDGES AND AGREES IT HAS BEEN PROVIDED SOLELY FOR CONVENIENCE AND INFORMATIONAL PURPOSES. BROWN AND CALDWELL MAKES NO REPRESENTATIONS REGARDING SUITABILITY OR FITNESS FOR A PARTICULAR PURPOSE. 1,200 0 1,200 FT 1 inch = 2,400 feet MAP 2 MAP 2 MAP 2 MAP 2 STREAM FLOW STREAM FLOW STREAM FLOW STREAM FLOW OUTPUT NODES OUTPUT NODES OUTPUT NODES OUTPUT NODES CLARKS CREEK SEDIMENT CLARKS CREEK SEDIMENT CLARKS CREEK SEDIMENT CLARKS CREEK SEDIMENT REDUCTION ACTION PLAN REDUCTION ACTION PLAN REDUCTION ACTION PLAN REDUCTION ACTION PLAN F L E G E N D Flow Output Node Evaluation Reaches Path: P:\Puyallup Tribe\140982 Clarks Sediment Study\GIS\projects\MFA\CCSS MFA Inputs Map03 (27Aug2012).mxd Author: NFoged 11/21/2012 ---PAGE BREAK--- D D D D D D D D D D D D DD D DD D D D D D D D D D D D D D D D D D D Stewart Ave River Rd 104th St E Canyon Rd E 96th St E 90th St E Pioneer Way Woodland Ave E Fruitland S Meridian d St E 9th St SW 52nd St E 76th Ave E 84th St E 31st Ave SW MC$R05 RC$R02 CC$R01 CC$R05 UMW$R01 UMW$R02 DC$R10 CC$R13 RC$R10 CC$R11 CC$R25 CC$R12 CC$R14 SC$R09 SC$R08 DC$R08 DC$R01 RC$R09 UCT$R01 WC$R12 MC$R03 SC$R01 CC$R02 DC$R07 CC$R16 MC$R01 CC$R08 WC$R10 CC$R10 MC$R02 CC$R03 CC$R17 CC$R18 RC$R06 RC$R01 WC$R01 WC$R09 WC$R11 CC$R15 CC$R09 DC$R06 DC$R05 DC$R04 CC$R06 WC$R05 SC$R07 DC$R02 SC$R05 SC$R06 WC$R04 UME$R03 SC$R02 WC$R08 RC$R07 RC$R04 RC$R08 MC$R04 CC$R07 CC$R04 WC$R02 SC$R04 CC$R23 DC$R03 WC$R07 RC$R05 DC$R09 WC$R06 UMW$R03 UME$R06 CC$R21 UMW$R05 CC$R19 CC$R22 SC$R03 RC$R03 CC$R24 UME$R01 UMW$R04 UME$R05 UME$R04 WC$R03 CC$R20 UME$R02 Rod y Cr eek Diru Creek Wood land Creek Cl a rk s C r e e k Silver Cre e k Meeker Creek Puyallup River BC13 BC04 BC03 BC02 BC05 BC01 BC08 BC06 BC09 BC11 XS 473 XS 446 XS 456 XS 468 XS 440 XS 437 XS 430 XS 430 XS 423 XS 422 XS 421 XS 477 XS 414 XS 416 XS 418 XS 488 XS 485 THIS DRAWING OR FILE HAS BEEN PREPARED BY BROWN AND CALDWELL FOR ITS CLIENT AND MAY NOT BE COPIED OR USED WITHOUT WRITTEN AUTHORIZATION. DUE TO THE ALTERABLE NATURE OF ELECTRONIC MATERIALS, RECIPIENT SHOULD NOT RELY ON THIS FOR ACCURACY OR CONTENT, AND ACKNOWLEDGES AND AGREES IT HAS BEEN PROVIDED SOLELY FOR CONVENIENCE AND INFORMATIONAL PURPOSES. BROWN AND CALDWELL MAKES NO REPRESENTATIONS REGARDING SUITABILITY OR FITNESS FOR A PARTICULAR PURPOSE. 1,200 0 1,200 FT 1 inch = 2,400 feet MAP 3 MAP 3 MAP 3 MAP 3 CROSS SECTION CROSS SECTION CROSS SECTION CROSS SECTION LOCATIONS LOCATIONS LOCATIONS LOCATIONS CLARKS CREEK SEDIMENT CLARKS CREEK SEDIMENT CLARKS CREEK SEDIMENT CLARKS CREEK SEDIMENT REDUCTION ACTION PLAN REDUCTION ACTION PLAN REDUCTION ACTION PLAN REDUCTION ACTION PLAN F L E G E N D Evaluation Reaches D New Surveyed Cross$section Path: P:\Puyallup Tribe\140982 Clarks Sediment Study\GIS\projects\MFA\CCSS MFA Inputs Map03 (21Nov2012).mxd Author: NFoged 11/21/2012 ---PAGE BREAK--- Stewart Ave River Rd 104th St E Canyon Rd E 96th St E 90th St E Pioneer Way Woodland Ave E Fruitland S Meridian d St E 9th St SW 52nd St E 76th Ave E 84th St E 31st Ave SW MC$R05 RC$R02 CC$R01 CC$R05 UMW$R01 UMW$R02 DC$R10 CC$R13 RC$R10 CC$R11 CC$R25 CC$R12 CC$R14 SC$R09 SC$R08 DC$R08 DC$R01 RC$R09 UCT$R01 WC$R12 MC$R03 SC$R01 CC$R02 DC$R07 CC$R16 MC$R01 CC$R08 WC$R10 CC$R10 MC$R02 CC$R03 CC$R17 CC$R18 RC$R06 RC$R01 WC$R01 WC$R09 WC$R11 CC$R15 CC$R09 DC$R06 DC$R05 DC$R04 CC$R06 WC$R05 SC$R07 DC$R02 SC$R05 SC$R06 WC$R04 UME$R03 SC$R02 WC$R08 RC$R07 RC$R04 RC$R08 MC$R04 CC$R07 CC$R04 WC$R02 SC$R04 CC$R23 DC$R03 WC$R07 RC$R05 DC$R09 WC$R06 UMW$R03 UME$R06 CC$R21 UMW$R05 CC$R19 CC$R22 SC$R03 RC$R03 CC$R24 UME$R01 UMW$R04 UME$R05 UME$R04 WC$R03 CC$R20 UME$R02 Rod y Cr eek Diru Creek Wood land Creek Cl a rk s C r e e k Silver Cre e k Meeker Creek Puyallup River RODY02 WOOD01 EAST01 DIRU01 WEST01 RODY03 RODY01 SILVER01 CLARKS03 SILVER03 SILVER02 CLARKS04 CLARKS02 CLARKS01 CLARKS05 CLARKS06 CLARKS07 CLARKS10 CLARKS08 CLARKS09 THIS DRAWING OR FILE HAS BEEN PREPARED BY BROWN AND CALDWELL FOR ITS CLIENT AND MAY NOT BE COPIED OR USED WITHOUT WRITTEN AUTHORIZATION. DUE TO THE ALTERABLE NATURE OF ELECTRONIC MATERIALS, RECIPIENT SHOULD NOT RELY ON THIS FOR ACCURACY OR CONTENT, AND ACKNOWLEDGES AND AGREES IT HAS BEEN PROVIDED SOLELY FOR CONVENIENCE AND INFORMATIONAL PURPOSES. BROWN AND CALDWELL MAKES NO REPRESENTATIONS REGARDING SUITABILITY OR FITNESS FOR A PARTICULAR PURPOSE. 1,200 0 1,200 FT 1 inch = 2,400 feet MAP 4 MAP 4 MAP 4 MAP 4 SEDIMENT SAMPLING SEDIMENT SAMPLING SEDIMENT SAMPLING SEDIMENT SAMPLING LOCATIONS LOCATIONS LOCATIONS LOCATIONS CLARKS CREEK SEDIMENT CLARKS CREEK SEDIMENT CLARKS CREEK SEDIMENT CLARKS CREEK SEDIMENT REDUCTION ACTION PLAN REDUCTION ACTION PLAN REDUCTION ACTION PLAN REDUCTION ACTION PLAN F L E G E N D Sediment Samples Evaluation Reaches Path: P:\Puyallup Tribe\140982 Clarks Sediment Study\GIS\projects\MFA\CCSS MFA Inputs Map04 (21Nov2012).mxd Author: NFoged 11/21/2012 ---PAGE BREAK--- Stewart Ave River Rd 104th St E Canyon Rd E 96th St E 90th St E Pioneer Way Woodland Ave E Fruitland S Meridian d St E 9th St SW 52nd St E 76th Ave E 84th St E 31st Ave SW MC$R05 RC$R02 CC$R01 CC$R05 UMW$R01 UMW$R02 DC$R10 CC$R13 RC$R10 CC$R11 CC$R25 CC$R12 CC$R14 SC$R09 SC$R08 DC$R08 DC$R01 RC$R09 UCT$R01 WC$R12 MC$R03 SC$R01 CC$R02 DC$R07 CC$R16 MC$R01 CC$R08 WC$R10 CC$R10 MC$R02 CC$R03 CC$R17 CC$R18 RC$R06 RC$R01 WC$R01 WC$R09 WC$R11 CC$R15 CC$R09 DC$R06 DC$R05 DC$R04 CC$R06 WC$R05 SC$R07 DC$R02 SC$R05 SC$R06 WC$R04 UME$R03 SC$R02 WC$R08 RC$R07 RC$R04 RC$R08 MC$R04 CC$R07 CC$R04 WC$R02 SC$R04 CC$R23 DC$R03 WC$R07 RC$R05 DC$R09 WC$R06 UMW$R03 UME$R06 CC$R21 UMW$R05 CC$R19 CC$R22 SC$R03 RC$R03 CC$R24 UME$R01 UMW$R04 UME$R05 UME$R04 WC$R03 CC$R20 UME$R02 Rod y Cr eek Diru Creek Wood land Creek Cl a rk s C r e e k Silver Cre e k Meeker Creek Puyallup River THIS DRAWING OR FILE HAS BEEN PREPARED BY BROWN AND CALDWELL FOR ITS CLIENT AND MAY NOT BE COPIED OR USED WITHOUT WRITTEN AUTHORIZATION. DUE TO THE ALTERABLE NATURE OF ELECTRONIC MATERIALS, RECIPIENT SHOULD NOT RELY ON THIS FOR ACCURACY OR CONTENT, AND ACKNOWLEDGES AND AGREES IT HAS BEEN PROVIDED SOLELY FOR CONVENIENCE AND INFORMATIONAL PURPOSES. BROWN AND CALDWELL MAKES NO REPRESENTATIONS REGARDING SUITABILITY OR FITNESS FOR A PARTICULAR PURPOSE. 1,200 0 1,200 FT 1 inch = 2,400 feet MAP 4 MAP 4 MAP 4 MAP 4 GEO. SIG. FLOW GEO. SIG. FLOW GEO. SIG. FLOW GEO. SIG. FLOW LOWER FLOW BOUND LOWER FLOW BOUND LOWER FLOW BOUND LOWER FLOW BOUND CLARKS CREEK SEDIMENT CLARKS CREEK SEDIMENT CLARKS CREEK SEDIMENT CLARKS CREEK SEDIMENT REDUCTION ACTION PLAN REDUCTION ACTION PLAN REDUCTION ACTION PLAN REDUCTION ACTION PLAN F L E G E N D Evaluation Reaches Lower Flow Bound Relative to 2Year Forested Discharge 10% 20% 30% 40% 50% 60% 100% Path: P:\Puyallup Tribe\140982 Clarks Sediment Study\GIS\projects\MFA\CCSS MFA Inputs Map05 (21Nov2012).mxd Author: NFoged 11/21/2012 ---PAGE BREAK--- ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Geomorphic Magnitude-Frequency Analysis B DRAFT for review purposes only. Use of contents on this sheet is subject to the limitations specified at the beginning of this document. CCSRAP E (GeomorphicMFA_TechMemo_20121121(v5))_track changes accepted.docx Attachment B: Reach Summaries ---PAGE BREAK--- This page intentionally left blank. ---PAGE BREAK--- MFA Inputs Reach: CCR01 Flow location: CCQ01 Crosssection: CC.0033 Channel Slope: 0.2% Sediment sample: Class 3 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.07 0.07 0.07 0.07 62.44 63.78 2% Q50 164.22 164.2 80.96 180.19 123% Q2 80.96 80.96 164.22 784.17 378% 0.5Q2 40.48 40.48 40.48 90.10 0.08Q2 6.48 6.48 6.48 14.42 0.49Q2 39.47 39.47 1.13Q50 185.54 185.54 Incipient Motion of Sediments 0.00 0.02 2.65 0.02 0.05 0.28 0.0000 0.000 0.03 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.01 0.01 0.01 0.01 0.02 3.0% 4.0% 5.0% 6.0% 7.0% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 48,261 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 185.54 Lower flow bound for sediment loading (cfs): 39.47 Upper flow bound as a fraction of 50year flow*: 1.13 Lower flow bound as a fraction of 2year flow*: 0.488 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 64.69 Flow depth at effective discharge (ft): 1.49 Shear Stress at effective discharge (lb/ft 0.15 Average flow velocity at effective discharge (ft/s): 2.0 Shear velocity at effective discharge (ft/s): 0.3 Effective width at effective discharge (ft): 25.2 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Fine gravel Medium sand Coarse sand 0.00 0.00 0.00 0.01 0.0% 1.0% 2.0% 3.0% 1.00 10.00 100.00 1000.00 10000.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: CCR02 Flow location: CCQ01 Crosssection: CC.0347 Channel Slope: 0.1% Sediment sample: Class 3 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.07 0.07 0.07 0.07 62.44 63.78 2% Q50 164.22 164.2 80.96 180.19 123% Q2 80.96 80.96 164.22 784.17 378% 0.5Q2 40.48 40.48 40.48 90.10 0.08Q2 6.48 6.48 6.48 14.42 0.49Q2 39.47 39.47 1.13Q50 185.54 185.54 Incipient Motion of Sediments 0.00 0.01 4.75 0.03 0.09 0.90 0.0000 0.000 0.06 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.00 0.00 0.01 0.01 0.01 3.0% 4.0% 5.0% 6.0% 7.0% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 21,338 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 185.54 Lower flow bound for sediment loading (cfs): 39.47 Upper flow bound as a fraction of 50year flow*: 1.13 Lower flow bound as a fraction of 2year flow*: 0.488 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 64.69 Flow depth at effective discharge (ft): 2.21 Shear Stress at effective discharge (lb/ft 0.10 Average flow velocity at effective discharge (ft/s): 1.6 Shear velocity at effective discharge (ft/s): 0.2 Effective width at effective discharge (ft): 27.3 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Very fine gravel Fine sand Medium sand 0.00 0.00 0.00 0.00 0.0% 1.0% 2.0% 3.0% 1.00 10.00 100.00 1000.00 10000.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: CCR03 Flow location: CCQ01 Crosssection: CC.0539 Channel Slope: 0.1% Sediment sample: Class 3 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.07 0.07 0.07 0.07 62.44 63.78 2% Q50 164.22 164.2 80.96 180.19 123% Q2 80.96 80.96 164.22 784.17 378% 0.5Q2 40.48 40.48 40.48 90.10 0.08Q2 6.48 6.48 6.48 14.42 0.49Q2 39.47 39.47 1.13Q50 185.54 185.54 Incipient Motion of Sediments 0.00 0.01 10.96 0.05 0.11 1.23 0.0000 0.000 0.14 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.00 0.00 0.00 0.00 3.0% 4.0% 5.0% 6.0% 7.0% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 12,954 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 185.54 Lower flow bound for sediment loading (cfs): 39.47 Upper flow bound as a fraction of 50year flow*: 1.13 Lower flow bound as a fraction of 2year flow*: 0.488 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 64.69 Flow depth at effective discharge (ft): 2.16 Shear Stress at effective discharge (lb/ft 0.07 Average flow velocity at effective discharge (ft/s): 1.3 Shear velocity at effective discharge (ft/s): 0.2 Effective width at effective discharge (ft): 36.9 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Very fine gravel Fine sand Medium sand 0.00 0.00 0.00 0.0% 1.0% 2.0% 3.0% 1.00 10.00 100.00 1000.00 10000.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: CCR04 Flow location: CCQ01 Crosssection: CC.0761 Channel Slope: 0.1% Sediment sample: Class 3 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.07 0.07 0.07 0.07 62.44 63.78 2% Q50 164.22 164.2 80.96 180.19 123% Q2 80.96 80.96 164.22 784.17 378% 0.5Q2 40.48 40.48 40.48 90.10 0.08Q2 6.48 6.48 6.48 14.42 0.49Q2 39.47 39.47 1.06Q50 173.72 173.72 Incipient Motion of Sediments Very Small Very Small Very Small Very Small Very Small Very Small NA NA NA Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.02 0.03 0.03 0.04 0.04 3.0% 4.0% 5.0% 6.0% 7.0% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 41,309 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 173.72 Lower flow bound for sediment loading (cfs): 39.47 Upper flow bound as a fraction of 50year flow*: 1.06 Lower flow bound as a fraction of 2year flow*: 0.488 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 64.69 Flow depth at effective discharge (ft): 0.18 Shear Stress at effective discharge (lb/ft 0.84 Average flow velocity at effective discharge (ft/s): 7.4 Shear velocity at effective discharge (ft/s): 0.7 Effective width at effective discharge (ft): 0.4 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: #N/A Very coarse sand Very fine gravel 0.00 0.01 0.01 0.02 0.0% 1.0% 2.0% 3.0% 1.00 10.00 100.00 1000.00 10000.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: CCR05 Flow location: CCQ02 Crosssection: CC.0875 Channel Slope: 0.1% Sediment sample: Class 3 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.05 0.05 0.05 0.05 60.21 61.29 2% Q50 147.50 147.5 80.69 174.65 116% Q2 80.69 80.69 147.50 632.11 329% 0.5Q2 40.35 40.35 40.35 87.33 0.08Q2 6.46 6.46 6.46 13.97 0.48Q2 38.46 38.46 1.08Q50 159.33 159.33 Incipient Motion of Sediments 0.00 0.05 9.00 0.05 0.13 0.94 0.0001 0.001 0.11 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.00 0.00 0.00 0.00 0.00 0.00 3.0% 4.0% 5.0% 6.0% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 10,317 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 159.33 Lower flow bound for sediment loading (cfs): 38.46 Upper flow bound as a fraction of 50year flow*: 1.08 Lower flow bound as a fraction of 2year flow*: 0.477 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 62.30 Flow depth at effective discharge (ft): 2.24 Shear Stress at effective discharge (lb/ft 0.07 Average flow velocity at effective discharge (ft/s): 1.4 Shear velocity at effective discharge (ft/s): 0.2 Effective width at effective discharge (ft): 29.2 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Very fine gravel Fine sand Medium sand 0.00 0.00 0.00 0.00 0.00 0.0% 1.0% 2.0% 1.00 10.00 100.00 1000.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: CCR06 Flow location: CCQ02 Crosssection: CC.1102 Channel Slope: 0.1% Sediment sample: Class 3 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.05 0.05 0.05 0.05 60.21 61.29 2% Q50 147.50 147.5 80.69 174.65 116% Q2 80.69 80.69 147.50 632.11 329% 0.5Q2 40.35 40.35 40.35 87.33 0.08Q2 6.46 6.46 6.46 13.97 0.48Q2 38.46 38.46 1.05Q50 155.34 155.34 Incipient Motion of Sediments 0.00 0.01 2.01 0.05 0.12 1.00 0.0000 0.000 0.02 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.00 0.00 0.00 0.00 0.00 3.0% 4.0% 5.0% 6.0% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 14,193 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 155.34 Lower flow bound for sediment loading (cfs): 38.46 Upper flow bound as a fraction of 50year flow*: 1.05 Lower flow bound as a fraction of 2year flow*: 0.477 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 62.30 Flow depth at effective discharge (ft): 3.64 Shear Stress at effective discharge (lb/ft 0.08 Average flow velocity at effective discharge (ft/s): 1.6 Shear velocity at effective discharge (ft/s): 0.2 Effective width at effective discharge (ft): 23.0 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Very fine gravel Fine sand Medium sand 0.00 0.00 0.00 0.00 0.0% 1.0% 2.0% 1.00 10.00 100.00 1000.