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Letter of Approval – GRAD 23-05 – Woodburn Apartments Page 1 of 3 August 17, 2023 AAI Engineering Christopher Thornton, PE 4875 SW Griffith Dr Suite 100 Beaverton, OR 97005 RE: Approval of Grading Permit GRAD 23-05 “Woodburn Apartments” for 119 N. Pacific Hwy (Tax Lot 051W17BC07500) Dear Mr. Thornton: Staff approves the Grading Permit, subject to the conditions of approval outlined in this letter. Summary of Review: This site is subject to the development standards of the Woodburn Development Ordinance (WDO). The applicant is requesting to perform grading work in preparation for construction of an apartment complex. Pursuant to WDO 4.01.02, the Director shall render all Type I land use decisions. The Director’s decision is the final decision of the City on a Type I application and cannot be appealed by any party through the City land use appeals process. Planning Conditions of Approval: 1. Conformance with Approved Plans: All site work shall be in substantial conformance with the approved grading plans. 2. DEQ: All development activity shall be in accordance with the approved Department of Environmental Quality (DEQ) 1200-C permit. The applicant shall provide to the City any modifications to the DEQ permit. 3. Other agencies: The applicant, not the City, is responsible for obtaining permits from Marion County, US Army Corps of Engineers (USACE), Oregon Department of State Lands (DSL), Oregon Department of Transportation (ODOT), and other agencies which might require approval or permit. ---PAGE BREAK--- Letter of Approval – GRAD 23-05 – Woodburn Apartments Page 2 of 3 4. ROW: All work within City rights-of-way (ROWs) or easements within City jurisdiction shall require plan approval and permit issuance from the Public Works Department. All work within ODOT rights-of-way (ROWs) or easements within ODOT jurisdiction shall require plan approval and permit issuance from ODOT. Public Works Conditions of Approval: 5. There is an issue with the private storm design that must be resolved prior to civil plan approval. This Grading Permit is approved prior to civil plan approval at owner’s own risk. 6. The applicant shall comply with the submitted grading and erosion control plans, including measures to keep the ROW clean, to protect existing catch basins around the work area, and maintain dust control measures. All catch basins around the work area shall be clean of debris and soils at all times. 7. Construction access is limited to only one construction entrance onto State Hwy 99E. 8. The applicant shall continuously maintain adequate protection of all work from damage and protect the public and private property of others from injury or loss arising in connection with the work. 9. The applicant shall comply with City of Woodburn Planning Department requirements through Woodburn Development Ordinance (WDO) 5.01.04 Grading Permit. 10. Prior to starting work, contact ODOT for inspection of the erosion control in their rights-of-way. 11. All work in the right-of-way will need to wait for a construction permit from ODOT. Once that permit is acquired, the applicant shall leave the ROW in clean condition, free from litter and debris, at the end of each workday, or more frequently if directed by the ODOT Inspector. 12. Sidewalk and street closures are not allowed under this permit. 13. Prior to starting work, silt fencing shall be installed around the entire perimeter of the work area. Applicant shall comply with all requirements and conditions set on their 1200C permit. ---PAGE BREAK--- Letter of Approval – GRAD 23-05 – Woodburn Apartments Page 3 of 3 Final decision approved by designee: Heidi Hinshaw August 17, 2023 Associate Planner Enclosures: • DEQ 1200-C Permit • Approved Plans • Stormwater Report & Calculations cc: Chris Kerr, Community Development Director Colin Cortes, AICP, CNU-A, Senior Planner Dan Handel, AICP, Planner Curtis Stultz, Public Works Director Dago Garcia, PE, City Engineer Casey Knecht, ODOT Region 2 file: GRAD 23-05 ---PAGE BREAK--- ---PAGE BREAK--- Department of Environmental Quality Water Quality Tina Kotek, Governor July 21, 2023 Abdulbaset Shagrun Woodburn Realestate, LLC 3000 Market St NE Ste 510 Salem, Oregon 97301-1807 Re: 1200-C National Pollutant Discharge Elimination System (NPDES) Registration Permit/PLC No.: NGEN12C-ORR10H830 Project Name: 119 Pacific Highway Project Location: 119 N Pacific Hwy, Woodburn, Marion County Dear Abdulbaset Shagrun: The Oregon Department of Environmental Quality (DEQ) has reviewed your application and approved your registration for coverage under the NPDES Construction Stormwater Discharge Permit 1200-C (permit). As the registrant, you are legally responsible for compliance with all permit conditions. See this link for a copy of the permit, technical assistance, and all relevant permit forms. Registrant Obligations • Comply with all permit conditions. DEQ strongly recommends that you read the permit. • Fully implement your Erosion and Sediment Control Plan (ESCP). You may need to modify site control measures as site conditions change. • Ensure that all appropriate contractors hired by you to implement the permit on your behalf have a copy of the ESCP and the permit. Keep a list of all contractors working on your site along with their contact information. • Notify DEQ of significant projects changes, including ESCP revisions, inspectors, or project ownership changes. • Perform & document visual monitoring according to Schedule B of the permit by a certified erosion and sediment control person. • Terminate coverage at the