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: CCR07 Flow location: CCQ02 Crosssection: CC.1242 Channel Slope: 0.1% Sediment sample: Class 3 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.05 0.05 0.05 0.05 60.21 61.29 2% Q50 147.50 147.5 80.69 174.65 116% Q2 80.69 80.69 147.50 632.11 329% 0.5Q2 40.35 40.35 40.35 87.33 0.08Q2 6.46 6.46 6.46 13.97 0.48Q2 38.46 38.46 1.11Q50 163.43 163.43 Incipient Motion of Sediments 0.01 0.05 4.00 0.04 0.10 0.71 0.0001 0.001 0.05 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.00 0.00 0.00 0.00 3.0% 4.0% 5.0% 6.0% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 14,657 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 163.43 Lower flow bound for sediment loading (cfs): 38.46 Upper flow bound as a fraction of 50year flow*: 1.11 Lower flow bound as a fraction of 2year flow*: 0.477 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 62.30 Flow depth at effective discharge (ft): 2.56 Shear Stress at effective discharge (lb/ft 0.09 Average flow velocity at effective discharge (ft/s): 1.6 Shear velocity at effective discharge (ft/s): 0.2 Effective width at effective discharge (ft): 21.4 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Very fine gravel Fine sand Medium sand 0.00 0.00 0.00 0.0% 1.0% 2.0% 1.00 10.00 100.00 1000.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: CCR08 Flow location: CCQ03 Crosssection: CC.1372 Channel Slope: 0.1% Sediment sample: Class 3 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.05 0.05 0.05 0.05 58.65 59.63 2% Q50 131.24 131.2 77.70 161.72 108% Q2 77.70 77.70 131.24 524.04 299% 0.5Q2 38.85 38.85 38.85 80.86 0.08Q2 6.22 6.22 6.22 12.94 0.48Q2 37.40 37.40 1.11Q50 145.63 145.63 Incipient Motion of Sediments 0.01 0.06 10.00 0.06 0.14 1.06 0.0001 0.001 0.13 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.00 0.00 0.00 0.00 3.0% 4.0% 5.0% 6.0% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 9,351 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 145.63 Lower flow bound for sediment loading (cfs): 37.40 Upper flow bound as a fraction of 50year flow*: 1.11 Lower flow bound as a fraction of 2year flow*: 0.481 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 60.26 Flow depth at effective discharge (ft): 2.23 Shear Stress at effective discharge (lb/ft 0.06 Average flow velocity at effective discharge (ft/s): 1.3 Shear velocity at effective discharge (ft/s): 0.2 Effective width at effective discharge (ft): 28.7 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Very fine gravel Fine sand Medium sand 0.00 0.00 0.00 0.0% 1.0% 2.0% 1.00 10.00 100.00 1000.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: CCR09 Flow location: CCQ03 Crosssection: CC.1633 Channel Slope: 0.1% Sediment sample: Class 3 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.05 0.05 0.05 0.05 58.65 59.63 2% Q50 131.24 131.2 77.70 161.72 108% Q2 77.70 77.70 131.24 524.04 299% 0.5Q2 38.85 38.85 38.85 80.86 0.08Q2 6.22 6.22 6.22 12.94 0.48Q2 37.40 37.40 1.11Q50 145.63 145.63 Incipient Motion of Sediments 0.00 0.01 3.08 0.05 0.14 1.13 0.0000 0.000 0.04 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.00 0.00 0.00 0.00 0.00 3.0% 4.0% 5.0% 6.0% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 12,240 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 145.63 Lower flow bound for sediment loading (cfs): 37.40 Upper flow bound as a fraction of 50year flow*: 1.11 Lower flow bound as a fraction of 2year flow*: 0.481 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 60.26 Flow depth at effective discharge (ft): 3.94 Shear Stress at effective discharge (lb/ft 0.09 Average flow velocity at effective discharge (ft/s): 1.6 Shear velocity at effective discharge (ft/s): 0.2 Effective width at effective discharge (ft): 18.5 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Very fine gravel Fine sand Medium sand 0.00 0.00 0.00 0.00 0.0% 1.0% 2.0% 1.00 10.00 100.00 1000.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: CCR10 Flow location: CCQ03 Crosssection: CC.1928 Channel Slope: 0.0% Sediment sample: Class 3 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.05 0.05 0.05 0.05 58.65 59.63 2% Q50 131.24 131.2 77.70 161.72 108% Q2 77.70 77.70 131.24 524.04 299% 0.5Q2 38.85 38.85 38.85 80.86 0.08Q2 6.22 6.22 6.22 12.94 0.48Q2 37.40 37.40 1.08Q50 142.20 142.20 Incipient Motion of Sediments 0.01 0.47 25.16 0.12 0.47 1.90 0.0001 0.006 0.32 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.00 0.00 0.00 0.00 0.00 0.00 0.00 3.0% 4.0% 5.0% 6.0% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 3,085 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 142.20 Lower flow bound for sediment loading (cfs): 37.40 Upper flow bound as a fraction of 50year flow*: 1.08 Lower flow bound as a fraction of 2year flow*: 0.481 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 60.26 Flow depth at effective discharge (ft): 2.89 Shear Stress at effective discharge (lb/ft 0.04 Average flow velocity at effective discharge (ft/s): 1.0 Shear velocity at effective discharge (ft/s): 0.1 Effective width at effective discharge (ft): 30.2 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Very coarse sand Fine sand Medium sand 0.00 0.00 0.00 0.00 0.00 0.0% 1.0% 2.0% 1.00 10.00 100.00 1000.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: CCR11 Flow location: CCQ04 Crosssection: CC.2089 Channel Slope: 0.0% Sediment sample: Class 3 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.05 0.05 0.05 0.05 57.21 57.97 1% Q50 104.61 104.6 68.20 127.69 87% Q2 68.20 68.20 104.61 307.84 194% 0.5Q2 34.10 34.10 34.10 63.85 0.08Q2 5.46 5.46 5.46 10.22 0.54Q2 37.06 37.06 1.1Q50 115.55 115.55 Incipient Motion of Sediments 0.02 0.21 61.88 0.20 0.49 4.24 0.0003 0.003 0.91 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.00 0.00 0.00 0.00 0.00 3.0% 4.0% 5.0% 6.0% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 1,396 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 115.55 Lower flow bound for sediment loading (cfs): 37.06 Upper flow bound as a fraction of 50year flow*: 1.10 Lower flow bound as a fraction of 2year flow*: 0.543 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 58.66 Flow depth at effective discharge (ft): 4.14 Shear Stress at effective discharge (lb/ft 0.02 Average flow velocity at effective discharge (ft/s): 0.8 Shear velocity at effective discharge (ft/s): 0.1 Effective width at effective discharge (ft): 35.3 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Very coarse sand Very fine sand Fine sand 0.00 0.00 0.00 0.00 0.0% 1.0% 2.0% 1.00 10.00 100.00 1000.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: CCR12 Flow location: CCQ04 Crosssection: CC.2605 Channel Slope: 0.0% Sediment sample: Class 3 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.05 0.05 0.05 0.05 57.21 57.97 1% Q50 104.61 104.6 68.20 127.69 87% Q2 68.20 68.20 104.61 307.84 194% 0.5Q2 34.10 34.10 34.10 63.85 0.08Q2 5.46 5.46 5.46 10.22 0.54Q2 37.06 37.06 1.1Q50 115.55 115.55 Incipient Motion of Sediments 0.10 0.66 77.63 0.15 0.36 3.50 0.0015 0.010 1.14 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.00 0.00 0.00 0.00 0.00 3.0% 4.0% 5.0% 6.0% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 1,223 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 115.55 Lower flow bound for sediment loading (cfs): 37.06 Upper flow bound as a fraction of 50year flow*: 1.10 Lower flow bound as a fraction of 2year flow*: 0.543 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 58.66 Flow depth at effective discharge (ft): 3.09 Shear Stress at effective discharge (lb/ft 0.02 Average flow velocity at effective discharge (ft/s): 0.8 Shear velocity at effective discharge (ft/s): 0.1 Effective width at effective discharge (ft): 39.3 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Coarse sand Very fine sand Fine sand 0.00 0.00 0.00 0.00 0.0% 1.0% 2.0% 1.00 10.00 100.00 1000.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: CCR13 Flow location: CCQ05 Crosssection: CC.2904 Channel Slope: 0.0% Sediment sample: Class 3 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.03 0.03 0.03 0.03 56.12 56.76 1% Q50 101.03 101.0 68.34 107.41 57% Q2 68.34 68.34 101.03 221.49 119% 0.5Q2 34.17 34.17 34.17 53.71 0.08Q2 5.47 5.47 5.47 8.59 0.54Q2 36.79 36.79 0.97Q50 97.91 97.91 Incipient Motion of Sediments 0.02 0.25 39.68 0.11 0.25 2.11 0.0004 0.004 0.58 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.00 0.00 0.00 0.00 1.5% 2.0% 2.5% 3.0% 3.5% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 2,712 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 97.91 Lower flow bound for sediment loading (cfs): 36.79 Upper flow bound as a fraction of 50year flow*: 0.97 Lower flow bound as a fraction of 2year flow*: 0.538 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 59.29 Flow depth at effective discharge (ft): 2.46 Shear Stress at effective discharge (lb/ft 0.03 Average flow velocity at effective discharge (ft/s): 0.9 Shear velocity at effective discharge (ft/s): 0.1 Effective width at effective discharge (ft): 50.1 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Very coarse sand Fine sand Medium sand 0.00 0.00 0.00 0.0% 0.5% 1.0% 1.5% 1.00 10.00 100.00 1000.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: CCR14 Flow location: CCQ06 Crosssection: CC.3206 Channel Slope: 0.1% Sediment sample: Class 3 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.02 0.02 0.02 0.02 54.16 54.44 1% Q50 87.97 88.0 63.68 64.19 1% Q2 63.68 63.68 87.97 113.98 30% 0.5Q2 31.84 31.84 31.84 32.10 0.08Q2 5.09 5.09 5.09 5.14 0.56Q2 35.51 35.51 0.94Q50 82.79 82.79 Incipient Motion of Sediments 0.01 0.09 23.84 0.07 0.18 1.54 0.0001 0.001 0.37 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.00 0.00 0.00 0.00 0.00 1.0% 1.5% 2.0% 2.5% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 4,351 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 82.79 Lower flow bound for sediment loading (cfs): 35.51 Upper flow bound as a fraction of 50year flow*: 0.94 Lower flow bound as a fraction of 2year flow*: 0.558 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 56.57 Flow depth at effective discharge (ft): 2.10 Shear Stress at effective discharge (lb/ft 0.03 Average flow velocity at effective discharge (ft/s): 0.9 Shear velocity at effective discharge (ft/s): 0.1 Effective width at effective discharge (ft): 54.2 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Very coarse sand Fine sand Medium sand 0.00 0.00 0.00 0.00 0.0% 0.5% 1.0% 1.00 10.00 100.00 1000.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: CCR15 Flow location: CCQ07 Crosssection: BC06 Channel Slope: 0.0% Sediment sample: Class 3 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.04 0.04 0.04 0.04 13.01 13.23 2% Q50 27.17 27.2 17.02 30.25 78% Q2 17.02 17.02 27.17 81.36 199% 0.5Q2 8.51 8.51 8.51 15.12 0.08Q2 1.36 1.36 1.36 2.42 0.54Q2 9.14 9.14 0.95Q50 25.73 25.73 Incipient Motion of Sediments 0.38 5.86 357.67 0.40 0.99 5.07 0.0225 0.344 21.02 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.00 0.00 0.00 0.00 0.00 2.0% 2.5% 3.0% 3.5% 4.0% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 15 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 25.73 Lower flow bound for sediment loading (cfs): 9.14 Upper flow bound as a fraction of 50year flow*: 0.95 Lower flow bound as a fraction of 2year flow*: 0.537 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 13.68 Flow depth at effective discharge (ft): 1.34 Shear Stress at effective discharge (lb/ft 0.00 Average flow velocity at effective discharge (ft/s): 0.3 Shear velocity at effective discharge (ft/s): 0.0 Effective width at effective discharge (ft): 59.6 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Fine sand Very fine sand Fine sand 0.00 0.00 0.00 0.00 0.0% 0.5% 1.0% 1.5% 1.00 10.00 100.00 1000.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: CCR16 Flow location: CCQ07 Crosssection: BC06 Channel Slope: 0.1% Sediment sample: Class 3 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.04 0.04 0.04 0.04 13.01 13.23 2% Q50 27.17 27.2 17.02 30.25 78% Q2 17.02 17.02 27.17 81.36 199% 0.5Q2 8.51 8.51 8.51 15.12 0.08Q2 1.36 1.36 1.36 2.42 0.5Q2 8.54 8.54 0.86Q50 23.42 23.42 Incipient Motion of Sediments 0.00 0.02 9.99 0.04 0.09 0.81 0.0001 0.001 0.59 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.00 0.00 0.00 0.00 0.00 0.00 2.0% 2.5% 3.0% 3.5% 4.0% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 1,915 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 23.42 Lower flow bound for sediment loading (cfs): 8.54 Upper flow bound as a fraction of 50year flow*: 0.86 Lower flow bound as a fraction of 2year flow*: 0.502 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 13.68 Flow depth at effective discharge (ft): 0.90 Shear Stress at effective discharge (lb/ft 0.03 Average flow velocity at effective discharge (ft/s): 0.7 Shear velocity at effective discharge (ft/s): 0.1 Effective width at effective discharge (ft): 47.1 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Very coarse sand Fine sand Medium sand 0.00 0.00 0.00 0.00 0.00 0.0% 0.5% 1.0% 1.5% 1.00 10.00 100.00 1000.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: CCR16 Flow location: CCQ07 Crosssection: BC06 Channel Slope: 0.1% Sediment sample: Class 3 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.04 0.04 0.04 0.04 13.01 13.23 2% Q50 27.17 27.2 17.02 30.25 78% Q2 17.02 17.02 27.17 81.36 199% 0.5Q2 8.51 8.51 8.51 15.12 0.08Q2 1.36 1.36 1.36 2.42 0.5Q2 8.54 8.54 0.86Q50 23.42 23.42 Incipient Motion of Sediments 0.00 0.02 9.99 0.04 0.09 0.81 0.0001 0.001 0.59 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.00 0.00 0.00 0.00 0.00 0.00 2.0% 2.5% 3.0% 3.5% 4.0% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 1,915 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 23.42 Lower flow bound for sediment loading (cfs): 8.54 Upper flow bound as a fraction of 50year flow*: 0.86 Lower flow bound as a fraction of 2year flow*: 0.502 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 13.68 Flow depth at effective discharge (ft): 0.90 Shear Stress at effective discharge (lb/ft 0.03 Average flow velocity at effective discharge (ft/s): 0.7 Shear velocity at effective discharge (ft/s): 0.1 Effective width at effective discharge (ft): 47.1 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Very coarse sand Fine sand Medium sand 0.00 0.00 0.00 0.00 0.00 0.0% 0.5% 1.0% 1.5% 1.00 10.00 100.00 1000.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: CCR18 Flow location: CCQ08 Crosssection: XS415 Channel Slope: 3.7% Sediment sample: Class 2 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.04 0.04 0.04 0.04 3.79 3.91 3% Q50 15.67 15.7 6.55 22.31 241% Q2 6.55 6.55 15.67 74.06 373% 0.5Q2 3.28 3.28 3.28 11.16 0.08Q2 0.52 0.52 0.52 1.78 0.37Q2 2.42 2.42 1.13Q50 17.66 17.66 Incipient Motion of Sediments 0.00 0.39 5.32 0.01 0.10 0.24 0.0001 0.060 0.81 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.02 0.02 0.03 0.03 2.0% 2.5% 3.0% 3.5% 4.0% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 35,830 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 17.66 Lower flow bound for sediment loading (cfs): 2.42 Upper flow bound as a fraction of 50year flow*: 1.13 Lower flow bound as a fraction of 2year flow*: 0.370 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 3.98 Flow depth at effective discharge (ft): 0.22 Shear Stress at effective discharge (lb/ft 0.24 Average flow velocity at effective discharge (ft/s): 1.3 Shear velocity at effective discharge (ft/s): 0.4 Effective width at effective discharge (ft): 29.4 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Fine gravel Medium sand Coarse sand 0.00 0.01 0.01 0.0% 0.5% 1.0% 1.5% 0.10 1.00 10.00 100.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: CCR19 Flow location: CCQ09 Crosssection: XS399 Channel Slope: 5.0% Sediment sample: Class 2 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.02 0.02 0.02 0.02 0.33 0.38 16% Q50 7.58 7.6 1.88 17.21 816% Q2 1.88 1.88 7.58 60.24 694% 0.5Q2 0.94 0.94 0.94 8.60 0.08Q2 0.15 0.15 0.15 1.38 0.11Q2 0.21 0.21 2.62Q50 19.85 19.85 Incipient Motion of Sediments 0.00 0.05 0.63 0.01 0.07 0.17 0.0000 0.026 0.33 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.08 0.10 0.12 0.14 0.16 0.18 1.0% 1.5% 2.0% 2.5% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 14,410 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 19.85 Lower flow bound for sediment loading (cfs): 0.21 Upper flow bound as a fraction of 50year flow*: 2.62 Lower flow bound as a fraction of 2year flow*: 0.113 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 2.17 Flow depth at effective discharge (ft): 0.27 Shear Stress at effective discharge (lb/ft 0.52 Average flow velocity at effective discharge (ft/s): 1.8 Shear velocity at effective discharge (ft/s): 0.5 Effective width at effective discharge (ft): 7.1 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Coarse gravel Coarse sand Very coarse sand 0.00 0.02 0.04 0.06 0.08 0.0% 0.5% 1.0% 0.00 0.01 0.10 1.00 10.00 100.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: CCR20 Flow location: CCQ09 Crosssection: XS399 Channel Slope: 5.2% Sediment sample: Class 1 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.03 0.03 0.03 0.03 0.33 0.38 16% Q50 7.58 7.6 1.88 17.21 816% Q2 1.88 1.88 7.58 60.24 694% 0.5Q2 0.94 0.94 0.94 8.60 0.08Q2 0.15 0.15 0.15 1.38 0.28Q2 0.53 0.53 3.1Q50 23.53 23.53 Incipient Motion of Sediments 0.00 0.30 1.18 0.01 0.13 0.21 0.0001 0.159 0.63 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.08 0.10 0.12 0.14 0.16 0.18 1.5% 2.0% 2.5% 3.0% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 9,393 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 23.53 Lower flow bound for sediment loading (cfs): 0.53 Upper flow bound as a fraction of 50year flow*: 3.10 Lower flow bound as a fraction of 2year flow*: 0.280 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 3.42 Flow depth at effective discharge (ft): 0.32 Shear Stress at effective discharge (lb/ft 0.67 Average flow velocity at effective discharge (ft/s): 2.2 Shear velocity at effective discharge (ft/s): 0.6 Effective width at effective discharge (ft): 7.6 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Coarse gravel Very coarse sand Very fine gravel 0.00 0.02 0.04 0.06 0.08 0.0% 0.5% 1.0% 0.00 0.01 0.10 1.00 10.00 100.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: CCR21 Flow location: CCQ09 Crosssection: XS411 Channel Slope: 11.5% Sediment sample: Class 1 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.02 0.02 0.02 0.02 0.33 0.38 16% Q50 7.58 7.6 1.88 17.21 816% Q2 1.88 1.88 7.58 60.24 694% 0.5Q2 0.94 0.94 0.94 8.60 0.08Q2 0.15 0.15 0.15 1.38 0.07Q2 0.14 0.14 2.47Q50 18.75 18.75 Incipient Motion of Sediments 0.00 0.01 0.03 0.00 0.08 0.16 0.0000 0.003 0.02 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.60 0.80 1.00 1.20 1.0% 1.5% 2.0% 2.5% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 81,496 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 18.75 Lower flow bound for sediment loading (cfs): 0.14 Upper flow bound as a fraction of 50year flow*: 2.47 Lower flow bound as a fraction of 2year flow*: 0.072 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 2.17 Flow depth at effective discharge (ft): 0.77 Shear Stress at effective discharge (lb/ft 1.90 Average flow velocity at effective discharge (ft/s): 3.8 Shear velocity at effective discharge (ft/s): 1.0 Effective width at effective discharge (ft): 2.1 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Very coarse gravel Very fine gravel Fine gravel 0.00 0.20 0.40 0.0% 0.5% 1.0% 0.00 0.01 0.10 1.00 10.00 100.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: CCR22 Flow location: CCQ09 Crosssection: BC07 Channel Slope: 6.4% Sediment sample: Class 1 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.03 0.03 0.03 0.03 0.33 0.38 16% Q50 7.58 7.6 1.88 17.21 816% Q2 1.88 1.88 7.58 60.24 694% 0.5Q2 0.94 0.94 0.94 8.60 0.08Q2 0.15 0.15 0.15 1.38 0.08Q2 0.15 0.15 2.47Q50 18.75 18.75 Incipient Motion of Sediments 0.00 0.02 0.13 0.01 0.14 0.26 0.0000 0.012 0.07 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.10 0.15 0.20 0.25 1.5% 2.0% 2.5% 3.0% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 23,867 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 18.75 Lower flow bound for sediment loading (cfs): 0.15 Upper flow bound as a fraction of 50year flow*: 2.47 Lower flow bound as a fraction of 2year flow*: 0.081 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 2.17 Flow depth at effective discharge (ft): 0.75 Shear Stress at effective discharge (lb/ft 1.12 Average flow velocity at effective discharge (ft/s): 3.4 Shear velocity at effective discharge (ft/s): 0.8 Effective width at effective discharge (ft): 2.3 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Very coarse gravel Very coarse sand Very fine gravel 0.00 0.05 0.10 0.0% 0.5% 1.0% 0.00 0.01 0.10 1.00 10.00 100.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: CCR23 Flow location: CCQ09 Crosssection: BC07 Channel Slope: 0.1% Sediment sample: Class 3 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.02 0.02 0.02 0.02 0.33 0.38 16% Q50 7.58 7.6 1.88 17.21 816% Q2 1.88 1.88 7.58 60.24 694% 0.5Q2 0.94 0.94 0.94 8.60 0.08Q2 0.15 0.15 0.15 1.38 0.05Q2 0.10 0.10 2.62Q50 19.85 19.85 Incipient Motion of Sediments 0.00 0.00 2.41 0.04 0.10 1.18 0.0001 0.001 1.28 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.00 0.00 0.00 0.00 0.00 1.0% 1.5% 2.0% 2.5% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 98 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 19.85 Lower flow bound for sediment loading (cfs): 0.10 Upper flow bound as a fraction of 50year flow*: 2.62 Lower flow bound as a fraction of 2year flow*: 0.054 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 2.17 Flow depth at effective discharge (ft): 1.15 Shear Stress at effective discharge (lb/ft 0.02 Average flow velocity at effective discharge (ft/s): 0.6 Shear velocity at effective discharge (ft/s): 0.1 Effective width at effective discharge (ft): 13.3 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Very coarse sand Very fine sand Fine sand 0.00 0.00 0.00 0.00 0.0% 0.5% 1.0% 0.00 0.01 0.10 1.00 10.00 100.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: CCR24 Flow location: CCQ10 Crosssection: BC07 Channel Slope: 7.4% Sediment sample: Class 1 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.03 0.03 0.03 0.03 0.19 0.23 16% Q50 4.46 4.5 1.10 10.12 816% Q2 1.10 1.10 4.46 35.44 694% 0.5Q2 0.55 0.55 0.55 5.06 0.08Q2 0.09 0.09 0.09 0.81 0.09Q2 0.10 0.10 2.21Q50 9.88 9.88 Incipient Motion of Sediments 0.00 0.02 0.10 0.01 0.12 0.23 0.0000 0.016 0.09 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.06 0.08 0.10 0.12 0.14 1.5% 2.0% 2.5% 3.0% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 16,547 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 9.88 Lower flow bound for sediment loading (cfs): 0.10 Upper flow bound as a fraction of 50year flow*: 2.21 Lower flow bound as a fraction of 2year flow*: 0.090 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 1.28 Flow depth at effective discharge (ft): 0.59 Shear Stress at effective discharge (lb/ft 1.01 Average flow velocity at effective discharge (ft/s): 3.2 Shear velocity at effective discharge (ft/s): 0.7 Effective width at effective discharge (ft): 1.8 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Very coarse gravel Very coarse sand Very fine gravel 0.00 0.02 0.04 0.06 0.0% 0.5% 1.0% 0.00 0.00 0.01 0.10 1.00 10.00 100.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: CCR25 Flow location: CCQ10 Crosssection: BC07 Channel Slope: 1.5% Sediment sample: Class 2 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.04 0.04 0.04 0.04 0.19 0.23 16% Q50 4.46 4.5 1.10 10.12 816% Q2 1.10 1.10 4.46 35.44 694% 0.5Q2 0.55 0.55 0.55 5.06 0.08Q2 0.09 0.09 0.09 0.81 0.15Q2 0.17 0.17 2.94Q50 13.12 13.12 Incipient Motion of Sediments 0.00 0.09 1.18 0.03 0.29 0.77 0.0001 0.079 1.07 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.01 0.01 0.01 0.01 0.01 2.0% 2.5% 3.0% 3.5% 4.0% 4.5% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 760 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 13.12 Lower flow bound for sediment loading (cfs): 0.17 Upper flow bound as a fraction of 50year flow*: 2.94 Lower flow bound as a fraction of 2year flow*: 0.151 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 1.08 Flow depth at effective discharge (ft): 0.74 Shear Stress at effective discharge (lb/ft 0.26 Average flow velocity at effective discharge (ft/s): 1.7 Shear velocity at effective discharge (ft/s): 0.4 Effective width at effective discharge (ft): 2.3 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Medium gravel Medium sand Coarse sand 0.00 0.00 0.00 0.01 0.0% 0.5% 1.0% 1.5% 2.0% 0.00 0.00 0.01 0.10 1.00 10.00 100.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: DCR01 Flow location: DCQ01 Crosssection: XS421 Channel Slope: 0.1% Sediment sample: Class 3 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.02 0.02 0.02 0.02 1.47 1.61 9% Q50 16.56 16.6 2.82 30.01 963% Q2 2.82 2.82 16.56 115.08 595% 0.5Q2 1.41 1.41 1.41 15.01 0.08Q2 0.23 0.23 0.23 2.40 0.26Q2 0.72 0.72 1.8Q50 29.74 29.74 Incipient Motion of Sediments 0.00 0.03 2.59 0.03 0.07 0.42 0.0010 0.012 0.92 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.00 0.00 0.00 0.00 1.5% 2.0% 2.5% 3.0% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 358 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 29.74 Lower flow bound for sediment loading (cfs): 0.72 Upper flow bound as a fraction of 50year flow*: 1.80 Lower flow bound as a fraction of 2year flow*: 0.256 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 2.93 Flow depth at effective discharge (ft): 0.45 Shear Stress at effective discharge (lb/ft 0.03 Average flow velocity at effective discharge (ft/s): 0.8 Shear velocity at effective discharge (ft/s): 0.1 Effective width at effective discharge (ft): 10.6 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Very coarse sand Very fine sand Fine sand 0.00 0.00 0.00 0.0% 0.5% 1.0% 0.10 1.00 10.00 100.00 1000.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: DCR02 Flow location: DCQ01 Crosssection: XS421 Channel Slope: 0.8% Sediment sample: Class 2 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.02 0.02 0.02 0.02 1.47 1.61 9% Q50 16.56 16.6 2.82 30.01 963% Q2 2.82 2.82 16.56 115.08 595% 0.5Q2 1.41 1.41 1.41 15.01 0.08Q2 0.23 0.23 0.23 2.40 1.13Q2 3.20 3.20 3.16Q50 52.31 52.31 Incipient Motion of Sediments 0.01 2.70 21.06 0.03 0.27 0.75 0.0036 0.958 7.46 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.01 0.01 0.01 0.01 0.02 0.02 0.02 1.5% 2.0% 2.5% 3.0% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 710 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 52.31 Lower flow bound for sediment loading (cfs): 3.20 Upper flow bound as a fraction of 50year flow*: 3.16 Lower flow bound as a fraction of 2year flow*: 1.134 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 10.20 Flow depth at effective discharge (ft): 0.51 Shear Stress at effective discharge (lb/ft 0.20 Average flow velocity at effective discharge (ft/s): 2.4 Shear velocity at effective discharge (ft/s): 0.3 Effective width at effective discharge (ft): 11.0 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Fine gravel Medium sand Coarse sand 0.00 0.00 0.00 0.01 0.01 0.0% 0.5% 1.0% 0.10 1.00 10.00 100.00 1000.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: DCR03 Flow location: DCQ02 Crosssection: XS422 Channel Slope: 4.7% Sediment sample: Class 2 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.02 0.02 0.02 0.02 1.24 1.35 9% Q50 13.13 13.1 3.26 28.30 768% Q2 3.26 3.26 13.13 95.22 625% 0.5Q2 1.63 1.63 1.63 14.15 0.08Q2 0.26 0.26 0.26 2.26 0.19Q2 0.63 0.63 2.06Q50 27.09 27.09 Incipient Motion of Sediments 0.00 0.02 0.46 0.01 0.07 0.21 0.0000 0.007 0.14 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.15 0.20 0.25 0.30 1.0% 1.5% 2.0% 2.5% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 46,749 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 27.09 Lower flow bound for sediment loading (cfs): 0.63 Upper flow bound as a fraction of 50year flow*: 2.06 Lower flow bound as a fraction of 2year flow*: 0.193 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 2.48 Flow depth at effective discharge (ft): 0.37 Shear Stress at effective discharge (lb/ft 0.50 Average flow velocity at effective discharge (ft/s): 2.3 Shear velocity at effective discharge (ft/s): 0.5 Effective width at effective discharge (ft): 6.1 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Coarse gravel Coarse sand Very coarse sand 0.00 0.05 0.10 0.0% 0.5% 1.0% 0.10 1.00 10.00 100.00 1000.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: DCR04 Flow location: DCQ02 Crosssection: XS423 Channel Slope: 4.7% Sediment sample: Class 2 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.02 0.02 0.02 0.02 1.24 1.35 9% Q50 13.13 13.1 3.26 28.30 768% Q2 3.26 3.26 13.13 95.22 625% 0.5Q2 1.63 1.63 1.63 14.15 0.08Q2 0.26 0.26 0.26 2.26 0.2Q2 0.67 0.67 2.06Q50 27.09 27.09 Incipient Motion of Sediments 0.00 0.06 0.85 0.01 0.10 0.21 0.0000 0.020 0.26 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.08 0.10 0.12 0.14 0.16 1.0% 1.5% 2.0% 2.5% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 41,579 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 27.09 Lower flow bound for sediment loading (cfs): 0.67 Upper flow bound as a fraction of 50year flow*: 2.06 Lower flow bound as a fraction of 2year flow*: 0.205 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 2.48 Flow depth at effective discharge (ft): 0.29 Shear Stress at effective discharge (lb/ft 0.46 Average flow velocity at effective discharge (ft/s): 1.9 Shear velocity at effective discharge (ft/s): 0.5 Effective width at effective discharge (ft): 8.2 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Medium gravel Coarse sand Very coarse sand 0.00 0.02 0.04 0.06 0.0% 0.5% 1.0% 0.10 1.00 10.00 100.00 1000.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: DCR05 Flow location: DCQ02 Crosssection: XS430 Channel Slope: 8.0% Sediment sample: Class 1 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.02 0.02 0.02 0.02 1.24 1.35 9% Q50 13.13 13.1 3.26 28.30 768% Q2 3.26 3.26 13.13 95.22 625% 0.5Q2 1.63 1.63 1.63 14.15 0.08Q2 0.26 0.26 0.26 2.26 0.2Q2 0.67 0.67 2.19Q50 28.72 28.72 Incipient Motion of Sediments 0.00 0.10 0.57 0.00 0.10 0.18 0.0000 0.031 0.17 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.20 0.25 0.30 0.35 0.40 0.45 1.0% 1.5% 2.0% 2.5% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 74,343 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 28.72 Lower flow bound for sediment loading (cfs): 0.67 Upper flow bound as a fraction of 50year flow*: 2.19 Lower flow bound as a fraction of 2year flow*: 0.205 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 2.48 Flow depth at effective discharge (ft): 0.29 Shear Stress at effective discharge (lb/ft 0.68 Average flow velocity at effective discharge (ft/s): 2.0 Shear velocity at effective discharge (ft/s): 0.6 Effective width at effective discharge (ft): 8.9 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Coarse gravel Very coarse sand Very fine gravel 0.00 0.05 0.10 0.15 0.20 0.0% 0.5% 1.0% 0.10 1.00 10.00 100.00 1000.