end of the project. You will be charged an annual registration fee until registration is terminated. The permit does not authorize excavation or fill in state waterways, including wetlands, and does not replace the requirement for receiving authorization to do this type of work under Section 404 of the Clean Water Act. If the authorized activity involves earthmoving in a known or suspected wetland condition you must contact the Department of State Lands at [PHONE REDACTED] if you are west of the Cascades, or 541- 388-6112 if you are east of the Cascades, and request a wetland determination prior to earth moving. The construction stormwater general permit, technical assistance manuals and other information is also available on DEQ Stormwater Program’s website. Sincerely, DEQ Stormwater Permitting Program ---PAGE BREAK--- UNION PACIFIC RAILROAD 4875 SW Griffith Drive I Suite 300 I Beaverton, OR I 97005 [PHONE REDACTED] tel I [PHONE REDACTED] fax I www.aaieng.com ’ ’ ’ SITE ---PAGE BREAK--- W UNION PACIFIC RAILROAD CLEVELAND STREET TAX LOT 7500 STATE HWY 99E TAX LOT 6800 D S S S S 4875 SW Griffith Drive I Suite 300 I Beaverton, OR I 97005 [PHONE REDACTED] tel I [PHONE REDACTED] fax I www.aaieng.com ---PAGE BREAK--- W TAX LOT 7500 TAX LOT 6800 D S S S S 4875 SW Griffith Drive I Suite 300 I Beaverton, OR I 97005 [PHONE REDACTED] tel I [PHONE REDACTED] fax I www.aaieng.com ---PAGE BREAK--- UNION PACIFIC RAILROAD CLEVELAND STREET STATE HWY 99E D 4875 SW Griffith Drive I Suite 300 I Beaverton, OR I 97005 [PHONE REDACTED] tel I [PHONE REDACTED] fax I www.aaieng.com ---PAGE BREAK--- 4875 SW Griffith Drive I Suite 300 I Beaverton, OR I 97005 [PHONE REDACTED] tel I [PHONE REDACTED] fax I www.aaieng.com ---PAGE BREAK--- D 4875 SW Griffith Drive I Suite 300 I Beaverton, OR I 97005 [PHONE REDACTED] tel I [PHONE REDACTED] fax I www.aaieng.com ---PAGE BREAK--- D 4875 SW Griffith Drive I Suite 300 I Beaverton, OR I 97005 [PHONE REDACTED] tel I [PHONE REDACTED] fax I www.aaieng.com ---PAGE BREAK--- 4875 SW Griffith Drive I Suite 300 I Beaverton, OR I 97005 [PHONE REDACTED] tel I [PHONE REDACTED] fax I www.aaieng.com ---PAGE BREAK--- Onsite Plans ---PAGE BREAK--- UNION PACIFIC RAILROAD STATE HWY 99E (ODOT HWY 1E/81) SW *ULIILWK DULYH _ _ %HDYHUWRQ OR _ WHO _ ID[ _ SITE ---PAGE BREAK--- 4875 SW Griffith Drive I Suite 300 I Beaverton, OR I 97005 [PHONE REDACTED] tel I [PHONE REDACTED] fax I www.aaieng.com ---PAGE BREAK--- W UNION PACIFIC RAILROAD CLEVELAND STREET TAX LOT 7500 STATE HWY 99E TAX LOT 6800 D S S S S 4875 SW Griffith Drive I Suite 300 I Beaverton, OR I 97005 [PHONE REDACTED] tel I [PHONE REDACTED] fax I www.aaieng.com R SURVEYING, LLC 2003 25TH STREET S.E. (503) 581-6362 SALEM, OREGON 97302 FAX(503) 581-0901 AZER SITE L ---PAGE BREAK--- W TAX LOT 7500 TAX LOT 6800 D S S S S 4875 SW Griffith Drive I Suite 300 I Beaverton, OR I 97005 [PHONE REDACTED] tel I [PHONE REDACTED] fax I www.aaieng.com ---PAGE BREAK--- W S S S S 4875 SW Griffith Drive I Suite 300 I Beaverton, OR I 97005 [PHONE REDACTED] tel I [PHONE REDACTED] fax I www.aaieng.com ---PAGE BREAK--- W D S S S S 4875 SW Griffith Drive I Suite 300 I Beaverton, OR I 97005 [PHONE REDACTED] tel I [PHONE REDACTED] fax I www.aaieng.com ---PAGE BREAK--- W UNION PACIFIC RAILROAD CLEVELAND STREET STATE HWY 99E D S S S S 4875 SW Griffith Drive I Suite 300 I Beaverton, OR I 97005 [PHONE REDACTED] tel I [PHONE REDACTED] fax I www.aaieng.com ---PAGE BREAK--- W UNION PACIFIC RAILROAD CLEVELAND STREET STATE HWY 99E D S S S S 4875 SW Griffith Drive I Suite 300 I Beaverton, OR I 97005 [PHONE REDACTED] tel I [PHONE REDACTED] fax I www.aaieng.com ---PAGE BREAK--- 4875 SW Griffith Drive I Suite 300 I Beaverton, OR I 97005 [PHONE REDACTED] tel I [PHONE REDACTED] fax I www.aaieng.com 5 C4.0 4 C4.0 ---PAGE BREAK--- 4875 SW Griffith Drive I Suite 300 I Beaverton, OR I 97005 [PHONE REDACTED] tel I [PHONE REDACTED] fax I www.aaieng.com WYE PLUGGED CROSS TEE BEND PLUGGED CROSS TEE PLUG OR CAP BEARING AREA OF THRUST BLOCK IN SQUARE FOOT UNPAVED AREAS PAVED AREAS PLAN SIDE SECTION PLAN SECTION SECTION SECTION A PLAN SHEAR GATE DETAILS ---PAGE BREAK--- 4875 SW Griffith Drive I Suite 300 I Beaverton, OR I 97005 [PHONE REDACTED] tel I [PHONE REDACTED] fax I www.aaieng.com ELEVATION PLAN METER SIDE CUSTOMER SIDE SECTION HARD SURFACE LANDSCAPE AREA ---PAGE BREAK--- 4875 SW Griffith Drive I Suite 300 I Beaverton, OR I 97005 [PHONE REDACTED] tel I [PHONE REDACTED] fax I www.aaieng.com ---PAGE BREAK--- Storm Report ---PAGE BREAK--- 119 N Pacific Hwy STORMWATER REPORT & CALCULATIONS Woodburn, Oregon 97071 Revised February 24, 2023 February 08 , 2022 PROJECT NUMBER: A21152.10 Christopher Thornton, PE AAI Engineering 4875 S.W. Griffith Drive Suite 100 Beaverton, Oregon PH [PHONE REDACTED] FX [PHONE REDACTED] EMAIL: [EMAIL REDACTED] ---PAGE BREAK--- 119 N Pacific Hwy Table of Contents I. Project Summary 1 II. Stormwater Design 1 III. Calculations 2 IV. Operations and Maintenance 2 V. Engineering Conclusion 2 Appendices Appendix A Existing Conditions Appendix B Site Plan Appendix C Storm Plan and Details Appendix D Stormwater Calculations Appendix E Operations and Maintenance ---PAGE BREAK--- 119 N Pacific Hwy 1 I. Project Summary This report has been prepared to outline the existing and proposed on-site stormwater conditions for the 119 N Pacific Hwy project. The report is based off topographic survey and field observation. The project is located at 119 N Pacific Hwy in Woodburn, Oregon. The total pre-developed site is approximately 1.38 acres. The site currently consists of an open field with gravel and dispersed