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: DCR06 Flow location: DCQ03 Crosssection: XS437 Channel Slope: 7.4% Sediment sample: Class 1 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.02 0.02 0.02 0.02 0.52 0.61 19% Q50 10.22 10.2 2.50 23.18 827% Q2 2.50 2.50 10.22 79.53 678% 0.5Q2 1.25 1.25 1.25 11.59 0.08Q2 0.20 0.20 0.20 1.85 0.11Q2 0.29 0.29 2.61Q50 26.66 26.66 Incipient Motion of Sediments 0.00 0.06 0.36 0.00 0.09 0.17 0.0000 0.026 0.14 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.20 0.25 0.30 0.35 0.40 0.45 0.50 1.0% 1.5% 2.0% 2.5% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 41,432 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 26.66 Lower flow bound for sediment loading (cfs): 0.29 Upper flow bound as a fraction of 50year flow*: 2.61 Lower flow bound as a fraction of 2year flow*: 0.115 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 3.70 Flow depth at effective discharge (ft): 0.40 Shear Stress at effective discharge (lb/ft 0.95 Average flow velocity at effective discharge (ft/s): 2.6 Shear velocity at effective discharge (ft/s): 0.7 Effective width at effective discharge (ft): 6.9 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Coarse gravel Very coarse sand Very fine gravel 0.00 0.05 0.10 0.15 0.20 0.0% 0.5% 1.0% 0.00 0.01 0.10 1.00 10.00 100.00 1000.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: DCR07 Flow location: DCQ03 Crosssection: XS440 Channel Slope: 5.0% Sediment sample: Class 2 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.03 0.03 0.03 0.03 0.52 0.61 19% Q50 10.22 10.2 2.50 23.18 827% Q2 2.50 2.50 10.22 79.53 678% 0.5Q2 1.25 1.25 1.25 11.59 0.08Q2 0.20 0.20 0.20 1.85 0.18Q2 0.46 0.46 2.76Q50 28.25 28.25 Incipient Motion of Sediments 0.00 0.20 1.21 0.01 0.07 0.13 0.0001 0.080 0.48 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.08 0.10 0.12 0.14 0.16 0.18 0.20 1.5% 2.0% 2.5% 3.0% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 18,357 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 28.25 Lower flow bound for sediment loading (cfs): 0.46 Upper flow bound as a fraction of 50year flow*: 2.76 Lower flow bound as a fraction of 2year flow*: 0.183 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 3.70 Flow depth at effective discharge (ft): 0.21 Shear Stress at effective discharge (lb/ft 0.48 Average flow velocity at effective discharge (ft/s): 1.8 Shear velocity at effective discharge (ft/s): 0.5 Effective width at effective discharge (ft): 13.3 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Medium gravel Coarse sand Very coarse sand 0.00 0.02 0.04 0.06 0.08 0.0% 0.5% 1.0% 0.00 0.01 0.10 1.00 10.00 100.00 1000.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: DCR08 Flow location: DCQ03 Crosssection: XS440 Channel Slope: 1.9% Sediment sample: Class 2 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.03 0.03 0.03 0.03 0.52 0.61 19% Q50 10.22 10.2 2.50 23.18 827% Q2 2.50 2.50 10.22 79.53 678% 0.5Q2 1.25 1.25 1.25 11.59 0.08Q2 0.20 0.20 0.20 1.85 0.46Q2 1.16 1.16 3.29Q50 33.63 33.63 Incipient Motion of Sediments 0.00 0.89 5.55 0.02 0.13 0.30 0.0012 0.357 2.22 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.02 0.03 0.03 0.04 0.04 0.05 1.5% 2.0% 2.5% 3.0% 3.5% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 2,127 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 33.63 Lower flow bound for sediment loading (cfs): 1.16 Upper flow bound as a fraction of 50year flow*: 3.29 Lower flow bound as a fraction of 2year flow*: 0.463 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 5.25 Flow depth at effective discharge (ft): 0.29 Shear Stress at effective discharge (lb/ft 0.26 Average flow velocity at effective discharge (ft/s): 1.6 Shear velocity at effective discharge (ft/s): 0.4 Effective width at effective discharge (ft): 14.3 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Medium gravel Medium sand Coarse sand 0.00 0.01 0.01 0.02 0.02 0.0% 0.5% 1.0% 1.5% 0.00 0.01 0.10 1.00 10.00 100.00 1000.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: DCR09 Flow location: DCQ04 Crosssection: XS440 Channel Slope: 2.0% Sediment sample: Class 2 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.03 0.03 0.03 0.03 0.37 0.44 19% Q50 7.30 7.3 1.79 16.56 827% Q2 1.79 1.79 7.30 56.81 678% 0.5Q2 0.89 0.89 0.89 8.28 0.08Q2 0.14 0.14 0.14 1.32 0.58Q2 1.04 1.04 3.89Q50 28.42 28.42 Incipient Motion of Sediments 0.00 0.83 5.19 0.01 0.12 0.29 0.0015 0.464 2.91 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.02 0.02 0.03 0.03 0.04 1.5% 2.0% 2.5% 3.0% 3.5% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 1,188 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 28.42 Lower flow bound for sediment loading (cfs): 1.04 Upper flow bound as a fraction of 50year flow*: 3.89 Lower flow bound as a fraction of 2year flow*: 0.581 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 3.72 Flow depth at effective discharge (ft): 0.24 Shear Stress at effective discharge (lb/ft 0.22 Average flow velocity at effective discharge (ft/s): 1.5 Shear velocity at effective discharge (ft/s): 0.3 Effective width at effective discharge (ft): 13.9 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Fine gravel Medium sand Coarse sand 0.00 0.01 0.01 0.02 0.0% 0.5% 1.0% 1.5% 0.00 0.00 0.01 0.10 1.00 10.00 100.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: DCR10 Flow location: DCQ04 Crosssection: XS440 Channel Slope: 1.0% Sediment sample: Class 2 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.04 0.04 0.04 0.04 0.37 0.44 19% Q50 7.30 7.3 1.79 16.56 827% Q2 1.79 1.79 7.30 56.81 678% 0.5Q2 0.89 0.89 0.89 8.28 0.08Q2 0.14 0.14 0.14 1.32 1.24Q2 2.21 2.21 8.28Q50 60.46 60.46 Incipient Motion of Sediments 0.01 1.89 10.96 0.03 0.21 0.50 0.0055 1.057 6.13 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.01 0.01 0.01 0.01 2.0% 2.5% 3.0% 3.5% 4.0% 4.5% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 211 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 60.46 Lower flow bound for sediment loading (cfs): 2.21 Upper flow bound as a fraction of 50year flow*: 8.28 Lower flow bound as a fraction of 2year flow*: 1.236 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 7.48 Flow depth at effective discharge (ft): 0.41 Shear Stress at effective discharge (lb/ft 0.22 Average flow velocity at effective discharge (ft/s): 1.5 Shear velocity at effective discharge (ft/s): 0.3 Effective width at effective discharge (ft): 14.8 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Fine gravel Medium sand Coarse sand 0.00 0.00 0.00 0.0% 0.5% 1.0% 1.5% 2.0% 0.00 0.00 0.01 0.10 1.00 10.00 100.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: MCR01 Flow location: MCQ01 Crosssection: MC.1296 Channel Slope: 0.2% Sediment sample: Class 3 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.02 0.02 0.02 0.02 2.13 1.49 30% Q50 32.58 32.6 8.19 55.95 583% Q2 8.19 8.19 32.58 175.77 439% 0.5Q2 4.09 4.09 4.09 27.97 0.08Q2 0.66 0.66 0.66 4.48 0.06Q2 0.53 0.53 2.06Q50 67.14 67.14 Incipient Motion of Sediments 0.00 0.00 0.39 0.02 0.04 0.35 0.0000 0.000 0.05 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.00 0.00 0.00 0.00 0.8% 1.0% 1.2% 1.4% 1.6% 1.8% 2.0% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 1,808 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 67.14 Lower flow bound for sediment loading (cfs): 0.53 Upper flow bound as a fraction of 50year flow*: 2.06 Lower flow bound as a fraction of 2year flow*: 0.064 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 11.15 Flow depth at effective discharge (ft): 1.55 Shear Stress at effective discharge (lb/ft 0.14 Average flow velocity at effective discharge (ft/s): 1.3 Shear velocity at effective discharge (ft/s): 0.3 Effective width at effective discharge (ft): 8.5 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Fine gravel Medium sand Coarse sand 0.00 0.00 0.00 0.0% 0.2% 0.4% 0.6% 0.8% 0.01 0.10 1.00 10.00 100.00 1000.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: MCR02 Flow location: MCQ02 Crosssection: MC.3860 Channel Slope: 0.1% Sediment sample: Class 3 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.02 0.02 0.02 0.02 1.44 1.01 30% Q50 22.00 22.0 5.53 37.78 583% Q2 5.53 5.53 22.00 118.71 439% 0.5Q2 2.77 2.77 2.77 18.89 0.08Q2 0.44 0.44 0.44 3.02 0.07Q2 0.37 0.37 2.36Q50 51.90 51.90 Incipient Motion of Sediments 0.00 0.01 0.96 0.03 0.07 0.51 0.0001 0.001 0.17 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.00 0.00 0.00 0.00 0.00 0.00 0.8% 1.0% 1.2% 1.4% 1.6% 1.8% 2.0% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 513 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 51.90 Lower flow bound for sediment loading (cfs): 0.37 Upper flow bound as a fraction of 50year flow*: 2.36 Lower flow bound as a fraction of 2year flow*: 0.067 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 7.54 Flow depth at effective discharge (ft): 1.28 Shear Stress at effective discharge (lb/ft 0.07 Average flow velocity at effective discharge (ft/s): 0.9 Shear velocity at effective discharge (ft/s): 0.2 Effective width at effective discharge (ft): 9.8 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Very fine gravel Fine sand Medium sand 0.00 0.00 0.00 0.00 0.00 0.0% 0.2% 0.4% 0.6% 0.8% 0.01 0.10 1.00 10.00 100.00 1000.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: MCR03 Flow location: MCQ03 Crosssection: MC.5962 Channel Slope: 0.2% Sediment sample: Class 3 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.02 0.02 0.02 0.02 0.98 0.46 54% Q50 14.40 14.4 3.60 22.96 538% Q2 3.60 3.60 14.40 93.45 549% 0.5Q2 1.80 1.80 1.80 11.48 0.08Q2 0.29 0.29 0.29 1.84 0.05Q2 0.19 0.19 2.32Q50 33.40 33.40 Incipient Motion of Sediments 0.00 0.00 0.60 0.02 0.04 0.35 0.0001 0.001 0.17 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.00 0.00 0.00 0.00 1.5% 2.0% 2.5% 3.0% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 411 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 33.40 Lower flow bound for sediment loading (cfs): 0.19 Upper flow bound as a fraction of 50year flow*: 2.32 Lower flow bound as a fraction of 2year flow*: 0.052 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 3.99 Flow depth at effective discharge (ft): 0.76 Shear Stress at effective discharge (lb/ft 0.07 Average flow velocity at effective discharge (ft/s): 0.8 Shear velocity at effective discharge (ft/s): 0.2 Effective width at effective discharge (ft): 9.2 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Very fine gravel Fine sand Medium sand 0.00 0.00 0.00 0.0% 0.5% 1.0% 0.00 0.01 0.10 1.00 10.00 100.00 1000.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: MCR04 Flow location: MCQ03 Crosssection: MC.8686 Channel Slope: 0.5% Sediment sample: Class 3 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.02 0.02 0.02 0.02 0.98 0.46 54% Q50 14.40 14.4 3.60 22.96 538% Q2 3.60 3.60 14.40 93.45 549% 0.5Q2 1.80 1.80 1.80 11.48 0.08Q2 0.29 0.29 0.29 1.84 0.05Q2 0.16 0.16 2.19Q50 31.49 31.49 Incipient Motion of Sediments 0.00 0.00 0.05 0.01 0.02 0.18 0.0000 0.000 0.01 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.00 0.01 0.01 0.01 0.01 1.0% 1.5% 2.0% 2.5% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 1,410 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 31.49 Lower flow bound for sediment loading (cfs): 0.16 Upper flow bound as a fraction of 50year flow*: 2.19 Lower flow bound as a fraction of 2year flow*: 0.046 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 3.99 Flow depth at effective discharge (ft): 0.90 Shear Stress at effective discharge (lb/ft 0.15 Average flow velocity at effective discharge (ft/s): 1.2 Shear velocity at effective discharge (ft/s): 0.3 Effective width at effective discharge (ft): 6.2 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Fine gravel Medium sand Coarse sand 0.00 0.00 0.00 0.00 0.0% 0.5% 1.0% 0.00 0.01 0.10 1.00 10.00 100.00 1000.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: MCR05 Flow location: MCQ04 Crosssection: MC.pipe Channel Slope: 0.6% Sediment sample: Class 2 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.05 0.05 0.05 0.05 0.41 0.19 54% Q50 6.00 6.0 1.50 9.57 538% Q2 1.50 1.50 6.00 38.93 549% 0.5Q2 0.75 0.75 0.75 4.78 0.08Q2 0.12 0.12 0.12 0.77 1.19Q2 1.78 1.78 7.61Q50 45.67 45.67 Incipient Motion of Sediments 0.00 1.51 15.17 0.02 0.38 1.21 0.0024 1.009 10.12 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.00 0.01 0.01 0.01 0.01 0.01 2.0% 2.5% 3.0% 3.5% 4.0% 4.5% 5.0% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 42 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 45.67 Lower flow bound for sediment loading (cfs): 1.78 Upper flow bound as a fraction of 50year flow*: 7.61 Lower flow bound as a fraction of 2year flow*: 1.186 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 4.31 Flow depth at effective discharge (ft): 0.63 Shear Stress at effective discharge (lb/ft 0.16 Average flow velocity at effective discharge (ft/s): 3.6 Shear velocity at effective discharge (ft/s): 0.3 Effective width at effective discharge (ft): 2.8 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Fine gravel Medium sand Coarse sand 0.00 0.00 0.00 0.00 0.00 0.0% 0.5% 1.0% 1.5% 2.0% 0.00 0.00 0.01 0.10 1.00 10.00 100.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: RCR01 Flow location: RCQ01 Crosssection: BC02 Channel Slope: 0.1% Sediment sample: Class 3 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.03 0.03 0.03 0.03 1.74 1.89 8% Q50 14.02 14.0 4.59 24.70 438% Q2 4.59 4.59 14.02 91.74 554% 0.5Q2 2.30 2.30 2.30 12.35 0.08Q2 0.37 0.37 0.37 1.98 0.21Q2 0.97 0.97 1.67Q50 23.44 23.44 Incipient Motion of Sediments 0.00 0.01 3.69 0.04 0.11 0.84 0.0003 0.003 0.80 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.00 0.00 0.00 0.00 1.5% 2.0% 2.5% 3.0% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 240 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 23.44 Lower flow bound for sediment loading (cfs): 0.97 Upper flow bound as a fraction of 50year flow*: 1.67 Lower flow bound as a fraction of 2year flow*: 0.212 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 1.98 Flow depth at effective discharge (ft): 0.67 Shear Stress at effective discharge (lb/ft 0.02 Average flow velocity at effective discharge (ft/s): 0.7 Shear velocity at effective discharge (ft/s): 0.1 Effective width at effective discharge (ft): 8.5 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Coarse sand Very fine sand Fine sand 0.00 0.00 0.00 0.0% 0.5% 1.0% 0.10 1.00 10.00 100.00 1000.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: RCR02 Flow location: RCQ01 Crosssection: BC03 Channel Slope: 0.8% Sediment sample: Class 2 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.03 0.03 0.03 0.03 1.74 1.89 8% Q50 14.02 14.0 4.59 24.70 438% Q2 4.59 4.59 14.02 91.74 554% 0.5Q2 2.30 2.30 2.30 12.35 0.08Q2 0.37 0.37 0.37 1.98 0.32Q2 1.48 1.48 2.29Q50 32.13 32.13 Incipient Motion of Sediments 0.01 1.15 12.42 0.04 0.32 0.98 0.0011 0.252 2.71 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.01 0.01 0.01 0.01 0.01 1.5% 2.0% 2.5% 3.0% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 1,385 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 32.13 Lower flow bound for sediment loading (cfs): 1.48 Upper flow bound as a fraction of 50year flow*: 2.29 Lower flow bound as a fraction of 2year flow*: 0.323 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 3.53 Flow depth at effective discharge (ft): 0.55 Shear Stress at effective discharge (lb/ft 0.16 Average flow velocity at effective discharge (ft/s): 2.1 Shear velocity at effective discharge (ft/s): 0.3 Effective width at effective discharge (ft): 4.8 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Fine gravel Medium sand Coarse sand 0.00 0.00 0.00 0.01 0.0% 0.5% 1.0% 0.10 1.00 10.00 100.00 1000.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: RCR03 Flow location: RCQ02 Crosssection: XS473 Channel Slope: 3.6% Sediment sample: Class 2 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.03 0.03 0.03 0.03 0.53 0.64 21% Q50 10.85 10.8 2.70 23.95 786% Q2 2.70 2.70 10.85 77.63 616% 0.5Q2 1.35 1.35 1.35 11.97 0.08Q2 0.22 0.22 0.22 1.92 0.21Q2 0.57 0.57 2.83Q50 30.65 30.65 Incipient Motion of Sediments 0.00 0.28 1.51 0.01 0.09 0.17 0.0002 0.103 0.56 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.03 0.04 0.05 0.06 1.5% 2.0% 2.5% 3.0% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 13,361 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 30.65 Lower flow bound for sediment loading (cfs): 0.57 Upper flow bound as a fraction of 50year flow*: 2.83 Lower flow bound as a fraction of 2year flow*: 0.209 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 4.54 Flow depth at effective discharge (ft): 0.28 Shear Stress at effective discharge (lb/ft 0.49 Average flow velocity at effective discharge (ft/s): 2.4 Shear velocity at effective discharge (ft/s): 0.5 Effective width at effective discharge (ft): 8.6 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Medium gravel Coarse sand Very coarse sand 0.00 0.01 0.02 0.0% 0.5% 1.0% 0.00 0.01 0.10 1.00 10.00 100.00 1000.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: RCR04 Flow location: RCQ02 Crosssection: XS468 Channel Slope: 4.7% Sediment sample: Class 2 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.03 0.03 0.03 0.03 0.53 0.64 21% Q50 10.85 10.8 2.70 23.95 786% Q2 2.70 2.70 10.85 77.63 616% 0.5Q2 1.35 1.35 1.35 11.97 0.08Q2 0.22 0.22 0.22 1.92 0.1Q2 0.27 0.27 2.67Q50 28.93 28.93 Incipient Motion of Sediments 0.00 0.04 0.98 0.01 0.06 0.21 0.0000 0.016 0.36 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.04 0.05 0.06 0.07 0.08 0.09 1.5% 2.0% 2.5% 3.0% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 18,721 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 28.93 Lower flow bound for sediment loading (cfs): 0.27 Upper flow bound as a fraction of 50year flow*: 2.67 Lower flow bound as a fraction of 2year flow*: 0.099 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 2.86 Flow depth at effective discharge (ft): 0.29 Shear Stress at effective discharge (lb/ft 0.40 Average flow velocity at effective discharge (ft/s): 1.7 Shear velocity at effective discharge (ft/s): 0.5 Effective width at effective discharge (ft): 12.0 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Medium gravel Coarse sand Very coarse sand 0.00 0.01 0.02 0.03 0.04 0.0% 0.5% 1.0% 0.00 0.01 0.10 1.00 10.00 100.00 1000.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: RCR05 Flow location: RCQ02 Crosssection: XS468 Channel Slope: 12.4% Sediment sample: Class 1 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.02 0.02 0.02 0.02 0.53 0.64 21% Q50 10.85 10.8 2.70 23.95 786% Q2 2.70 2.70 10.85 77.63 616% 0.5Q2 1.35 1.35 1.35 11.97 0.08Q2 0.22 0.22 0.22 1.92 0.09Q2 0.24 0.24 2.52Q50 27.30 27.30 Incipient Motion of Sediments 0.00 0.03 0.20 0.00 0.04 0.10 0.0000 0.011 0.08 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.15 0.20 0.25 0.30 0.35 1.5% 2.0% 2.5% 3.0% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 79,984 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 27.30 Lower flow bound for sediment loading (cfs): 0.24 Upper flow bound as a fraction of 50year flow*: 2.52 Lower flow bound as a fraction of 2year flow*: 0.088 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 2.86 Flow depth at effective discharge (ft): 0.26 Shear Stress at effective discharge (lb/ft 0.91 Average flow velocity at effective discharge (ft/s): 2.3 Shear velocity at effective discharge (ft/s): 0.7 Effective width at effective discharge (ft): 10.4 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Coarse gravel Very coarse sand Very fine gravel 0.00 0.05 0.10 0.15 0.0% 0.5% 1.0% 0.00 0.01 0.10 1.00 10.00 100.00 1000.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: RCR06 Flow location: RCQ02 Crosssection: BC13 Channel Slope: 4.7% Sediment sample: Class 2 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.02 0.02 0.02 0.02 0.53 0.64 21% Q50 10.85 10.8 2.70 23.95 786% Q2 2.70 2.70 10.85 77.63 616% 0.5Q2 1.35 1.35 1.35 11.97 0.08Q2 0.22 0.22 0.22 1.92 0.1Q2 0.28 0.28 2.67Q50 28.93 28.93 Incipient Motion of Sediments 0.00 0.06 0.75 0.01 0.07 0.18 0.0000 0.020 0.28 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.04 0.05 0.06 0.07 0.08 0.09 0.10 1.5% 2.0% 2.5% 3.0% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 22,317 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 28.93 Lower flow bound for sediment loading (cfs): 0.28 Upper flow bound as a fraction of 50year flow*: 2.67 Lower flow bound as a fraction of 2year flow*: 0.104 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 2.86 Flow depth at effective discharge (ft): 0.30 Shear Stress at effective discharge (lb/ft 0.48 Average flow velocity at effective discharge (ft/s): 1.7 Shear velocity at effective discharge (ft/s): 0.5 Effective width at effective discharge (ft): 9.8 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Medium gravel Coarse sand Very coarse sand 0.00 0.01 0.02 0.03 0.04 0.0% 0.5% 1.0% 0.00 0.01 0.10 1.00 10.00 100.00 1000.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: RCR07 Flow location: RCQ02 Crosssection: XS456 Channel Slope: 5.1% Sediment sample: Class 1 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.03 0.03 0.03 0.03 0.53 0.64 21% Q50 10.85 10.8 2.70 23.95 786% Q2 2.70 2.70 10.85 77.63 616% 0.5Q2 1.35 1.35 1.35 11.97 0.08Q2 0.22 0.22 0.22 1.92 0.14Q2 0.38 0.38 2.99Q50 32.48 32.48 Incipient Motion of Sediments 0.00 0.13 0.74 0.01 0.13 0.25 0.0000 0.050 0.28 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.10 0.15 0.20 0.25 1.5% 2.0% 2.5% 3.0% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 22,300 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 32.48 Lower flow bound for sediment loading (cfs): 0.38 Upper flow bound as a fraction of 50year flow*: 2.99 Lower flow bound as a fraction of 2year flow*: 0.139 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 2.86 Flow depth at effective discharge (ft): 0.41 Shear Stress at effective discharge (lb/ft 0.64 Average flow velocity at effective discharge (ft/s): 2.1 Shear velocity at effective discharge (ft/s): 0.6 Effective width at effective discharge (ft): 6.6 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Coarse gravel Very coarse sand Very fine gravel 0.00 0.05 0.10 0.0% 0.5% 1.0% 0.00 0.01 0.10 1.00 10.00 100.00 1000.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: RCR08 Flow location: RCQ03 Crosssection: XS456 Channel Slope: 7.7% Sediment sample: Class 1 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.02 0.02 0.02 0.02 0.43 0.52 22% Q50 9.34 9.3 2.52 20.08 696% Q2 2.52 2.52 9.34 67.13 619% 0.5Q2 1.26 1.26 1.26 10.04 0.08Q2 0.20 0.20 0.20 1.61 0.1Q2 0.25 0.25 2.72Q50 25.44 25.44 Incipient Motion of Sediments 0.00 0.05 0.30 0.00 0.09 0.16 0.0000 0.022 0.12 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.20 0.25 0.30 0.35 0.40 1.5% 2.0% 2.5% 3.0% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 39,492 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 25.44 Lower flow bound for sediment loading (cfs): 0.25 Upper flow bound as a fraction of 50year flow*: 2.72 Lower flow bound as a fraction of 2year flow*: 0.098 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 2.44 Flow depth at effective discharge (ft): 0.36 Shear Stress at effective discharge (lb/ft 0.85 Average flow velocity at effective discharge (ft/s): 2.4 Shear velocity at effective discharge (ft/s): 0.7 Effective width at effective discharge (ft): 5.7 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Coarse gravel Very coarse sand Very fine gravel 0.00 0.05 0.10 0.15 0.0% 0.5% 1.0% 0.00 0.01 0.10 1.00 10.00 100.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: RCR09 Flow location: RCQ03 Crosssection: XS446 Channel Slope: 3.4% Sediment sample: Class 2 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.03 0.03 0.03 0.03 0.43 0.52 22% Q50 9.34 9.3 2.52 20.08 696% Q2 2.52 2.52 9.34 67.13 619% 0.5Q2 1.26 1.26 1.26 10.04 0.08Q2 0.20 0.20 0.20 1.61 0.17Q2 0.44 0.44 3.05Q50 28.53 28.53 Incipient Motion of Sediments 0.00 0.15 2.11 0.01 0.10 0.24 0.0001 0.061 0.84 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.04 0.05 0.06 0.07 0.08 0.09 0.10 1.5% 2.0% 2.5% 3.0% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 7,995 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 28.53 Lower flow bound for sediment loading (cfs): 0.44 Upper flow bound as a fraction of 50year flow*: 3.05 Lower flow bound as a fraction of 2year flow*: 0.174 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 3.86 Flow depth at effective discharge (ft): 0.29 Shear Stress at effective discharge (lb/ft 0.38 Average flow velocity at effective discharge (ft/s): 1.6 Shear velocity at effective discharge (ft/s): 0.4 Effective width at effective discharge (ft): 13.5 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Medium gravel Coarse sand Very coarse sand 0.00 0.01 0.02 0.03 0.04 0.0% 0.5% 1.0% 0.00 0.01 0.10 1.00 10.00 100.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: RCR10 Flow location: RCQ04 Crosssection: XS446 Channel Slope: 0.9% Sediment sample: Class 2 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.04 0.04 0.04 0.04 0.38 0.46 22% Q50 8.26 8.3 2.23 17.74 696% Q2 2.23 2.23 8.26 59.33 619% 0.5Q2 1.11 1.11 1.11 8.87 0.08Q2 0.18 0.18 0.18 1.42 1.21Q2 2.70 2.70 6.04Q50 49.84 49.84 Incipient Motion of Sediments 0.00 2.35 13.37 0.03 0.30 0.64 0.0022 1.054 6.00 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.00 0.01 0.01 0.01 0.01 0.01 0.01 2.0% 2.5% 3.0% 3.5% 4.0% 4.5% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 198 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 49.84 Lower flow bound for sediment loading (cfs): 2.70 Upper flow bound as a fraction of 50year flow*: 6.04 Lower flow bound as a fraction of 2year flow*: 1.212 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 5.68 Flow depth at effective discharge (ft): 0.43 Shear Stress at effective discharge (lb/ft 0.17 Average flow velocity at effective discharge (ft/s): 1.3 Shear velocity at effective discharge (ft/s): 0.3 Effective width at effective discharge (ft): 14.1 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Fine gravel Medium sand Coarse sand 0.00 0.00 0.00 0.00 0.00 0.0% 0.5% 1.0% 1.5% 2.0% 0.00 0.00 0.01 0.10 1.00 10.00 100.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: SCR01 Flow location: SCQ01 Crosssection: XS487 Channel Slope: 0.0% Sediment sample: Class 3 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.03 0.03 0.03 0.03 0.36 0.45 22% Q50 6.62 6.6 1.73 15.33 785% Q2 1.73 1.73 6.62 57.77 772% 0.5Q2 0.87 0.87 0.87 7.67 0.08Q2 0.14 0.14 0.14 1.23 0.99Q2 1.71 1.71 4.24Q50 28.10 28.10 Incipient Motion of Sediments 0.16 1.40 68.05 0.26 0.74 3.33 0.0943 0.810 39.29 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.00 0.00 0.00 0.00 0.00 1.5% 2.0% 2.5% 3.0% 3.5% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 1 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 28.10 Lower flow bound for sediment loading (cfs): 1.71 Upper flow bound as a fraction of 50year flow*: 4.24 Lower flow bound as a fraction of 2year flow*: 0.989 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 4.62 Flow depth at effective discharge (ft): 1.26 Shear Stress at effective discharge (lb/ft 0.00 Average flow velocity at effective discharge (ft/s): 0.4 Shear velocity at effective discharge (ft/s): 0.0 Effective width at effective discharge (ft): 17.3 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Fine sand Very fine sand Fine sand 0.00 0.00 0.00 0.00 0.0% 0.5% 1.0% 1.5% 0.01 0.10 1.00 10.00 100.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: SCR02 Flow location: SCQ01 Crosssection: XS487 Channel Slope: 2.5% Sediment sample: Class 2 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.02 0.02 0.02 0.02 0.36 0.45 22% Q50 6.62 6.6 1.73 15.33 785% Q2 1.73 1.73 6.62 57.77 772% 0.5Q2 0.87 0.87 0.87 7.67 0.08Q2 0.14 0.14 0.14 1.23 0.35Q2 0.61 0.61 3.71Q50 24.54 24.54 Incipient Motion of Sediments 0.00 0.35 2.12 0.01 0.13 0.25 0.0003 0.200 1.23 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.02 0.03 0.03 0.04 0.04 0.05 1.5% 2.0% 2.5% 3.0% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 4,281 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 24.54 Lower flow bound for sediment loading (cfs): 0.61 Upper flow bound as a fraction of 50year flow*: 3.71 Lower flow bound as a fraction of 2year flow*: 0.350 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 2.81 Flow depth at effective discharge (ft): 0.29 Shear Stress at effective discharge (lb/ft 0.31 Average flow velocity at effective discharge (ft/s): 2.1 Shear velocity at effective discharge (ft/s): 0.4 Effective width at effective discharge (ft): 6.6 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Medium gravel Coarse sand Very coarse sand 0.00 0.01 0.01 0.02 0.02 0.0% 0.5% 1.0% 0.01 0.10 1.00 10.00 100.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: SCR03 Flow location: SCQ01 Crosssection: XS485 Channel Slope: 8.3% Sediment sample: Class 1 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.02 0.02 0.02 0.02 0.36 0.45 22% Q50 6.62 6.6 1.73 15.33 785% Q2 1.73 1.73 6.62 57.77 772% 0.5Q2 0.87 0.87 0.87 7.67 0.08Q2 0.14 0.14 0.14 1.23 0.08Q2 0.14 0.14 3.54Q50 23.46 23.46 Incipient Motion of Sediments 0.00 0.02 0.52 0.01 0.10 0.34 0.0000 0.009 0.30 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.30 0.40 0.50 0.60 1.0% 1.5% 2.0% 2.5% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 30,681 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 23.46 Lower flow bound for sediment loading (cfs): 0.14 Upper flow bound as a fraction of 50year flow*: 3.54 Lower flow bound as a fraction of 2year flow*: 0.079 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 2.81 Flow depth at effective discharge (ft): 0.48 Shear Stress at effective discharge (lb/ft 0.80 Average flow velocity at effective discharge (ft/s): 2.7 Shear velocity at effective discharge (ft/s): 0.6 Effective width at effective discharge (ft): 6.5 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Coarse gravel Very coarse sand Very fine gravel 0.00 0.10 0.20 0.0% 0.5% 1.0% 0.01 0.10 1.00 10.00 100.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: SCR04 Flow location: SCQ03 Crosssection: XS485 Channel Slope: 2.4% Sediment sample: Class 2 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.03 0.03 0.03 0.03 0.27 0.33 22% Q50 4.44 4.4 1.19 14.84 1144% Q2 1.19 1.19 4.44 46.62 949% 0.5Q2 0.60 0.60 0.60 7.42 0.08Q2 0.10 0.10 0.10 1.19 0.32Q2 0.38 0.38 5.04Q50 22.38 22.38 Incipient Motion of Sediments 0.00 0.03 1.84 0.02 0.17 0.52 0.0000 0.026 1.54 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.03 0.04 0.05 0.06 1.5% 2.0% 2.5% 3.0% 3.5% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 3,491 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 22.38 Lower flow bound for sediment loading (cfs): 0.38 Upper flow bound as a fraction of 50year flow*: 5.04 Lower flow bound as a fraction of 2year flow*: 0.316 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 3.24 Flow depth at effective discharge (ft): 0.60 Shear Stress at effective discharge (lb/ft 0.35 Average flow velocity at effective discharge (ft/s): 1.8 Shear velocity at effective discharge (ft/s): 0.4 Effective width at effective discharge (ft): 7.7 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Medium gravel Coarse sand Very coarse sand 0.00 0.01 0.02 0.0% 0.5% 1.0% 1.5% 0.00 0.01 0.10 1.00 10.00 100.