vegetation, and is relatively flat. See Appendix A – Existing Conditions The primary purpose of this project is to develop the site for a new building with driveways, pedestrian connection and associated utilities. In addition to the site improvements, stormwater management will be provided, including conveyance and flow control. See Appendix B – Site Plan and Appendix C – Storm Plan and Details. II. Stormwater Design At the time of writing, additional information regarding the existing storm connection point is forthcoming. As such, the onsite storm system has been conservatively designed with respect to the available depth to invert at the site’s outfall connection point. The proposed stormwater facilities are designed to capture, convey, and detain runoff from the proposed site improvements. No runoff from adjacent properties is anticipated to be captured by the proposed facilities. In addition, site impervious runoff will be completely managed on site and will not drain onto adjacent private properties. The stormwater runoff from the roof area will be directed into downspouts and be conveyed to the detention system by underground piping. Stormwater runoff from pavement, parking, and sidewalk areas will sheet flow into sumped and trapped catch basins and be similarly conveyed to the onsite detention system. Per Table 7-1 of the City of Woodburn Stormwater Drainage Master Plan, a 10-acre site needs to provided a minimum of 18,883 cubic feet of storage. The proposed site area is 1.38 acres. By proportionality, a minimum of 2,605 cubic feet of storage must be provided for this site. The use of an underground chamber storage facility is proposed to provide 3,542 cubic feet of storage. The proposed detention volume meets those required by Table 7-1. A copy of this table has been provided in Appendix D - Stormwater Calculations. Per the City’s Stormwater Drainage Master Plan Runoff Detention Requirement, flow control for the onsite detention must limit the post-development 25-year outflow to no more than the 5-year ---PAGE BREAK--- 119 N Pacific Hwy 2 undeveloped site peak runoff. With the use of a flow control manhole in conjunction with the proposed detention system, the site is designed to meet this requirement. See Appendix D – Storm Calculations, Appendix E – HydroCAD Report, and Appendix F – Geotech Report III. Calculations HydroCAD has been used to verify detention sizing and to design the flow control orifices at the site’s outfall, following the storm intensities and durations outlined in Table 7-1 of the City of Woodburn Stormwater Drainage Master Plan. Conveyance calculations have been completed using Manning’s Equation for pipe flow, utilizing the appropriate ODOT IDF Curve for the lowest duration 25-year storm. A copy of the IDF curve used has been included in this report. See Appendix D – Stormwater Calculations IV. Operations and Maintenance See Appendix E – Operations and Maintenance for O&M requirements. V. Engineering Conclusion Based on the requirements of the City of Woodburn Management Manual, the proposed site facilities will be adequately designed to manage the proposed development. ---PAGE BREAK--- 119 N Pacific Hwy A Appendix A Existing Conditions ---PAGE BREAK--- W UNION PACIFIC RAILROAD CLEVELAND STREET TAX LOT 7500 STATE HWY 99E TAX LOT 6800 D S S S S 4875 SW Griffith Drive I Suite 300 I Beaverton, OR I 97005 [PHONE REDACTED] tel I [PHONE REDACTED] fax I www.aaieng.com R SURVEYING, LLC 2003 25TH STREET S.E. (503) 581-6362 SALEM, OREGON 97302 FAX(503) 581-0901 AZER SITE L ---PAGE BREAK--- 119 N Pacific Hwy B Appendix B Site Plan ---PAGE BREAK--- W S S S S 4875 SW Griffith Drive I Suite 300 I Beaverton, OR I 97005 [PHONE REDACTED] tel I [PHONE REDACTED] fax I www.aaieng.com ---PAGE BREAK--- 119 N Pacific Hwy C Appendix C Storm Plan and Details ---PAGE BREAK--- W W W W W UNION PACIFIC RAILROAD CLEVELAND STREET STATE HWY 99E S S S S 4875 SW Griffith Drive I Suite 300 I Beaverton, OR I 97005 [PHONE REDACTED] tel I [PHONE REDACTED] fax I www.aaieng.com ---PAGE BREAK--- W UNION PACIFIC RAILROAD CLEVELAND STREET STATE HWY 99E D S S S S 4875 SW Griffith Drive I Suite 300 I Beaverton, OR I 97005 [PHONE REDACTED] tel I [PHONE REDACTED] fax I www.aaieng.com ---PAGE BREAK--- 4875 SW Griffith Drive I Suite 300 I Beaverton, OR I 97005 [PHONE REDACTED] tel I [PHONE REDACTED] fax I www.aaieng.com WYE PLUGGED CROSS TEE BEND PLUGGED CROSS TEE PLUG OR CAP BEARING AREA OF THRUST BLOCK IN SQUARE FOOT UNPAVED AREAS PAVED AREAS PLAN SIDE SECTION PLAN SECTION SECTION SECTION A PLAN SHEAR GATE DETAILS ---PAGE BREAK--- 4875 SW Griffith Drive I Suite 300 I Beaverton, OR I 97005 [PHONE REDACTED] tel I [PHONE REDACTED] fax I www.aaieng.com ELEVATION PLAN METER SIDE CUSTOMER SIDE SECTION HARD SURFACE LANDSCAPE AREA ---PAGE BREAK--- 4875 SW Griffith Drive I Suite 300 I Beaverton, OR I 97005 [PHONE REDACTED] tel I [PHONE REDACTED] fax I www.aaieng.com ---PAGE BREAK--- 119 N Pacific Hwy D Appendix D Stormwater Calculations ---PAGE BREAK--- Approved by Woodburn City Council 12/9/96 Storms Results (Rates) 100 yr. 1.26" 2.7 hrs 50 yr. 1.20" 2.76 hrs 25yr. 1.14" 2.86 hrs 10yr. 1.08" 2.97 hrs 5 yr. 0.935" 3.28 hrs 2yr. 0.800" 3.64 hrs CITY OF WOODBURN Table 7- 1 VOLUMES FOR DIFFERENT INTENSITY STORMS FOR 10-ACRE SITE i A = 435,600 Developed Volumes =10 acres c = 0.71 Sec storms (lNTENSlHES) (UN)developed c = 0.25 (cis) 0.467 in 435,600 lf3 0.71 3.313 32,2051f3 hr or 10 acres 0.25 1.167 11,340 lf3 0.435in 435,600112 0.71 3.087 30,6721f3 hr or 10 acres 0.25 1.087 10,800 lf3 0.399 in 435,600 lf3 0.71 2.830 29, 1381f3 hr or 10 acres 0.25 0.996 10,2551f3 0.364 in 435,60011' 0.71 2.582 27,6051f3 hr or 10 acres 0.25 0.909 9,720 lf3 0.2851!! 435,600112 0.71 2.024 23,8991f3 hr or 10 acres 0.25 0.713 8,4151f3 (320 gpm) 0.220in 435,600 fl2 0.71 1.560 20,4481f3 hr or 10 acres 0.25 0.549 7,200 lf3 RUN OFF DETENTION REQUIREMENT lf3 3600sec hrs sec hrs storm 32,2051f3 11 .340 lf3 20,8651f3 storage volume 30,6721f3 10,800 lf3 19,8721f3 storage volume 29, 1381f3 10.2551f3 18,8831f3 storage volume 27,6051f3 9.720 lf3 17,8851f3 storage volume 23,8991f3 8.4151f3 15,4841f3 storage volume 20,4481f3 7,200 lf3 13,2481f3 storage volume 1) Construct a device that has capacity for detaining difference in nm off volume received by undeveloped and developed land for a 25-year storm. 2) Construct a discharge orifice ora size that the quantity or run off through the orifice is equal to run off flow from a storm of5-year or less, undeveloped land. 3) Construct a detention facility to have a post-development 25-year capacity with a discharge orifice (or structure) sil.ed to limit outflow to no more than the tmdeveloped site peak run off for the existing (undeveloped) 5 year frequency storm Detention volumes calculated by the following methods arc acceptable: A. Santa Barbara Urban Hydrograph routing model (as prescribed by the King County Surface Water Design Manual) for the post development 25-year runoff hydrograph detained back to the existing 5 year peak site discharge. B. 18,883 CF/10 Acre drainage area as per City of Woodburn standard table, above, based on the rational method. SAFETY REQUIREMENTS 1) Depth ofstonn water within 30 feet from the edge of detention ponds, if open to pubUc, shall be limited to 3 feet, then gradualslope(3%)to higher depth shall be allowed. Maximum pond side slopes shall be 3' horizontal to 1' vertical, however, gentler slope is desirable. REV. A updated 08/30/96 Item #3 added 12/9/96 Safety Item revised. REV. B. APPROVED BY CITY COUNClL 12/9/96 ---PAGE BREAK--- 1S Post Developed 2S Undeveloped 1P SC-310 Chambers Routing Diagram for 119 N Pacific Hwy Woodburn Prepared by {enter your company name here}, Printed 2/27/2023 HydroCAD® 10.00-26 s/n 01638 © 2020 HydroCAD Software Solutions LLC Subcat Reach Pond Link ---PAGE BREAK--- 119 N Pacific Hwy Woodburn Printed 2/27/2023 Prepared by {enter your company name here} Page 2 HydroCAD® 10.00-26 s/n 01638 © 2020 HydroCAD Software Solutions LLC Project Notes Rainfall events imported from "17043 Curtis Trailer Hydrocad.hcp" ---PAGE BREAK--- 119 N Pacific Hwy Woodburn Printed 2/27/2023 Prepared by {enter your company name here} Page 3 HydroCAD® 10.00-26 s/n 01638 © 2020 HydroCAD Software Solutions LLC Area Listing (all nodes) Area (acres) CN Description (subcatchment-numbers) 0.128 79 50-75% Grass cover, Fair, HSG C (1S) 1.259 86 <50% Grass cover, Poor, HSG C (2S) 1.131 98 Paved parking, Concrete, Roof (1S) 2.519 91 TOTAL AREA ---PAGE BREAK--- 119 N Pacific Hwy Woodburn Printed 2/27/2023 Prepared by {enter your company name here} Page 4 HydroCAD® 10.00-26 s/n 01638 © 2020 HydroCAD Software Solutions LLC Soil Listing (all nodes) Area (acres) Soil Group Subcatchment Numbers 0.000 HSG A 0.000 HSG B 1.388 HSG C 1S, 2S 0.000 HSG D 1.131 Other 1S 2.519 TOTAL AREA ---PAGE BREAK--- 119 N Pacific Hwy Woodburn Printed 2/27/2023 Prepared by {enter your company name here} Page 5 HydroCAD® 10.00-26 s/n 01638 © 2020 HydroCAD Software Solutions LLC Ground Covers (all nodes) HSG-A (acres) HSG-B (acres) HSG-C (acres) HSG-D (acres) Other (acres) Total (acres) Ground Cover Subcatchment Numbers 0.000 0.000 0.128 0.000 0.000 0.128 50-75% Grass cover, Fair 1S 0.000 0.000 1.259 0.000 0.000 1.259 <50% Grass cover, Poor 2S 0.000 0.000 0.000 0.000 1.131 1.131 Paved parking, Concrete, Roof 1S 0.000 0.000 1.388 0.000 1.131 2.519 TOTAL AREA ---PAGE BREAK--- Type IA 24-hr 3.28 hrs 5 yr Rainfall=0.94" 119 N Pacific Hwy Woodburn Printed 2/27/2023 Prepared by {enter your company name here} Page 6 HydroCAD® 10.00-26 s/n 01638 © 2020 HydroCAD Software Solutions LLC Time span=0.00-50.00 hrs, dt=0.05 hrs, 1001 points Runoff by SBUH method, Split Pervious/Imperv. Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=54,860 sf 89.80% Impervious Runoff Depth=0.66" Subcatchment 1S: Post Developed Tc=5.0 min CN=79/98 Runoff=0.99 cfs 0.070 af Runoff Area=54,860 sf 0.00% Impervious Runoff Depth=0.17" Subcatchment 2S: Undeveloped Tc=5.0 min CN=86/0 Runoff=0.10 cfs 0.018 af Peak Elev=1.35' Storage=2,448 cf Inflow=0.99 cfs 0.070 af Pond 1P: SC-310 Chambers Outflow=0.08 cfs 0.070 af Total Runoff Area = 2.519 ac Runoff Volume = 0.087 af Average Runoff Depth = 0.42" 55.10% Pervious = 1.388 ac 44.90% Impervious = 1.131 ac ---PAGE BREAK--- Type IA 24-hr 3.28 hrs 5 yr Rainfall=0.94" 119 N Pacific Hwy Woodburn Printed 2/27/2023 Prepared by {enter your company name here} Page 7 HydroCAD® 10.00-26 s/n 01638 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: Post Developed [49] Hint: Tc<2dt may require smaller dt Runoff = 0.99 cfs @ 1.15 hrs, Volume= 0.070 af, Depth= 0.66" Runoff by SBUH method, Split Pervious/Imperv., Time Span= 0.00-50.00 hrs, dt= 0.05 hrs Type IA 24-hr 3.28 hrs 5 yr Rainfall=0.94" Area (sf) CN Description * 49,266 98 Paved parking, Concrete, Roof 5,594 79 50-75% Grass cover, Fair, HSG C 54,860 96 Weighted Average 5,594 79 10.20% Pervious Area 49,266 98 89.80% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 1S: Post Developed Runoff Hydrograph Time (hours) 50 48 46 44 42 40 38 36 34 32 30 28 26 24 22 20 18 16 14 12 10 8 6 4 2 0 Flow (cfs) 1 0 Type IA 24-hr 3.28 hrs 5 yr Rainfall=0.94" Runoff Area=54,860 sf Runoff Volume=0.070 af Runoff