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: SCR05 Flow location: SCQ03 Crosssection: XS485 Channel Slope: 3.2% Sediment sample: Class 2 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.03 0.03 0.03 0.03 0.27 0.33 22% Q50 4.44 4.4 1.19 14.84 1144% Q2 1.19 1.19 4.44 46.62 949% 0.5Q2 0.60 0.60 0.60 7.42 0.08Q2 0.10 0.10 0.10 1.19 0.18Q2 0.22 0.22 4.77Q50 21.18 21.18 Incipient Motion of Sediments 0.00 0.02 1.03 0.01 0.13 0.45 0.0000 0.013 0.86 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.04 0.05 0.06 0.07 0.08 0.09 0.10 1.5% 2.0% 2.5% 3.0% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 6,549 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 21.18 Lower flow bound for sediment loading (cfs): 0.22 Upper flow bound as a fraction of 50year flow*: 4.77 Lower flow bound as a fraction of 2year flow*: 0.182 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 3.24 Flow depth at effective discharge (ft): 0.59 Shear Stress at effective discharge (lb/ft 0.46 Average flow velocity at effective discharge (ft/s): 1.8 Shear velocity at effective discharge (ft/s): 0.5 Effective width at effective discharge (ft): 7.7 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Medium gravel Coarse sand Very coarse sand 0.00 0.01 0.02 0.03 0.04 0.0% 0.5% 1.0% 0.00 0.01 0.10 1.00 10.00 100.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: SCR06 Flow location: SCQ03 Crosssection: XS494 Channel Slope: 3.2% Sediment sample: Class 2 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.03 0.03 0.03 0.03 0.27 0.33 22% Q50 4.44 4.4 1.19 14.84 1144% Q2 1.19 1.19 4.44 46.62 949% 0.5Q2 0.60 0.60 0.60 7.42 0.08Q2 0.10 0.10 0.10 1.19 0.2Q2 0.24 0.24 4.51Q50 20.04 20.04 Incipient Motion of Sediments 0.00 0.10 0.53 0.01 0.09 0.19 0.0001 0.080 0.45 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.06 0.08 0.10 0.12 1.5% 2.0% 2.5% 3.0% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 7,456 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 20.04 Lower flow bound for sediment loading (cfs): 0.24 Upper flow bound as a fraction of 50year flow*: 4.51 Lower flow bound as a fraction of 2year flow*: 0.203 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 3.24 Flow depth at effective discharge (ft): 0.43 Shear Stress at effective discharge (lb/ft 0.49 Average flow velocity at effective discharge (ft/s): 1.9 Shear velocity at effective discharge (ft/s): 0.5 Effective width at effective discharge (ft): 6.9 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Medium gravel Coarse sand Very coarse sand 0.00 0.02 0.04 0.0% 0.5% 1.0% 0.00 0.01 0.10 1.00 10.00 100.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: SCR07 Flow location: SCQ03 Crosssection: XS494 Channel Slope: 6.8% Sediment sample: Class 1 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.03 0.03 0.03 0.03 0.27 0.33 22% Q50 4.44 4.4 1.19 14.84 1144% Q2 1.19 1.19 4.44 46.62 949% 0.5Q2 0.60 0.60 0.60 7.42 0.08Q2 0.10 0.10 0.10 1.19 0.24Q2 0.29 0.29 4.51Q50 20.04 20.04 Incipient Motion of Sediments 0.00 0.13 0.40 0.01 0.09 0.14 0.0001 0.109 0.33 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.15 0.20 0.25 0.30 0.35 1.5% 2.0% 2.5% 3.0% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 19,801 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 20.04 Lower flow bound for sediment loading (cfs): 0.29 Upper flow bound as a fraction of 50year flow*: 4.51 Lower flow bound as a fraction of 2year flow*: 0.240 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 1.42 Flow depth at effective discharge (ft): 0.29 Shear Stress at effective discharge (lb/ft 0.52 Average flow velocity at effective discharge (ft/s): 1.7 Shear velocity at effective discharge (ft/s): 0.5 Effective width at effective discharge (ft): 6.5 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Coarse gravel Coarse sand Very coarse sand 0.00 0.05 0.10 0.15 0.0% 0.5% 1.0% 0.00 0.01 0.10 1.00 10.00 100.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: SCR08 Flow location: SCQ03 Crosssection: XS488 Channel Slope: 3.7% Sediment sample: Class 2 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.03 0.03 0.03 0.03 0.27 0.33 22% Q50 4.44 4.4 1.19 14.84 1144% Q2 1.19 1.19 4.44 46.62 949% 0.5Q2 0.60 0.60 0.60 7.42 0.08Q2 0.10 0.10 0.10 1.19 0.18Q2 0.22 0.22 4.27Q50 18.96 18.96 Incipient Motion of Sediments 0.00 0.06 0.74 0.01 0.10 0.25 0.0001 0.048 0.62 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.03 0.04 0.05 0.06 1.5% 2.0% 2.5% 3.0% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 8,284 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 18.96 Lower flow bound for sediment loading (cfs): 0.22 Upper flow bound as a fraction of 50year flow*: 4.27 Lower flow bound as a fraction of 2year flow*: 0.182 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 3.24 Flow depth at effective discharge (ft): 0.42 Shear Stress at effective discharge (lb/ft 0.49 Average flow velocity at effective discharge (ft/s): 2.1 Shear velocity at effective discharge (ft/s): 0.5 Effective width at effective discharge (ft): 6.9 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Medium gravel Coarse sand Very coarse sand 0.00 0.01 0.02 0.0% 0.5% 1.0% 0.00 0.01 0.10 1.00 10.00 100.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: SCR09 Flow location: SCQ04 Crosssection: XS488 Channel Slope: 2.6% Sediment sample: Class 2 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.03 0.03 0.03 0.03 0.20 0.24 22% Q50 3.30 3.3 0.89 11.03 1144% Q2 0.89 0.89 3.30 34.67 949% 0.5Q2 0.44 0.44 0.44 5.52 0.08Q2 0.07 0.07 0.07 0.88 0.28Q2 0.25 0.25 4.74Q50 15.67 15.67 Incipient Motion of Sediments 0.00 0.12 1.59 0.01 0.14 0.35 0.0002 0.139 1.79 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.01 0.02 0.02 0.03 1.5% 2.0% 2.5% 3.0% 3.5% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 2,562 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 15.67 Lower flow bound for sediment loading (cfs): 0.25 Upper flow bound as a fraction of 50year flow*: 4.74 Lower flow bound as a fraction of 2year flow*: 0.282 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 2.40 Flow depth at effective discharge (ft): 0.40 Shear Stress at effective discharge (lb/ft 0.32 Average flow velocity at effective discharge (ft/s): 1.8 Shear velocity at effective discharge (ft/s): 0.4 Effective width at effective discharge (ft): 6.7 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Medium gravel Coarse sand Very coarse sand 0.00 0.01 0.01 0.0% 0.5% 1.0% 1.5% 0.00 0.00 0.01 0.10 1.00 10.00 100.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: UCTR01 Flow location: UCTQ02 Crosssection: XS411 Channel Slope: 8.5% Sediment sample: Class 1 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.02 0.02 0.02 0.02 0.09 0.10 13% Q50 1.63 1.6 0.36 3.45 848% Q2 0.36 0.36 1.63 12.19 646% 0.5Q2 0.18 0.18 0.18 1.73 0.08Q2 0.03 0.03 0.03 0.28 0.13Q2 0.05 0.05 2.48Q50 4.04 4.04 Incipient Motion of Sediments 0.00 0.01 0.06 0.01 0.11 0.22 0.0000 0.031 0.17 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.08 0.10 0.12 0.14 0.16 0.18 0.20 1.0% 1.5% 2.0% 2.5% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 6,923 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 4.04 Lower flow bound for sediment loading (cfs): 0.05 Upper flow bound as a fraction of 50year flow*: 2.48 Lower flow bound as a fraction of 2year flow*: 0.132 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 0.29 Flow depth at effective discharge (ft): 0.38 Shear Stress at effective discharge (lb/ft 0.69 Average flow velocity at effective discharge (ft/s): 2.0 Shear velocity at effective discharge (ft/s): 0.6 Effective width at effective discharge (ft): 1.1 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Coarse gravel Very coarse sand Very fine gravel 0.00 0.02 0.04 0.06 0.08 0.0% 0.5% 1.0% 0.00 0.01 0.10 1.00 10.00 100.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: UMER01 Flow location: UMEQ01 Crosssection: BC11 Channel Slope: 0.4% Sediment sample: Class 3 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.19 0.19 0.19 0.19 0.53 0.00 100% Q50 9.55 9.5 2.56 0.00 100% Q2 2.56 2.56 9.55 21.31 123% 0.5Q2 1.28 1.28 1.28 0.00 0.08Q2 0.20 0.20 0.20 0.00 0.13Q2 0.34 0.34 3.62Q50 34.54 34.54 Incipient Motion of Sediments 0.00 0.00 1.60 0.01 0.02 0.24 0.0001 0.001 0.63 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.00 0.00 0.00 0.00 8.0% 10.0% 12.0% 14.0% 16.0% 18.0% 20.0% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 0 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 34.54 Lower flow bound for sediment loading (cfs): 0.34 Upper flow bound as a fraction of 50year flow*: 3.62 Lower flow bound as a fraction of 2year flow*: 0.135 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 34.54 Flow depth at effective discharge (ft): 0.67 Shear Stress at effective discharge (lb/ft 0.09 Average flow velocity at effective discharge (ft/s): 1.4 Shear velocity at effective discharge (ft/s): 0.2 Effective width at effective discharge (ft): 66.8 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Very fine gravel Fine sand Medium sand 0.00 0.00 0.00 0.0% 2.0% 4.0% 6.0% 8.0% 0.00 0.01 0.10 1.00 10.00 100.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: UMER02 Flow location: UMEQ01 Crosssection: BC11 Channel Slope: 0.5% Sediment sample: Class 2 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.81 0.81 0.81 0.81 0.53 0.00 100% Q50 9.55 9.5 2.56 0.00 100% Q2 2.56 2.56 9.55 21.31 123% 0.5Q2 1.28 1.28 1.28 0.00 0.08Q2 0.20 0.20 0.20 0.00 8.43Q2 21.56 21.56 3.62Q50 34.54 34.54 Incipient Motion of Sediments 0.01 20.65 171.31 0.05 0.58 1.34 0.0056 8.074 66.99 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.00 0.00 0.00 0.00 0.00 40.0% 50.0% 60.0% 70.0% 80.0% 90.0% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 0 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 34.54 Lower flow bound for sediment loading (cfs): 21.56 Upper flow bound as a fraction of 50year flow*: 3.62 Lower flow bound as a fraction of 2year flow*: 8.430 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 34.54 Flow depth at effective discharge (ft): 0.70 Shear Stress at effective discharge (lb/ft 0.13 Average flow velocity at effective discharge (ft/s): 1.3 Shear velocity at effective discharge (ft/s): 0.3 Effective width at effective discharge (ft): 68.9 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Fine gravel Medium sand Coarse sand 0.00 0.00 0.00 0.00 0.0% 10.0% 20.0% 30.0% 40.0% 0.00 0.01 0.10 1.00 10.00 100.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: UMER03 Flow location: UMEQ01 Crosssection: BC11 Channel Slope: 6.1% Sediment sample: Class 1 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.29 0.29 0.29 0.29 0.53 0.00 100% Q50 9.55 9.5 2.56 0.00 100% Q2 2.56 2.56 9.55 21.31 123% 0.5Q2 1.28 1.28 1.28 0.00 0.08Q2 0.20 0.20 0.20 0.00 0.55Q2 1.41 1.41 3.62Q50 34.54 34.54 Incipient Motion of Sediments 0.00 0.80 4.89 0.01 0.14 0.25 0.0001 0.315 1.91 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.00 0.01 0.01 0.01 0.01 0.01 0.01 15.0% 20.0% 25.0% 30.0% 35.0% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 10 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 34.54 Lower flow bound for sediment loading (cfs): 1.41 Upper flow bound as a fraction of 50year flow*: 3.62 Lower flow bound as a fraction of 2year flow*: 0.553 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 34.54 Flow depth at effective discharge (ft): 0.46 Shear Stress at effective discharge (lb/ft 0.83 Average flow velocity at effective discharge (ft/s): 2.8 Shear velocity at effective discharge (ft/s): 0.7 Effective width at effective discharge (ft): 55.8 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Coarse gravel Very coarse sand Very fine gravel 0.00 0.00 0.00 0.00 0.00 0.0% 5.0% 10.0% 15.0% 0.00 0.01 0.10 1.00 10.00 100.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: UMER04 Flow location: UMEQ02 Crosssection: BC12 Channel Slope: 1.3% Sediment sample: Class 2 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.20 0.20 0.20 0.20 0.16 0.00 100% Q50 2.86 2.9 0.77 0.00 100% Q2 0.77 0.77 2.86 6.39 123% 0.5Q2 0.38 0.38 0.38 0.00 0.08Q2 0.06 0.06 0.06 0.00 0.38Q2 0.29 0.29 3.62Q50 10.36 10.36 Incipient Motion of Sediments 0.00 0.11 1.80 0.03 0.36 0.98 0.0002 0.150 2.34 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.00 0.00 0.00 0.00 10.0% 15.0% 20.0% 25.0% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 1 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 10.36 Lower flow bound for sediment loading (cfs): 0.29 Upper flow bound as a fraction of 50year flow*: 3.62 Lower flow bound as a fraction of 2year flow*: 0.383 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 10.36 Flow depth at effective discharge (ft): 1.84 Shear Stress at effective discharge (lb/ft 0.38 Average flow velocity at effective discharge (ft/s): 2.1 Shear velocity at effective discharge (ft/s): 0.4 Effective width at effective discharge (ft): 10.2 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Medium gravel Coarse sand Very coarse sand 0.00 0.00 0.00 0.0% 5.0% 10.0% 0.00 0.00 0.01 0.10 1.00 10.00 100.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: UMER05 Flow location: UMEQ02 Crosssection: BC12 Channel Slope: 6.0% Sediment sample: Class 1 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.20 0.20 0.20 0.20 0.16 0.00 100% Q50 2.86 2.9 0.77 0.00 100% Q2 0.77 0.77 2.86 6.39 123% 0.5Q2 0.38 0.38 0.38 0.00 0.08Q2 0.06 0.06 0.06 0.00 0.2Q2 0.16 0.16 3.62Q50 10.36 10.36 Incipient Motion of Sediments 0.00 0.03 0.15 0.01 0.16 0.30 0.0000 0.035 0.20 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.03 0.04 0.05 0.06 10.0% 15.0% 20.0% 25.0% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 8 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 10.36 Lower flow bound for sediment loading (cfs): 0.16 Upper flow bound as a fraction of 50year flow*: 3.62 Lower flow bound as a fraction of 2year flow*: 0.205 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 10.36 Flow depth at effective discharge (ft): 1.37 Shear Stress at effective discharge (lb/ft 1.81 Average flow velocity at effective discharge (ft/s): 4.6 Shear velocity at effective discharge (ft/s): 1.0 Effective width at effective discharge (ft): 4.6 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Very coarse gravel Very fine gravel Fine gravel 0.00 0.01 0.02 0.0% 5.0% 10.0% 0.00 0.00 0.01 0.10 1.00 10.00 100.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: UMER06 Flow location: UMEQ02 Crosssection: BC11 Channel Slope: 3.9% Sediment sample: Class 2 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.30 0.30 0.30 0.30 0.16 0.00 100% Q50 2.86 2.9 0.77 0.00 100% Q2 0.77 0.77 2.86 6.39 123% 0.5Q2 0.38 0.38 0.38 0.00 0.08Q2 0.06 0.06 0.06 0.00 0.65Q2 0.50 0.50 3.62Q50 10.36 10.36 Incipient Motion of Sediments 0.00 0.29 4.82 0.01 0.11 0.26 0.0002 0.382 6.28 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.00 0.00 0.00 0.00 0.00 15.0% 20.0% 25.0% 30.0% 35.0% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 1 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 10.36 Lower flow bound for sediment loading (cfs): 0.50 Upper flow bound as a fraction of 50year flow*: 3.62 Lower flow bound as a fraction of 2year flow*: 0.647 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 10.36 Flow depth at effective discharge (ft): 0.34 Shear Stress at effective discharge (lb/ft 0.35 Average flow velocity at effective discharge (ft/s): 1.7 Shear velocity at effective discharge (ft/s): 0.4 Effective width at effective discharge (ft): 41.4 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Medium gravel Coarse sand Very coarse sand 0.00 0.00 0.00 0.00 0.0% 5.0% 10.0% 15.0% 0.00 0.00 0.01 0.10 1.00 10.00 100.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: UMWR01 Flow location: UMWQ01 Crosssection: BC09 Channel Slope: 0.0% Sediment sample: Class 3 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.03 0.03 0.03 0.03 0.14 0.16 15% Q50 3.00 3.0 0.74 7.36 890% Q2 0.74 0.74 3.00 24.79 725% 0.5Q2 0.37 0.37 0.37 3.68 0.08Q2 0.06 0.06 0.06 0.59 0.33Q2 0.25 0.25 3.25Q50 9.77 9.77 Incipient Motion of Sediments 0.01 0.16 26.31 0.15 0.46 3.54 0.0082 0.218 35.40 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.00 0.00 0.00 0.00 1.5% 2.0% 2.5% 3.0% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 3 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 9.77 Lower flow bound for sediment loading (cfs): 0.25 Upper flow bound as a fraction of 50year flow*: 3.25 Lower flow bound as a fraction of 2year flow*: 0.331 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 2.22 Flow depth at effective discharge (ft): 1.13 Shear Stress at effective discharge (lb/ft 0.01 Average flow velocity at effective discharge (ft/s): 0.5 Shear velocity at effective discharge (ft/s): 0.1 Effective width at effective discharge (ft): 6.7 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Coarse sand Very fine sand Fine sand 0.00 0.00 0.00 0.0% 0.5% 1.0% 0.00 0.01 0.10 1.00 10.00 100.