Depth=0.66" Tc=5.0 min CN=79/98 0.99 cfs ---PAGE BREAK--- Type IA 24-hr 3.28 hrs 5 yr Rainfall=0.94" 119 N Pacific Hwy Woodburn Printed 2/27/2023 Prepared by {enter your company name here} Page 8 HydroCAD® 10.00-26 s/n 01638 © 2020 HydroCAD Software Solutions LLC Hydrograph for Subcatchment 1S: Post Developed Time (hours) Precip. (inches) Perv.Excess (inches) Imp.Excess (inches) Runoff (cfs) 0.00 0.00 0.00 0.00 0.00 1.00 0.28 0.00 0.13 0.36 2.00 0.71 0.01 0.51 0.26 3.00 0.90 0.05 0.70 0.18 4.00 0.94 0.05 0.73 0.00 5.00 0.94 0.05 0.73 0.00 6.00 0.94 0.05 0.73 0.00 7.00 0.94 0.05 0.73 0.00 8.00 0.94 0.05 0.73 0.00 9.00 0.94 0.05 0.73 0.00 10.00 0.94 0.05 0.73 0.00 11.00 0.94 0.05 0.73 0.00 12.00 0.94 0.05 0.73 0.00 13.00 0.94 0.05 0.73 0.00 14.00 0.94 0.05 0.73 0.00 15.00 0.94 0.05 0.73 0.00 16.00 0.94 0.05 0.73 0.00 17.00 0.94 0.05 0.73 0.00 18.00 0.94 0.05 0.73 0.00 19.00 0.94 0.05 0.73 0.00 20.00 0.94 0.05 0.73 0.00 21.00 0.94 0.05 0.73 0.00 22.00 0.94 0.05 0.73 0.00 23.00 0.94 0.05 0.73 0.00 24.00 0.94 0.05 0.73 0.00 25.00 0.94 0.05 0.73 0.00 26.00 0.94 0.05 0.73 0.00 27.00 0.94 0.05 0.73 0.00 28.00 0.94 0.05 0.73 0.00 29.00 0.94 0.05 0.73 0.00 30.00 0.94 0.05 0.73 0.00 31.00 0.94 0.05 0.73 0.00 32.00 0.94 0.05 0.73 0.00 33.00 0.94 0.05 0.73 0.00 34.00 0.94 0.05 0.73 0.00 35.00 0.94 0.05 0.73 0.00 36.00 0.94 0.05 0.73 0.00 37.00 0.94 0.05 0.73 0.00 38.00 0.94 0.05 0.73 0.00 39.00 0.94 0.05 0.73 0.00 40.00 0.94 0.05 0.73 0.00 41.00 0.94 0.05 0.73 0.00 42.00 0.94 0.05 0.73 0.00 43.00 0.94 0.05 0.73 0.00 44.00 0.94 0.05 0.73 0.00 45.00 0.94 0.05 0.73 0.00 46.00 0.94 0.05 0.73 0.00 47.00 0.94 0.05 0.73 0.00 48.00 0.94 0.05 0.73 0.00 49.00 0.94 0.05 0.73 0.00 50.00 0.94 0.05 0.73 0.00 ---PAGE BREAK--- Type IA 24-hr 3.28 hrs 5 yr Rainfall=0.94" 119 N Pacific Hwy Woodburn Printed 2/27/2023 Prepared by {enter your company name here} Page 9 HydroCAD® 10.00-26 s/n 01638 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 2S: Undeveloped [49] Hint: Tc<2dt may require smaller dt Runoff = 0.10 cfs @ 2.28 hrs, Volume= 0.018 af, Depth= 0.17" Runoff by SBUH method, Split Pervious/Imperv., Time Span= 0.00-50.00 hrs, dt= 0.05 hrs Type IA 24-hr 3.28 hrs 5 yr Rainfall=0.94" Area (sf) CN Description 54,860 86 <50% Grass cover, Poor, HSG C 54,860 86 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 2S: Undeveloped Runoff Hydrograph Time (hours) 50 48 46 44 42 40 38 36 34 32 30 28 26 24 22 20 18 16 14 12 10 8 6 4 2 0 Flow (cfs) 0.11 0.105 0.1 0.095 0.09 0.085 0.08 0.075 0.07 0.065 0.06 0.055 0.05 0.045 0.04 0.035 0.03 0.025 0.02 0.015 0.01 0.005 0 Type IA 24-hr 3.28 hrs 5 yr Rainfall=0.94" Runoff Area=54,860 sf Runoff Volume=0.018 af Runoff Depth=0.17" Tc=5.0 min CN=86/0 0.10 cfs ---PAGE BREAK--- Type IA 24-hr 3.28 hrs 5 yr Rainfall=0.94" 119 N Pacific Hwy Woodburn Printed 2/27/2023 Prepared by {enter your company name here} Page 10 HydroCAD® 10.00-26 s/n 01638 © 2020 HydroCAD Software Solutions LLC Hydrograph for Subcatchment 2S: Undeveloped Time (hours) Precip. (inches) Perv.Excess (inches) Imp.Excess (inches) Runoff (cfs) 0.00 0.00 0.00 0.00 0.00 1.00 0.28 0.00 0.00 0.00 2.00 0.71 0.07 0.00 0.10 3.00 0.90 0.15 0.00 0.09 4.00 0.94 0.17 0.00 0.00 5.00 0.94 0.17 0.00 0.00 6.00 0.94 0.17 0.00 0.00 7.00 0.94 0.17 0.00 0.00 8.00 0.94 0.17 0.00 0.00 9.00 0.94 0.17 0.00 0.00 10.00 0.94 0.17 0.00 0.00 11.00 0.94 0.17 0.00 0.00 12.00 0.94 0.17 0.00 0.00 13.00 0.94 0.17 0.00 0.00 14.00 0.94 0.17 0.00 0.00 15.00 0.94 0.17 0.00 0.00 16.00 0.94 0.17 0.00 0.00 17.00 0.94 0.17 0.00 0.00 18.00 0.94 0.17 0.00 0.00 19.00 0.94 0.17 0.00 0.00 20.00 0.94 0.17 0.00 0.00 21.00 0.94 0.17 0.00 0.00 22.00 0.94 0.17 0.00 0.00 23.00 0.94 0.17 0.00 0.00 24.00 0.94 0.17 0.00 0.00 25.00 0.94 0.17 0.00 0.00 26.00 0.94 0.17 0.00 0.00 27.00 0.94 0.17 0.00 0.00 28.00 0.94 0.17 0.00 0.00 29.00 0.94 0.17 0.00 0.00 30.00 0.94 0.17 0.00 0.00 31.00 0.94 0.17 0.00 0.00 32.00 0.94 0.17 0.00 0.00 33.00 0.94 0.17 0.00 0.00 34.00 0.94 0.17 0.00 0.00 35.00 0.94 0.17 0.00 0.00 36.00 0.94 0.17 0.00 0.00 37.00 0.94 0.17 0.00 0.00 38.00 0.94 0.17 0.00 0.00 39.00 0.94 0.17 0.00 0.00 40.00 0.94 0.17 0.00 0.00 41.00 0.94 0.17 0.00 0.00 42.00 0.94 0.17 0.00 0.00 43.00 0.94 0.17 0.00 0.00 44.00 0.94 0.17 0.00 0.00 45.00 0.94 0.17 0.00 0.00 46.00 0.94 0.17 0.00 0.00 47.00 0.94 0.17 0.00 0.00 48.00 0.94 0.17 0.00 0.00 49.00 0.94 0.17 0.00 0.00 50.00 0.94 0.17 0.00 0.00 ---PAGE BREAK--- Type IA 24-hr 3.28 hrs 5 yr Rainfall=0.94" 119 N Pacific Hwy Woodburn Printed 2/27/2023 Prepared by {enter your company name here} Page 11 HydroCAD® 10.00-26 s/n 01638 © 2020 HydroCAD Software Solutions LLC Summary for Pond 1P: SC-310 Chambers Inflow Area = 1.259 ac, 89.80% Impervious, Inflow Depth = 0.66" for 5 yr event Inflow = 0.99 cfs @ 1.15 hrs, Volume= 0.070 af Outflow = 0.08 cfs @ 3.37 hrs, Volume= 0.070 af, Atten= 92%, Lag= 133.3 min Primary = 0.08 cfs @ 3.37 hrs, Volume= 0.070 af Routing by Stor-Ind method, Time Span= 0.00-50.00 hrs, dt= 0.05 hrs / 2 Peak Elev= 1.35' @ 3.37 hrs Surf.Area= 2,775 sf Storage= 2,448 cf Plug-Flow detention time= 392.4 min calculated for 0.070 af (100% of inflow) Center-of-Mass det. time= 391.9 min ( 495.9 - 104.1 ) Volume Invert Avail.Storage Storage Description #1 0.00' 1,949 cf Custom Stage Data (Prismatic) Listed below (Recalc) 6,466 cf Overall - 1,592 cf Embedded = 4,874 cf x 40.0% Voids #2 0.00' 1,592 cf ADS_StormTech SC-310 +Cap x 108 Inside #1 Effective Size= 28.9"W x 16.0"H 2.07 sf x 7.12'L = 14.7 cf Overall Size= 34.0"W x 16.0"H x 7.56'L with 0.44' Overlap 108 Chambers in 10 Rows 3,542 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 0.00 2,775 0 0 2.33 2,775 6,466 6,466 Device Routing Invert Outlet Devices #1 Primary 0.00' 1.6" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads #2 Primary 2.12' 18.0" Vert. Orifice/Grate C= 0.600 Primary OutFlow Max=0.08 cfs @ 3.37 hrs HW=1.34' (Free Discharge) 1=Orifice/Grate (Orifice Controls 0.08 cfs @ 5.58 fps) 2=Orifice/Grate ( Controls 0.00 cfs) ---PAGE BREAK--- Type IA 24-hr 3.28 hrs 5 yr Rainfall=0.94" 119 N Pacific Hwy Woodburn Printed 2/27/2023 Prepared by {enter your company name here} Page 12 HydroCAD® 10.00-26 s/n 01638 © 2020 HydroCAD Software Solutions LLC Pond 1P: SC-310 Chambers Inflow Primary Hydrograph Time (hours) 50 48 46 44 42 40 38 36 34 32 30 28 26 24 22 20 18 16 14 12 10 8 6 4 2 0 Flow (cfs) 1 0 Inflow Area=1.259 ac Peak Elev=1.35' Storage=2,448 cf 0.99 cfs 0.08 cfs Pond 1P: SC-310 Chambers Primary Stage-Discharge Discharge (cfs) 7 6 5 4 3 2 1 0 Elevation (feet) 3 2 1 0 Orifice/Grate Orifice/Grate ---PAGE BREAK--- Type IA 24-hr 3.28 hrs 5 yr Rainfall=0.94" 119 N Pacific Hwy Woodburn Printed 2/27/2023 Prepared by {enter your company name here} Page 13 HydroCAD® 10.00-26 s/n 01638 © 2020 HydroCAD Software Solutions LLC Pond 1P: SC-310 Chambers Storage Stage-Area-Storage Storage (cubic-feet) 3,500 3,000 2,500 2,000 1,500 1,000 500 0 Elevation (feet) 3 2 1 0 Custom Stage Data + ADS_StormTech SC-310 +Cap ---PAGE BREAK--- Type IA 24-hr 3.28 hrs 5 yr Rainfall=0.94" 119 N Pacific Hwy Woodburn Printed 2/27/2023 Prepared by {enter your company name here} Page 14 HydroCAD® 10.00-26 s/n 01638 © 2020 HydroCAD Software Solutions LLC Hydrograph for Pond 1P: SC-310 Chambers Time (hours) Inflow (cfs) Storage (cubic-feet) Elevation (feet) Primary (cfs) 0.00 0.00 0 0.00 0.00 1.00 0.36 339 0.15 0.03 2.00 0.26 1,808 0.89 0.06 3.00 0.18 2,344 1.25 0.08 4.00 0.00 2,298 1.22 0.07 5.00 0.00 2,042 1.03 0.07 6.00 0.00 1,806 0.89 0.06 7.00 0.00 1,586 0.76 0.06 8.00 0.00 1,383 0.66 0.05 9.00 0.00 1,194 0.56 0.05 10.00 0.00 1,020 0.47 0.05 11.00 0.00 861 0.40 0.04 12.00 0.00 715 0.33 0.04 13.00 0.00 584 0.27 0.03 14.00 0.00 466 0.21 0.03 15.00 0.00 361 0.16 0.03 16.00 0.00 270 0.12 0.02 17.00 0.00 192 0.09 0.02 18.00 0.00 129 0.06 0.01 19.00 0.00 85 0.04 0.01 20.00 0.00 56 0.03 0.01 21.00 0.00 37 0.02 0.00 22.00 0.00 24 0.01 0.00 23.00 0.00 16 0.01 0.00 24.00 0.00 10 0.00 0.00 25.00 0.00 7 0.00 0.00 26.00 0.00 4 0.00 0.00 27.00 0.00 3 0.00 0.00 28.00 0.00 2 0.00 0.00 29.00 0.00 1 0.00 0.00 30.00 0.00 1 0.00 0.00 31.00 0.00 1 0.00 0.00 32.00 0.00 0 0.00 0.00 33.00 0.00 0 0.00 0.00 34.00 0.00 0 0.00 0.00 35.00 0.00 0 0.00 0.00 36.00 0.00 0 0.00 0.00 37.00 0.00 0 0.00 0.00 38.00 0.00 0 0.00 0.00 39.00 0.00 0 0.00 0.00 40.00 0.00 0 0.00 0.00 41.00 0.00 0 0.00 0.00 42.00 0.00 0 0.00 0.00 43.00 0.00 0 0.00 0.00 44.00 0.00 0 0.00 0.00 45.00 0.00 0 0.00 0.00 46.00 0.00 0 0.00 0.00 47.00 0.00 0 0.00 0.00 48.00 0.00 0 0.00 0.00 49.00 0.00 0 0.00 0.00 50.00 0.00 0 0.00 0.00 ---PAGE BREAK--- Type IA 24-hr 3.28 hrs 5 yr Rainfall=0.94" 119 N Pacific Hwy Woodburn Printed 2/27/2023 Prepared by {enter your company name here} Page 15 HydroCAD® 10.00-26 s/n 01638 © 2020 HydroCAD Software Solutions LLC Stage-Discharge for Pond 1P: SC-310 Chambers Elevation (feet) Primary (cfs) 0.00 0.00 0.02 0.00 0.04 0.01 0.06 0.02 0.08 0.02 0.10 0.02 0.12 0.02 0.14 0.03 0.16 0.03 0.18 0.03 0.20 0.03 0.22 0.03 0.24 0.03 0.26 0.03 0.28 0.04 0.30 0.04 0.32 0.04 0.34 0.04 0.36 0.04 0.38 0.04 0.40 0.04 0.42 0.04 0.44 0.04 0.46 0.05 0.48 0.05 0.50 0.05 0.52 0.05 0.54 0.05 0.56 0.05 0.58 0.05 0.60 0.05 0.62 0.05 0.64 0.05 0.66 0.05 0.68 0.06 0.70 0.06 0.72 0.06 0.74 0.06 0.76 0.06 0.78 0.06 0.80 0.06 0.82 0.06 0.84 0.06 0.86 0.06 0.88 0.06 0.90 0.06 0.92 0.06 0.94 0.07 0.96 0.07 0.98 0.07 1.00 0.07 1.02 0.07 Elevation (feet) Primary (cfs) 1.04 0.07 1.06 0.07 1.08 0.07 1.10 0.07 1.12 0.07 1.14 0.07 1.16 0.07 1.18 0.07 1.20 0.07 1.22 0.07 1.24 0.07 1.26 0.08 1.28 0.08 1.30 0.08 1.32 0.08 1.34 0.08 1.36 0.08 1.38 0.08 1.40 0.08 1.42 0.08 1.44 0.08 1.46 0.08 1.48 0.08 1.50 0.08 1.52 0.08 1.54 0.08 1.56 0.08 1.58 0.08 1.60 0.09 1.62 0.09 1.64 0.09 1.66 0.09 1.68 0.09 1.70 0.09 1.72 0.09 1.74 0.09 1.76 0.09 1.78 0.09 1.80 0.09 1.82 0.09 1.84 0.09 1.86 0.09 1.88 0.09 1.90 0.09 1.92 0.09 1.94 0.09 1.96 0.09 1.98 0.09 2.00 0.10 2.02 0.10 2.04 0.10 2.06 0.10 Elevation (feet) Primary (cfs) 2.08 0.10 2.10 0.10 2.12 0.10 2.14 0.10 2.16 0.11 2.18 0.12 2.20 0.13 2.22 0.15 2.24 0.18 2.26 0.21 2.28 0.24 2.30 0.28 2.32 0.32 2.34 0.36 2.36 0.41 2.38 0.46 2.40 0.51 2.42 0.57 2.44 0.64 2.46 0.70 2.48 0.77 2.50 0.85 2.52 0.92 2.54 1.00 2.56 1.08 2.58 1.17 2.60 1.26 2.62 1.35 2.64 1.44 2.66 1.54 2.68 1.64 2.70 1.75 2.72 1.85 2.74 1.96 2.76 2.07 2.78 2.18 2.80 2.30 2.82 2.42 2.84 2.54 2.86 2.66 2.88 2.78 2.90 2.91 2.92 3.03 2.94 3.16 2.96 3.29 2.98 3.42 3.00 3.56 3.02 3.69 3.04 3.83 3.06 3.96 3.08 4.10 3.10 4.24 Elevation (feet) Primary (cfs) 3.12 4.38 3.14 4.52 3.16 4.66 3.18 4.80 3.20 4.94 3.22 5.08 3.24 5.22 3.26 5.36 3.28 5.50 3.30 5.64 3.32 5.77 3.34 5.91 3.36 6.05 3.38 6.18 3.40 6.31 3.42 6.44 3.44 6.57 3.46 6.69 3.48 6.81 3.50 6.93 3.52 7.04 3.54 7.15 3.56 7.25 3.58 7.34 3.60 7.43 3.62 7.50 ---PAGE BREAK--- Type IA 24-hr 3.28 hrs 5 yr Rainfall=0.94" 119 N Pacific Hwy Woodburn Printed 2/27/2023 Prepared by {enter your company name here} Page 16 HydroCAD® 10.00-26 s/n 01638 © 2020 HydroCAD Software Solutions LLC Stage-Area-Storage for Pond 1P: SC-310 Chambers Elevation (feet) Storage (cubic-feet) 0.00 0 0.05 111 0.10 222 0.15 332 0.20 441 0.25 549 0.30 656 0.35 762 0.40 867 0.45 971 0.50 1,073 0.55 1,174 0.60 1,274 0.65 1,372 0.70 1,468 0.75 1,562 0.80 1,654 0.85 1,744 0.90 1,832 0.95 1,916 1.00 1,998 