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: UMWR02 Flow location: UMWQ02 Crosssection: BC09 Channel Slope: 4.4% Sediment sample: Class 2 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.02 0.02 0.02 0.02 0.11 0.13 15% Q50 2.43 2.4 0.60 5.95 890% Q2 0.60 0.60 2.43 20.05 725% 0.5Q2 0.30 0.30 0.30 2.98 0.08Q2 0.05 0.05 0.05 0.48 0.1Q2 0.06 0.06 3.24Q50 7.88 7.88 Incipient Motion of Sediments 0.00 0.02 0.21 0.01 0.09 0.24 0.0000 0.026 0.36 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.04 0.05 0.06 0.07 0.08 0.09 1.0% 1.5% 2.0% 2.5% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 3,136 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 7.88 Lower flow bound for sediment loading (cfs): 0.06 Upper flow bound as a fraction of 50year flow*: 3.24 Lower flow bound as a fraction of 2year flow*: 0.102 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 1.02 Flow depth at effective discharge (ft): 0.41 Shear Stress at effective discharge (lb/ft 0.34 Average flow velocity at effective discharge (ft/s): 1.7 Shear velocity at effective discharge (ft/s): 0.4 Effective width at effective discharge (ft): 4.6 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Medium gravel Coarse sand Very coarse sand 0.00 0.01 0.02 0.03 0.04 0.0% 0.5% 1.0% 0.00 0.01 0.10 1.00 10.00 100.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: UMWR03 Flow location: UMWQ02 Crosssection: BC10 Channel Slope: 5.1% Sediment sample: Class 1 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.03 0.03 0.03 0.03 0.11 0.13 15% Q50 2.43 2.4 0.60 5.95 890% Q2 0.60 0.60 2.43 20.05 725% 0.5Q2 0.30 0.30 0.30 2.98 0.08Q2 0.05 0.05 0.05 0.48 0.37Q2 0.22 0.22 3.41Q50 8.30 8.30 Incipient Motion of Sediments 0.00 0.14 0.64 0.01 0.13 0.23 0.0001 0.240 1.06 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.03 0.04 0.05 0.06 1.5% 2.0% 2.5% 3.0% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 2,148 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 8.30 Lower flow bound for sediment loading (cfs): 0.22 Upper flow bound as a fraction of 50year flow*: 3.41 Lower flow bound as a fraction of 2year flow*: 0.366 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 1.79 Flow depth at effective discharge (ft): 0.35 Shear Stress at effective discharge (lb/ft 0.61 Average flow velocity at effective discharge (ft/s): 2.3 Shear velocity at effective discharge (ft/s): 0.6 Effective width at effective discharge (ft): 4.0 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Coarse gravel Very coarse sand Very fine gravel 0.00 0.01 0.02 0.0% 0.5% 1.0% 0.00 0.01 0.10 1.00 10.00 100.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: UMWR04 Flow location: UMWQ03 Crosssection: BC10 Channel Slope: 4.6% Sediment sample: Class 2 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.02 0.02 0.02 0.02 0.05 0.06 15% Q50 1.11 1.1 0.27 2.71 890% Q2 0.27 0.27 1.11 9.12 725% 0.5Q2 0.14 0.14 0.14 1.35 0.08Q2 0.02 0.02 0.02 0.22 0.2Q2 0.05 0.05 3.21Q50 3.55 3.55 Incipient Motion of Sediments 0.00 0.03 0.32 0.01 0.07 0.18 0.0001 0.096 1.17 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.02 0.02 0.03 0.03 1.0% 1.5% 2.0% 2.5% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 1,032 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 3.55 Lower flow bound for sediment loading (cfs): 0.05 Upper flow bound as a fraction of 50year flow*: 3.21 Lower flow bound as a fraction of 2year flow*: 0.196 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 0.51 Flow depth at effective discharge (ft): 0.22 Shear Stress at effective discharge (lb/ft 0.33 Average flow velocity at effective discharge (ft/s): 1.5 Shear velocity at effective discharge (ft/s): 0.4 Effective width at effective discharge (ft): 2.8 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Medium gravel Coarse sand Very coarse sand 0.00 0.01 0.01 0.0% 0.5% 1.0% 0.00 0.00 0.01 0.10 1.00 10.00 100.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: UMWR05 Flow location: UMWQ03 Crosssection: BC12 Channel Slope: 5.9% Sediment sample: Class 1 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.02 0.02 0.02 0.02 0.05 0.06 15% Q50 1.11 1.1 0.27 2.71 890% Q2 0.27 0.27 1.11 9.12 725% 0.5Q2 0.14 0.14 0.14 1.35 0.08Q2 0.02 0.02 0.02 0.22 0.2Q2 0.05 0.05 3.21Q50 3.55 3.55 Incipient Motion of Sediments 0.00 0.03 0.15 0.01 0.16 0.30 0.0000 0.097 0.54 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.03 0.04 0.05 0.06 0.07 1.0% 1.5% 2.0% 2.5% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 1,746 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 3.55 Lower flow bound for sediment loading (cfs): 0.05 Upper flow bound as a fraction of 50year flow*: 3.21 Lower flow bound as a fraction of 2year flow*: 0.196 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 0.51 Flow depth at effective discharge (ft): 0.47 Shear Stress at effective discharge (lb/ft 0.62 Average flow velocity at effective discharge (ft/s): 2.2 Shear velocity at effective discharge (ft/s): 0.6 Effective width at effective discharge (ft): 1.4 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Coarse gravel Very coarse sand Very fine gravel 0.00 0.01 0.02 0.03 0.0% 0.5% 1.0% 0.00 0.00 0.01 0.10 1.00 10.00 100.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: WCR01 Flow location: WCQ01 Crosssection: BC01 Channel Slope: 0.0% Sediment sample: Class 3 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.03 0.03 0.03 0.03 1.30 1.44 11% Q50 30.73 30.7 8.25 59.68 623% Q2 8.25 8.25 30.73 233.27 659% 0.5Q2 4.13 4.13 4.13 29.84 0.08Q2 0.66 0.66 0.66 4.77 0.19Q2 1.55 1.55 1.67Q50 51.27 51.27 Incipient Motion of Sediments 0.12 1.01 34.82 0.52 0.98 3.07 0.0150 0.122 4.22 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.00 0.00 0.00 0.00 1.5% 2.0% 2.5% 3.0% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 6 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 51.27 Lower flow bound for sediment loading (cfs): 1.55 Upper flow bound as a fraction of 50year flow*: 1.67 Lower flow bound as a fraction of 2year flow*: 0.187 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 10.66 Flow depth at effective discharge (ft): 2.69 Shear Stress at effective discharge (lb/ft 0.01 Average flow velocity at effective discharge (ft/s): 0.5 Shear velocity at effective discharge (ft/s): 0.1 Effective width at effective discharge (ft): 19.6 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Medium sand Very fine sand Fine sand 0.00 0.00 0.00 0.0% 0.5% 1.0% 0.01 0.10 1.00 10.00 100.00 1000.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: WCR02 Flow location: WCQ01 Crosssection: BC01 Channel Slope: 0.3% Sediment sample: Class 3 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.02 0.02 0.02 0.02 1.30 1.44 11% Q50 30.73 30.7 8.25 59.68 623% Q2 8.25 8.25 30.73 233.27 659% 0.5Q2 4.13 4.13 4.13 29.84 0.08Q2 0.66 0.66 0.66 4.77 0.06Q2 0.46 0.46 1.83Q50 56.08 56.08 Incipient Motion of Sediments 0.00 0.00 0.18 0.01 0.03 0.35 0.0000 0.000 0.02 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.00 0.00 0.01 0.01 0.01 1.0% 1.5% 2.0% 2.5% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 2,484 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 56.08 Lower flow bound for sediment loading (cfs): 0.46 Upper flow bound as a fraction of 50year flow*: 1.83 Lower flow bound as a fraction of 2year flow*: 0.056 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 10.66 Flow depth at effective discharge (ft): 1.21 Shear Stress at effective discharge (lb/ft 0.13 Average flow velocity at effective discharge (ft/s): 2.1 Shear velocity at effective discharge (ft/s): 0.3 Effective width at effective discharge (ft): 8.5 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Fine gravel Medium sand Coarse sand 0.00 0.00 0.00 0.00 0.0% 0.5% 1.0% 0.01 0.10 1.00 10.00 100.00 1000.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: WCR03 Flow location: WCQ02 Crosssection: BC01 Channel Slope: 0.5% Sediment sample: Class 2 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.03 0.03 0.03 0.03 0.87 1.01 16% Q50 22.72 22.7 6.03 36.24 501% Q2 6.03 6.03 22.72 154.67 581% 0.5Q2 3.02 3.02 3.02 18.12 0.08Q2 0.48 0.48 0.48 2.90 0.72Q2 4.34 4.34 2.89Q50 65.60 65.60 Incipient Motion of Sediments 0.00 3.71 26.56 0.07 0.80 1.62 0.0004 0.615 4.40 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.00 0.00 0.00 0.00 0.00 0.00 2.0% 2.5% 3.0% 3.5% 4.0% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 301 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 65.60 Lower flow bound for sediment loading (cfs): 4.34 Upper flow bound as a fraction of 50year flow*: 2.89 Lower flow bound as a fraction of 2year flow*: 0.720 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 16.51 Flow depth at effective discharge (ft): 1.33 Shear Stress at effective discharge (lb/ft 0.21 Average flow velocity at effective discharge (ft/s): 2.7 Shear velocity at effective discharge (ft/s): 0.3 Effective width at effective discharge (ft): 8.9 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Fine gravel Medium sand Coarse sand 0.00 0.00 0.00 0.00 0.00 0.0% 0.5% 1.0% 1.5% 0.01 0.10 1.00 10.00 100.00 1000.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: WCR04 Flow location: WCQ02 Crosssection: BC01 Channel Slope: 3.5% Sediment sample: Class 2 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.02 0.02 0.02 0.02 0.87 1.01 16% Q50 22.72 22.7 6.03 36.24 501% Q2 6.03 6.03 22.72 154.67 581% 0.5Q2 3.02 3.02 3.02 18.12 0.08Q2 0.48 0.48 0.48 2.90 0.07Q2 0.39 0.39 1.85Q50 42.03 42.03 Incipient Motion of Sediments 0.00 0.02 0.77 0.01 0.12 0.38 0.0000 0.004 0.13 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.10 0.15 0.20 0.25 0.8% 1.0% 1.2% 1.4% 1.6% 1.8% 2.0% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 28,930 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 42.03 Lower flow bound for sediment loading (cfs): 0.39 Upper flow bound as a fraction of 50year flow*: 1.85 Lower flow bound as a fraction of 2year flow*: 0.065 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 3.97 Flow depth at effective discharge (ft): 0.62 Shear Stress at effective discharge (lb/ft 0.49 Average flow velocity at effective discharge (ft/s): 3.2 Shear velocity at effective discharge (ft/s): 0.5 Effective width at effective discharge (ft): 5.4 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Medium gravel Coarse sand Very coarse sand 0.00 0.05 0.10 0.0% 0.2% 0.4% 0.6% 0.8% 0.01 0.10 1.00 10.00 100.00 1000.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: WCR05 Flow location: WCQ02 Crosssection: XS477 Channel Slope: 4.4% Sediment sample: Class 2 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.02 0.02 0.02 0.02 0.87 1.01 16% Q50 22.72 22.7 6.03 36.24 501% Q2 6.03 6.03 22.72 154.67 581% 0.5Q2 3.02 3.02 3.02 18.12 0.08Q2 0.48 0.48 0.48 2.90 0.07Q2 0.45 0.45 1.69Q50 38.45 38.45 Incipient Motion of Sediments 0.00 0.09 0.48 0.01 0.06 0.12 0.0000 0.015 0.08 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.15 0.20 0.25 0.30 0.35 0.8% 1.0% 1.2% 1.4% 1.6% 1.8% 2.0% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 54,005 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 38.45 Lower flow bound for sediment loading (cfs): 0.45 Upper flow bound as a fraction of 50year flow*: 1.69 Lower flow bound as a fraction of 2year flow*: 0.074 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 3.97 Flow depth at effective discharge (ft): 0.40 Shear Stress at effective discharge (lb/ft 0.84 Average flow velocity at effective discharge (ft/s): 3.4 Shear velocity at effective discharge (ft/s): 0.7 Effective width at effective discharge (ft): 3.8 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Coarse gravel Very coarse sand Very fine gravel 0.00 0.05 0.10 0.15 0.0% 0.2% 0.4% 0.6% 0.8% 0.01 0.10 1.00 10.00 100.00 1000.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: WCR06 Flow location: WCQ03 Crosssection: XS477 Channel Slope: 5.0% Sediment sample: Class 2 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.03 0.03 0.03 0.03 0.70 0.82 17% Q50 19.47 19.5 5.41 31.99 491% Q2 5.41 5.41 19.47 142.84 633% 0.5Q2 2.71 2.71 2.71 15.99 0.08Q2 0.43 0.43 0.43 2.56 0.07Q2 0.37 0.37 1.8Q50 34.97 34.97 Incipient Motion of Sediments 0.00 0.07 0.35 0.01 0.05 0.11 0.0000 0.012 0.07 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.15 0.20 0.25 0.30 0.35 1.5% 2.0% 2.5% 3.0% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 54,498 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 34.97 Lower flow bound for sediment loading (cfs): 0.37 Upper flow bound as a fraction of 50year flow*: 1.80 Lower flow bound as a fraction of 2year flow*: 0.069 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 3.84 Flow depth at effective discharge (ft): 0.40 Shear Stress at effective discharge (lb/ft 0.97 Average flow velocity at effective discharge (ft/s): 3.2 Shear velocity at effective discharge (ft/s): 0.7 Effective width at effective discharge (ft): 3.8 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Coarse gravel Very coarse sand Very fine gravel 0.00 0.05 0.10 0.15 0.0% 0.5% 1.0% 0.00 0.01 0.10 1.00 10.00 100.00 1000.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: WCR07 Flow location: WCQ03 Crosssection: BC03 Channel Slope: 7.1% Sediment sample: Class 1 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.03 0.03 0.03 0.03 0.70 0.82 17% Q50 19.47 19.5 5.41 31.99 491% Q2 5.41 5.41 19.47 142.84 633% 0.5Q2 2.71 2.71 2.71 15.99 0.08Q2 0.43 0.43 0.43 2.56 0.07Q2 0.37 0.37 1.8Q50 34.97 34.97 Incipient Motion of Sediments 0.00 0.09 0.30 0.01 0.09 0.14 0.0000 0.017 0.06 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.40 0.50 0.60 0.70 0.80 1.5% 2.0% 2.5% 3.0% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 80,606 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 34.97 Lower flow bound for sediment loading (cfs): 0.37 Upper flow bound as a fraction of 50year flow*: 1.80 Lower flow bound as a fraction of 2year flow*: 0.069 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 3.84 Flow depth at effective discharge (ft): 0.45 Shear Stress at effective discharge (lb/ft 1.27 Average flow velocity at effective discharge (ft/s): 3.1 Shear velocity at effective discharge (ft/s): 0.8 Effective width at effective discharge (ft): 4.2 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Very coarse gravel Very fine gravel Fine gravel 0.00 0.10 0.20 0.30 0.0% 0.5% 1.0% 0.00 0.01 0.10 1.00 10.00 100.00 1000.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: WCR08 Flow location: WCQ03 Crosssection: BC05 Channel Slope: 3.1% Sediment sample: Class 2 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.03 0.03 0.03 0.03 0.70 0.82 17% Q50 19.47 19.5 5.41 31.99 491% Q2 5.41 5.41 19.47 142.84 633% 0.5Q2 2.71 2.71 2.71 15.99 0.08Q2 0.43 0.43 0.43 2.56 0.05Q2 0.29 0.29 1.69Q50 32.89 32.89 Incipient Motion of Sediments 0.00 0.02 0.27 0.01 0.12 0.31 0.0000 0.004 0.05 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.08 0.10 0.12 0.14 0.16 0.18 1.5% 2.0% 2.5% 3.0% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 27,720 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 32.89 Lower flow bound for sediment loading (cfs): 0.29 Upper flow bound as a fraction of 50year flow*: 1.69 Lower flow bound as a fraction of 2year flow*: 0.054 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 3.84 Flow depth at effective discharge (ft): 0.84 Shear Stress at effective discharge (lb/ft 0.72 Average flow velocity at effective discharge (ft/s): 2.5 Shear velocity at effective discharge (ft/s): 0.6 Effective width at effective discharge (ft): 4.0 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Coarse gravel Very coarse sand Very fine gravel 0.00 0.02 0.04 0.06 0.08 0.0% 0.5% 1.0% 0.00 0.01 0.10 1.00 10.00 100.00 1000.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: WCR09 Flow location: WCQ03 Crosssection: BC04 Channel Slope: 4.5% Sediment sample: Class 2 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.03 0.03 0.03 0.03 0.70 0.82 17% Q50 19.47 19.5 5.41 31.99 491% Q2 5.41 5.41 19.47 142.84 633% 0.5Q2 2.71 2.71 2.71 15.99 0.08Q2 0.43 0.43 0.43 2.56 0.06Q2 0.33 0.33 1.69Q50 32.89 32.89 Incipient Motion of Sediments 0.00 0.04 0.32 0.01 0.07 0.15 0.0000 0.008 0.06 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.15 0.20 0.25 0.30 0.35 1.5% 2.0% 2.5% 3.0% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 43,361 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 32.89 Lower flow bound for sediment loading (cfs): 0.33 Upper flow bound as a fraction of 50year flow*: 1.69 Lower flow bound as a fraction of 2year flow*: 0.061 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 3.84 Flow depth at effective discharge (ft): 0.47 Shear Stress at effective discharge (lb/ft 0.80 Average flow velocity at effective discharge (ft/s): 2.5 Shear velocity at effective discharge (ft/s): 0.6 Effective width at effective discharge (ft): 5.3 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Coarse gravel Very coarse sand Very fine gravel 0.00 0.05 0.10 0.15 0.0% 0.5% 1.0% 0.00 0.01 0.10 1.00 10.00 100.00 1000.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: WCR10 Flow location: WCQ04 Crosssection: BC04 Channel Slope: 3.4% Sediment sample: Class 2 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.03 0.03 0.03 0.03 0.53 0.62 17% Q50 14.79 14.8 4.11 24.29 491% Q2 4.11 4.11 14.79 108.49 633% 0.5Q2 2.06 2.06 2.06 12.15 0.08Q2 0.33 0.33 0.33 1.94 0.07Q2 0.30 0.30 1.8Q50 26.57 26.57 Incipient Motion of Sediments 0.00 0.08 0.57 0.01 0.09 0.20 0.0000 0.019 0.14 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.08 0.10 0.12 0.14 0.16 0.18 1.5% 2.0% 2.5% 3.0% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 17,968 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 26.57 Lower flow bound for sediment loading (cfs): 0.30 Upper flow bound as a fraction of 50year flow*: 1.80 Lower flow bound as a fraction of 2year flow*: 0.073 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 2.92 Flow depth at effective discharge (ft): 0.42 Shear Stress at effective discharge (lb/ft 0.54 Average flow velocity at effective discharge (ft/s): 2.3 Shear velocity at effective discharge (ft/s): 0.5 Effective width at effective discharge (ft): 4.8 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Coarse gravel Coarse sand Very coarse sand 0.00 0.02 0.04 0.06 0.08 0.0% 0.5% 1.0% 0.00 0.00 0.01 0.10 1.00 10.00 100.00 1000.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: WCR11 Flow location: WCQ04 Crosssection: BC04 Channel Slope: 4.0% Sediment sample: Class 2 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.03 0.03 0.03 0.03 0.53 0.62 17% Q50 14.79 14.8 4.11 24.29 491% Q2 4.11 4.11 14.79 108.49 633% 0.5Q2 2.06 2.06 2.06 12.15 0.08Q2 0.33 0.33 0.33 1.94 0.07Q2 0.28 0.28 1.8Q50 26.57 26.57 Incipient Motion of Sediments 0.00 0.06 0.44 0.01 0.08 0.17 0.0000 0.016 0.11 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.10 0.15 0.20 0.25 1.5% 2.0% 2.5% 3.0% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 23,523 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 26.57 Lower flow bound for sediment loading (cfs): 0.28 Upper flow bound as a fraction of 50year flow*: 1.80 Lower flow bound as a fraction of 2year flow*: 0.069 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 2.92 Flow depth at effective discharge (ft): 0.40 Shear Stress at effective discharge (lb/ft 0.62 Average flow velocity at effective discharge (ft/s): 2.4 Shear velocity at effective discharge (ft/s): 0.6 Effective width at effective discharge (ft): 4.7 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Coarse gravel Very coarse sand Very fine gravel 0.00 0.05 0.10 0.0% 0.5% 1.0% 0.00 0.00 0.01 0.10 1.00 10.00 100.00 1000.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- MFA Inputs Reach: WCR12 Flow location: WCQ04 Crosssection: BC04 Channel Slope: 3.0% Sediment sample: Class 2 Flow scenario: Existing Lowflow Hydrology Natural Existing % Change Plot Plot Plot Plot 0 0.03 0.03 0.03 0.03 0.53 0.62 17% Q50 14.79 14.8 4.11 24.29 491% Q2 4.11 4.11 14.79 108.49 633% 0.5Q2 2.06 2.06 2.06 12.15 0.08Q2 0.33 0.33 0.33 1.94 0.08Q2 0.32 0.32 1.8Q50 26.57 26.57 Incipient Motion of Sediments 0.00 0.09 0.68 0.01 0.10 0.22 0.0000 0.022 0.17 Geomorphically Significant Flows 2year Flow, Q 2 Median (50% exceedence) Parameter 50year Flow, Q 50 MR#5 Threshold, 0.08Q 2 MR#7 Threshold, 0.5Q 2 Fraction of natural Q2 Depth of flow (ft) Flow rate (cfs) Parameter Incipient Motion D 84 D 50 D 16 0.08 0.10 0.12 0.14 0.16 1.5% 2.0% 2.5% 3.0% ediment Transport Rate (ft3/s/ft) malized Flow and Sediment Curves Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. This is a draft version of the spreadsheet and is not intended to be a final representation of the work done or recommendations made by Brown and Caldwell. It should not be relied upon; consult the final version. DRAFT Geomorphically Significant Flows Total area under sediment loading curve (t/yr): 15,030 Desired level of control (percent of loading curve): 98% Upper flow bound for sediment loading (cfs): 26.57 Lower flow bound for sediment loading (cfs): 0.32 Upper flow bound as a fraction of 50year flow*: 1.80 Lower flow bound as a fraction of 2year flow*: 0.078 *Flows based on "Natural" conditions Effective Discharge Conditions Flow at the peak rate of sediment loading (cfs): 2.92 Flow depth at effective discharge (ft): 0.43 Shear Stress at effective discharge (lb/ft 0.50 Average flow velocity at effective discharge (ft/s): 2.2 Shear velocity at effective discharge (ft/s): 0.5 Effective width at effective discharge (ft): 4.9 Largest mobilized sediment: Largest fully suspended sediment: Sediment beginning to settle out: Coarse gravel Coarse sand Very coarse sand 0.00 0.02 0.04 0.06 0.0% 0.5% 1.0% 0.00 0.00 0.01 0.10 1.00 10.00 100.00 1000.00 Sedimen Normalize Stream Discharge (cfs) Flow Frequency Geo. Sig. Flow Bounds Sediment Loading Curve MR#7 Threshold, 0.5Q2 Sediment Transport Capacity MR#5 Threshold, 0.08Q2 ---PAGE BREAK--- ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Geomorphic Magnitude-Frequency Analysis B DRAFT for review purposes only. Use of contents on this sheet is subject to the limitations specified at the beginning of this document. CCSRAP E (GeomorphicMFA_TechMemo_20121121(v5))_track changes accepted.docx Attachment C: Tabulated Results Geomorphically Significant Flow Bounds and Regulatory Thresholds ---PAGE BREAK--- This page intentionally left blank. ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Geomorphic Magnitude-Frequency Analysis C DRAFT for review purposes only. Use of contents on this sheet is subject to the limitations specified at the beginning of this document. CCSRAP E (GeomorphicMFA_TechMemo_20121121(v5))_track changes accepted.docx Table C-1. Geomorphically Significant Flow Ranges for Clarks Creek Reach Upper bound Lower bound 50-year discharge forested conditions (cfs) Calculated geomorphically significant flow bound (cfs) Geo. sig. flow bound as a percentage of 50-year forested 2-year discharge forested conditions (cfs) Calculated geomorphically significant flow bound (cfs) Geo. sig. flow bound as a percentage of 2-year forested 50% of 2-year forested discharge 8% of 2-year forested discharge CC-R01 164.2 185.5 113% 81.0 39.5 49% 40.48 6.48 CC-R02 164.2 185.5 113% 81.0 39.5 49% 40.48 6.48 CC-R03 164.2 185.5 113% 81.0 39.5 49% 40.48 6.48 CC-R04 164.2 173.7 106% 81.0 39.5 49% 40.48 6.48 CC-R05 147.5 159.3 108% 80.7 38.5 48% 40.35 6.46 CC-R06 147.5 155.3 105% 80.7 38.5 48% 40.35 6.46 CC-R07 147.5 163.4 111% 80.7 38.5 48% 40.35 6.46 CC-R08 131.2 145.6 111% 77.7 37.4 48% 38.85 6.22 CC-R09 131.2 145.6 111% 77.7 37.4 48% 38.85 6.22 CC-R10 131.2 142.2 108% 77.7 37.4 48% 38.85 6.22 CC-R11 104.6 115.5 110% 68.2 37.1 54% 34.10 5.46 CC-R12 104.6 115.5 110% 68.2 37.1 54% 34.10 5.46 CC-R13 101.0 97.9 97% 68.3 36.8 54% 34.17 5.47 CC-R14 88.0 82.8 94% 63.7 35.5 56% 31.84 5.09 CC-R15 27.2 25.7 95% 17.0 9.1 54% 8.51 1.36 CC-R16 27.2 23.4 86% 17.0 8.5 50% 8.51 1.36 CC-R17 15.7 17.0 108% 6.6 2.5 38% 3.28 0.52 CC-R18 15.7 17.7 113% 6.6 2.4 37% 3.28 0.52 CC-R19 7.6 19.8 262% 1.9 0.2 11% 0.94 0.15 CC-R20 7.6 23.5 310% 1.9 0.5 28% 0.94 0.15 CC-R21 7.6 18.8 247% 1.9 0.1 7% 0.94 0.15 CC-R22 7.6 18.8 247% 1.9 0.2 8% 0.94 0.15 CC-R23 7.6 19.8 262% 1.9 0.1 5% 0.94 0.15 CC-R24 4.5 9.9 221% 1.1 0.1 9% 0.55 0.09 CC-R25 4.5 13.1 294% 1.1 0.2 15% 0.55 0.09 UCT-R01 1.6 4.0 248% 0.4 0.0 13% 0.18 0.03 ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Geomorphic Magnitude-Frequency Analysis C DRAFT for review purposes only. Use of contents on this sheet is subject to the limitations specified at the beginning of this document. CCSRAP E (GeomorphicMFA_TechMemo_20121121(v5))_track changes accepted.docx Table C-2. Geomorphically Significant Flow Ranges for Diru Creek Reach Upper bound Lower bound 50-year discharge forested conditions (cfs) Calculated geomorphically significant flow bound (cfs) Geo. sig. flow bound as a percentage of 50-year forested 2-year discharge forested conditions (cfs) Calculated geomorphically significant flow bound (cfs) Geo. sig. flow bound as a percentage of 2-year forested 50% of 2-year forested discharge 8% of 2-year forested discharge DC-R01 16.6 29.7 180% 2.8 0.7 26% 1.41 0.23 DC-R02 16.6 52.3 316% 2.8 3.2 113% 1.41 0.23 DC-R03 13.1 27.1 206% 3.3 0.6 19% 1.63 0.26 DC-R04 13.1 27.1 206% 3.3 0.7 20% 1.63 0.26 DC-R05 13.1 28.7 219% 3.3 0.7 20% 1.63 0.26 DC-R06 10.2 26.7 261% 2.5 0.3 11% 1.25 0.20 DC-R07 10.2 28.3 276% 2.5 0.5 18% 1.25 0.20 DC-R08 10.2 33.6 329% 2.5 1.2 46% 1.25 0.20 DC-R09 7.3 28.4 389% 1.8 1.0 58% 0.89 0.14 DC-R10 7.3 60.5 828% 1.8 2.2 124% 0.89 0.14 ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Geomorphic Magnitude-Frequency Analysis C DRAFT for review purposes only. Use of contents on this sheet is subject to the limitations specified at the beginning of this document. CCSRAP E (GeomorphicMFA_TechMemo_20121121(v5))_track changes accepted.docx Table C-3. Geomorphically Significant Flow Ranges for Meeker Creek Reach Upper bound Lower bound 50-year discharge forested conditions (cfs) Calculated geomorphically significant flow bound (cfs) Geo. sig. flow bound as a percentage of 50-year forested 2-year discharge forested conditions (cfs) Calculated geomorphically significant flow bound (cfs) Geo. sig. flow bound as a percentage of 2-year forested 50% of 2- year forested discharge 8% of 2- year forested discharge MC-R01 32.6 67.1 206% 8.2 0.5 6% 4.09 0.66 MC-R02 22.0 51.9 236% 5.5 0.4 7% 2.77 0.44 MC-R03 14.4 33.4 232% 3.6 0.2 5% 1.80 0.29 MC-R04 14.4 31.5 219% 3.6 0.2 5% 1.80 0.29 MC-R05 6.0 45.7 761% 1.5 1.8 119% 0.75 0.12 UMW- R01 3.0 9.8 325% 0.7 0.2 33% 0.37 0.06 UMW- R02 2.4 7.9 324% 0.6 0.1 10% 0.30 0.05 UMW- R03 2.4 8.3 341% 0.6 0.2 37% 0.30 0.05 UMW- R04 1.1 3.5 321% 0.3 0.1 20% 0.14 0.02 UMW- R05 1.1 3.5 321% 0.3 0.1 20% 0.14 0.02 ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Geomorphic Magnitude-Frequency Analysis C DRAFT for review purposes only. Use of contents on this sheet is subject to the limitations specified at the beginning of this document. CCSRAP E (GeomorphicMFA_TechMemo_20121121(v5))_track changes accepted.docx Table C-4. Geomorphically Significant Flow Ranges for Rody Creek Reach Upper bound Lower bound 50-year discharge forested conditions (cfs) Calculated geomorphically significant flow bound (cfs) Geo. sig. flow bound as a percentage of 50-year forested 2-year discharge forested conditions (cfs) Calculated geomorphically significant flow bound (cfs) Geo. sig. flow bound as a percentage of 2-year forested 50% of 2- year forested discharge 8% of 2- year forested discharge RC-R01 14.0 23.4 167% 4.6 1.0 21% 2.30 0.37 RC-R02 14.0 32.1 229% 4.6 1.5 32% 2.30 0.37 RC-R03 10.8 30.6 283% 2.7 0.6 21% 1.35 0.22 RC-R04 10.8 28.9 267% 2.7 0.3 10% 1.35 0.22 RC-R05 10.8 27.3 252% 2.7 0.2 9% 1.35 0.22 RC-R06 10.8 28.9 267% 2.7 0.3 10% 1.35 0.22 RC-R07 10.8 32.5 299% 2.7 0.4 14% 1.35 0.22 RC-R08 9.3 25.4 272% 2.5 0.2 10% 1.26 0.20 RC-R09 9.3 28.5 305% 2.5 0.4 17% 1.26 0.20 RC-R10 8.3 49.8 604% 2.2 2.7 121% 1.11 0.18 ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Geomorphic Magnitude-Frequency Analysis C DRAFT for review purposes only. Use of contents on this sheet is subject to the limitations specified at the beginning of this document. CCSRAP E (GeomorphicMFA_TechMemo_20121121(v5))_track changes accepted.docx Table C-5. Geomorphically Significant Flow Ranges for Silver Creek Reach Upper bound Lower bound 50-year discharge forested conditions (cfs) Calculated geomorphically significant flow bound (cfs) Geo. sig. flow bound as a percentage of 50-year forested 2-year discharge forested conditions (cfs) Calculated geomorphically significant flow bound (cfs) Geo. sig. flow bound as a percentage of 2-year forested 50% of 2-year forested discharge 8% of 2-year forested discharge SC-R01 6.6 28.1 424% 1.7 1.7 99% 0.87 0.14 SC-R02 6.6 24.5 371% 1.7 0.6 35% 0.87 0.14 SC-R03 6.6 23.5 354% 1.7 0.1 8% 0.87 0.14 SC-R04 4.4 22.4 504% 1.2 0.4 32% 0.60 0.10 SC-R05 4.4 21.2 477% 1.2 0.2 18% 0.60 0.10 SC-R06 4.4 20.0 451% 1.2 0.2 20% 0.60 0.10 SC-R07 4.4 20.0 451% 1.2 0.3 24% 0.60 0.10 SC-R08 4.4 19.0 427% 1.2 0.2 18% 0.60 0.10 SC-R09 3.3 15.7 474% 0.9 0.2 28% 0.44 0.07 ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Geomorphic Magnitude-Frequency Analysis C DRAFT for review purposes only. Use of contents on this sheet is subject to the limitations specified at the beginning of this document. CCSRAP E (GeomorphicMFA_TechMemo_20121121(v5))_track changes accepted.docx Table C-6. Geomorphically Significant Flow Ranges for Woodland Creek Reach Upper bound Lower bound 50-year discharge forested conditions (cfs) Calculated geomorphically significant flow bound (cfs) Geo. sig. flow bound as a percentage of 50-year forested 2-year discharge forested conditions (cfs) Calculated geomorphically significant flow bound (cfs) Geo. sig. flow bound as a percentage of 2-year forested 50% of 2- year forested discharge 8% of 2-year forested discharge WC-R01 30.7 51.3 167% 8.3 1.5 19% 4.13 0.66 WC-R02 30.7 56.1 183% 8.3 0.5 6% 4.13 0.66 WC-R03 22.7 65.6 289% 6.0 4.3 72% 3.02 0.48 WC-R04 22.7 42.0 185% 6.0 0.4 7% 3.02 0.48 WC-R05 22.7 38.5 169% 6.0 0.4 7% 3.02 0.48 WC-R06 19.5 35.0 180% 5.4 0.4 7% 2.71 0.43 WC-R07 19.5 35.0 180% 5.4 0.4 7% 2.71 0.43 WC-R08 19.5 32.9 169% 5.4 0.3 5% 2.71 0.43 WC-R09 19.5 32.9 169% 5.4 0.3 6% 2.71 0.43 WC-R10 14.8 26.6 180% 4.1 0.3 7% 2.06 0.33 WC-R11 14.8 26.6 180% 4.1 0.3 7% 2.06 0.33 WC-R12 14.8 26.6 180% 4.1 0.3 8% 2.06 0.33 ---PAGE BREAK--- Clarks Creek Sediment Reduction Action Plan Use of contents on this sheet is subject to the limitations specified at the end of this document. Clarks Creek Sediment Reduction Action Plan FINAL (v19).docx Appendix F: LID Design Concepts ---PAGE BREAK--- This page intentionally left blank. ---PAGE BREAK--- ---PAGE BREAK--- ---PAGE BREAK--- ---PAGE BREAK---