1.05 2,075 1.10 2,147 1.15 2,215 1.20 2,278 1.25 2,339 1.30 2,398 1.35 2,454 1.40 2,509 1.45 2,565 1.50 2,620 1.55 2,676 1.60 2,731 1.65 2,787 1.70 2,842 1.75 2,898 1.80 2,953 1.85 3,009 1.90 3,064 1.95 3,120 2.00 3,175 2.05 3,231 2.10 3,286 2.15 3,342 2.20 3,397 2.25 3,453 2.30 3,508 2.35 3,542 2.40 3,542 2.45 3,542 2.50 3,542 2.55 3,542 Elevation (feet) Storage (cubic-feet) 2.60 3,542 2.65 3,542 2.70 3,542 2.75 3,542 2.80 3,542 2.85 3,542 2.90 3,542 2.95 3,542 3.00 3,542 3.05 3,542 3.10 3,542 3.15 3,542 3.20 3,542 3.25 3,542 3.30 3,542 3.35 3,542 3.40 3,542 3.45 3,542 3.50 3,542 3.55 3,542 3.60 3,542 ---PAGE BREAK--- Type IA 24-hr 2.86 hrs 25 yr Rainfall=1.14" 119 N Pacific Hwy Woodburn Printed 2/27/2023 Prepared by {enter your company name here} Page 17 HydroCAD® 10.00-26 s/n 01638 © 2020 HydroCAD Software Solutions LLC Time span=0.00-50.00 hrs, dt=0.05 hrs, 1001 points Runoff by SBUH method, Split Pervious/Imperv. Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=54,860 sf 89.80% Impervious Runoff Depth=0.84" Subcatchment 1S: Post Developed Tc=5.0 min CN=79/98 Runoff=1.38 cfs 0.089 af Runoff Area=54,860 sf 0.00% Impervious Runoff Depth=0.27" Subcatchment 2S: Undeveloped Tc=5.0 min CN=86/0 Runoff=0.22 cfs 0.029 af Peak Elev=2.05' Storage=3,229 cf Inflow=1.38 cfs 0.089 af Pond 1P: SC-310 Chambers Outflow=0.10 cfs 0.089 af Total Runoff Area = 2.519 ac Runoff Volume = 0.117 af Average Runoff Depth = 0.56" 55.10% Pervious = 1.388 ac 44.90% Impervious = 1.131 ac ---PAGE BREAK--- Type IA 24-hr 2.86 hrs 25 yr Rainfall=1.14" 119 N Pacific Hwy Woodburn Printed 2/27/2023 Prepared by {enter your company name here} Page 18 HydroCAD® 10.00-26 s/n 01638 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: Post Developed [49] Hint: Tc<2dt may require smaller dt Runoff = 1.38 cfs @ 1.01 hrs, Volume= 0.089 af, Depth= 0.84" Runoff by SBUH method, Split Pervious/Imperv., Time Span= 0.00-50.00 hrs, dt= 0.05 hrs Type IA 24-hr 2.86 hrs 25 yr Rainfall=1.14" Area (sf) CN Description * 49,266 98 Paved parking, Concrete, Roof 5,594 79 50-75% Grass cover, Fair, HSG C 54,860 96 Weighted Average 5,594 79 10.20% Pervious Area 49,266 98 89.80% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 1S: Post Developed Runoff Hydrograph Time (hours) 50 48 46 44 42 40 38 36 34 32 30 28 26 24 22 20 18 16 14 12 10 8 6 4 2 0 Flow (cfs) 1 0 Type IA 24-hr 2.86 hrs 25 yr Rainfall=1.14" Runoff Area=54,860 sf Runoff Volume=0.089 af Runoff Depth=0.84" Tc=5.0 min CN=79/98 1.38 cfs ---PAGE BREAK--- Type IA 24-hr 2.86 hrs 25 yr Rainfall=1.14" 119 N Pacific Hwy Woodburn Printed 2/27/2023 Prepared by {enter your company name here} Page 19 HydroCAD® 10.00-26 s/n 01638 © 2020 HydroCAD Software Solutions LLC Hydrograph for Subcatchment 1S: Post Developed Time (hours) Precip. (inches) Perv.Excess (inches) Imp.Excess (inches) Runoff (cfs) 0.00 0.00 0.00 0.00 0.00 1.00 0.54 0.00 0.35 1.37 2.00 0.94 0.05 0.73 0.34 3.00 1.14 0.11 0.93 0.06 4.00 1.14 0.11 0.93 0.00 5.00 1.14 0.11 0.93 0.00 6.00 1.14 0.11 0.93 0.00 7.00 1.14 0.11 0.93 0.00 8.00 1.14 0.11 0.93 0.00 9.00 1.14 0.11 0.93 0.00 10.00 1.14 0.11 0.93 0.00 11.00 1.14 0.11 0.93 0.00 12.00 1.14 0.11 0.93 0.00 13.00 1.14 0.11 0.93 0.00 14.00 1.14 0.11 0.93 0.00 15.00 1.14 0.11 0.93 0.00 16.00 1.14 0.11 0.93 0.00 17.00 1.14 0.11 0.93 0.00 18.00 1.14 0.11 0.93 0.00 19.00 1.14 0.11 0.93 0.00 20.00 1.14 0.11 0.93 0.00 21.00 1.14 0.11 0.93 0.00 22.00 1.14 0.11 0.93 0.00 23.00 1.14 0.11 0.93 0.00 24.00 1.14 0.11 0.93 0.00 25.00 1.14 0.11 0.93 0.00 26.00 1.14 0.11 0.93 0.00 27.00 1.14 0.11 0.93 0.00 28.00 1.14 0.11 0.93 0.00 29.00 1.14 0.11 0.93 0.00 30.00 1.14 0.11 0.93 0.00 31.00 1.14 0.11 0.93 0.00 32.00 1.14 0.11 0.93 0.00 33.00 1.14 0.11 0.93 0.00 34.00 1.14 0.11 0.93 0.00 35.00 1.14 0.11 0.93 0.00 36.00 1.14 0.11 0.93 0.00 37.00 1.14 0.11 0.93 0.00 38.00 1.14 0.11 0.93 0.00 39.00 1.14 0.11 0.93 0.00 40.00 1.14 0.11 0.93 0.00 41.00 1.14 0.11 0.93 0.00 42.00 1.14 0.11 0.93 0.00 43.00 1.14 0.11 0.93 0.00 44.00 1.14 0.11 0.93 0.00 45.00 1.14 0.11 0.93 0.00 46.00 1.14 0.11 0.93 0.00 47.00 1.14 0.11 0.93 0.00 48.00 1.14 0.11 0.93 0.00 49.00 1.14 0.11 0.93 0.00 50.00 1.14 0.11 0.93 0.00 ---PAGE BREAK--- Type IA 24-hr 2.86 hrs 25 yr Rainfall=1.14" 119 N Pacific Hwy Woodburn Printed 2/27/2023 Prepared by {enter your company name here} Page 20 HydroCAD® 10.00-26 s/n 01638 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 2S: Undeveloped [49] Hint: Tc<2dt may require smaller dt Runoff = 0.22 cfs @ 1.09 hrs, Volume= 0.029 af, Depth= 0.27" Runoff by SBUH method, Split Pervious/Imperv., Time Span= 0.00-50.00 hrs, dt= 0.05 hrs Type IA 24-hr 2.86 hrs 25 yr Rainfall=1.14" Area (sf) CN Description 54,860 86 <50% Grass cover, Poor, HSG C 54,860 86 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 2S: Undeveloped Runoff Hydrograph Time (hours) 50 48 46 44 42 40 38 36 34 32 30 28 26 24 22 20 18 16 14 12 10 8 6 4 2 0 Flow (cfs) 0.24 0.23 0.22 0.21 0.2 0.19 0.18 0.17 0.16 0.15 0.14 0.13 0.12 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 Type IA 24-hr 2.86 hrs 25 yr Rainfall=1.14" Runoff Area=54,860 sf Runoff Volume=0.029 af Runoff Depth=0.27" Tc=5.0 min CN=86/0 0.22 cfs ---PAGE BREAK--- Type IA 24-hr 2.86 hrs 25 yr Rainfall=1.14" 119 N Pacific Hwy Woodburn Printed 2/27/2023 Prepared by {enter your company name here} Page 21 HydroCAD® 10.00-26 s/n 01638 © 2020 HydroCAD Software Solutions LLC Hydrograph for Subcatchment 2S: Undeveloped Time (hours) Precip. (inches) Perv.Excess (inches) Imp.Excess (inches) Runoff (cfs) 0.00 0.00 0.00 0.00 0.00 1.00 0.54 0.02 0.00 0.18 2.00 0.94 0.17 0.00 0.17 3.00 1.14 0.27 0.00 0.03 4.00 1.14 0.27 0.00 0.00 5.00 1.14 0.27 0.00 0.00 6.00 1.14 0.27 0.00 0.00 7.00 1.14 0.27 0.00 0.00 8.00 1.14 0.27 0.00 0.00 9.00 1.14 0.27 0.00 0.00 10.00 1.14 0.27 0.00 0.00 11.00 1.14 0.27 0.00 0.00 12.00 1.14 0.27 0.00 0.00 13.00 1.14 0.27 0.00 0.00 14.00 1.14 0.27 0.00 0.00 15.00 1.14 0.27 0.00 0.00 16.00 1.14 0.27 0.00 0.00 17.00 1.14 0.27 0.00 0.00 18.00 1.14 0.27 0.00 0.00 19.00 1.14 0.27 0.00 0.00 20.00 1.14 0.27 0.00 0.00 21.00 1.14 0.27 0.00 0.00 22.00 1.14 0.27 0.00 0.00 23.00 1.14 0.27 0.00 0.00 24.00 1.14 0.27 0.00 0.00 25.00 1.14 0.27 0.00 0.00 26.00 1.14 0.27 0.00 0.00 27.00 1.14 0.27 0.00 0.00 28.00 1.14 0.27 0.00 0.00 29.00 1.14 0.27 0.00 0.00 30.00 1.14 0.27 0.00 0.00 31.00 1.14 0.27 0.00 0.00 32.00 1.14 0.27 0.00 0.00 33.00 1.14 0.27 0.00 0.00 34.00 1.14 0.27 0.00 0.00 35.00 1.14 0.27 0.00 0.00 36.00 1.14 0.27 0.00 0.00 37.00 1.14 0.27 0.00 0.00 38.00 1.14 0.27 0.00 0.00 39.00 1.14 0.27 0.00 0.00 40.00 1.14 0.27 0.00 0.00 41.00 1.14 0.27 0.00 0.00 42.00 1.14 0.27 0.00 0.00 43.00 1.14 0.27 0.00 0.00 44.00 1.14 0.27 0.00 0.00 45.00 1.14 0.27 0.00 0.00 46.00 1.14 0.27 0.00 0.00 47.00 1.14 0.27 0.00 0.00 48.00 1.14 0.27 0.00 0.00 49.00 1.14 0.27 0.00 0.00 50.00 1.14 0.27 0.00 0.00 ---PAGE BREAK--- Type IA 24-hr 2.86 hrs 25 yr Rainfall=1.14" 119 N Pacific Hwy Woodburn Printed 2/27/2023 Prepared by {enter your company name here} Page 22 HydroCAD® 10.00-26 s/n 01638 © 2020 HydroCAD Software Solutions LLC Summary for Pond 1P: SC-310 Chambers Inflow Area = 1.259 ac, 89.80% Impervious, Inflow Depth = 0.84" for 25 yr event Inflow = 1.38 cfs @ 1.01 hrs, Volume= 0.089 af Outflow = 0.10 cfs @ 2.96 hrs, Volume= 0.089 af, Atten= 93%, Lag= 117.3 min Primary = 0.10 cfs @ 2.96 hrs, Volume= 0.089 af Routing by Stor-Ind method, Time Span= 0.00-50.00 hrs, dt= 0.05 hrs / 2 Peak Elev= 2.05' @ 2.96 hrs Surf.Area= 2,775 sf Storage= 3,229 cf Plug-Flow detention time= 429.6 min calculated for 0.089 af (100% of inflow) Center-of-Mass det. time= 429.1 min ( 519.6 - 90.5 ) Volume Invert Avail.Storage Storage Description #1 0.00' 1,949 cf Custom Stage Data (Prismatic) Listed below (Recalc) 6,466 cf Overall - 1,592 cf Embedded = 4,874 cf x 40.0% Voids #2 0.00' 1,592 cf ADS_StormTech SC-310 +Cap x 108 Inside #1 Effective Size= 28.9"W x 16.0"H 2.07 sf x 7.12'L = 14.7 cf Overall Size= 34.0"W x 16.0"H x 7.56'L with 0.44' Overlap 108 Chambers in 10 Rows 3,542 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 0.00 2,775 0 0 2.33 2,775 6,466 6,466 Device Routing Invert Outlet Devices #1 Primary 0.00' 1.6" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads #2 Primary 2.12' 18.0" Vert. Orifice/Grate C= 0.600 Primary OutFlow Max=0.10 cfs @ 2.96 hrs HW=2.05' (Free Discharge) 1=Orifice/Grate (Orifice Controls 0.10 cfs @ 6.89 fps) 2=Orifice/Grate ( Controls 0.00 cfs) ---PAGE BREAK--- Type IA 24-hr 2.86 hrs 25 yr Rainfall=1.14" 119 N Pacific Hwy Woodburn Printed 2/27/2023 Prepared by {enter your company name here} Page 23 HydroCAD® 10.00-26 s/n 01638 © 2020 HydroCAD Software Solutions LLC Pond 1P: SC-310 Chambers Inflow Primary Hydrograph Time (hours) 50 48 46 44 42 40 38 36 34 32 30 28 26 24 22 20 18 16 14 12 10 8 6 4 2 0 Flow (cfs) 1 0 Inflow Area=1.259 ac Peak Elev=2.05' Storage=3,229 cf 1.38 cfs 0.10 cfs Pond 1P: SC-310 Chambers Primary Stage-Discharge Discharge (cfs) 7 6 5 4 3 2 1 0 Elevation (feet) 3 2 1 0 Orifice/Grate Orifice/Grate ---PAGE BREAK--- Type IA 24-hr 2.86 hrs 25 yr Rainfall=1.14" 119 N Pacific Hwy Woodburn Printed 2/27/2023 Prepared by {enter your company name here} Page 24 HydroCAD® 10.00-26 s/n 01638 © 2020 HydroCAD Software Solutions LLC Pond 1P: SC-310 Chambers Storage Stage-Area-Storage Storage (cubic-feet) 3,500 3,000 2,500 2,000 1,500 1,000 500 0 Elevation (feet) 3 2 1 0 Custom Stage Data + ADS_StormTech SC-310 +Cap ---PAGE BREAK--- Type IA 24-hr 2.86 hrs 25 yr Rainfall=1.14" 119 N Pacific Hwy Woodburn Printed 2/27/2023 Prepared by {enter your company name here} Page 25 HydroCAD® 10.00-26 s/n 01638 © 2020 HydroCAD Software Solutions LLC Hydrograph for Pond 1P: SC-310 Chambers Time (hours) Inflow (cfs) Storage (cubic-feet) Elevation (feet) Primary (cfs) 0.00 0.00 0 0.00 0.00 1.00 1.37 875 0.40 0.04 2.00 0.34 2,616 1.50 0.08 3.00 0.06 3,226 2.05 0.10 4.00 0.00 2,909 1.76 0.09 5.00 0.00 2,601 1.48 0.08 6.00 0.00 2,319 1.23 0.07 7.00 0.00 2,062 1.04 0.07 8.00 0.00 1,824 0.90 0.06 9.00 0.00 1,603 0.77 0.06 10.00 0.00 1,399 0.66 0.05 11.00 0.00 1,209 0.57 0.05 12.00 0.00 1,034 0.48 0.05 13.00 0.00 873 0.40 0.04 14.00 0.00 727 0.33 0.04 15.00 0.00 594 0.27 0.03 16.00 0.00 475 0.22 0.03 17.00 0.00 369 0.17 0.03 18.00 0.00 277 0.13 0.02 19.00 0.00 198 0.09 0.02 20.00 0.00 133 0.06 0.02 21.00 0.00 88 0.04 0.01 22.00 0.00 58 0.03 0.01 23.00 0.00 38 0.02 0.00 24.00 0.00 25 0.01 0.00 25.00 0.00 16 0.01 0.00 26.00 0.00 11 0.00 0.00 27.00 0.00 7 0.00 0.00 28.00 0.00 5 0.00 0.00 29.00 0.00 3 0.00 0.00 30.00 0.00 2 0.00 0.00 31.00 0.00 1 0.00 0.00 32.00 0.00 1 0.00 0.00 33.00 0.00 1 0.00 0.00 34.00 0.00 0 0.00 0.00 35.00 0.00 0 0.00 0.00 36.00 0.00 0 0.00 0.00 37.00 0.00 0 0.00 0.00 38.00 0.00 0 0.00 0.00 39.00 0.00 0 0.00 0.00 40.00 0.00 0 0.00 0.00 41.00 0.00 0 0.00 0.00 42.00 0.00 0 0.00 0.00 43.00 0.00 0 0.00 0.00 44.00 0.00 0 0.00 0.00 45.00 0.00 0 0.00 0.00 46.00 0.00 0 0.00 0.00 47.00 0.00 0 0.00 0.00 48.00 0.00 0 0.00 0.00 49.00 0.00 0 0.00 0.00 50.00 0.00 0 0.00 0.00 ---PAGE BREAK--- Type IA 24-hr 2.86 hrs 25 yr Rainfall=1.14" 119 N Pacific Hwy Woodburn Printed 2/27/2023 Prepared by {enter your company name here} Page 26 HydroCAD® 10.00-26 s/n 01638 © 2020 HydroCAD Software Solutions LLC Stage-Discharge for Pond 1P: SC-310 Chambers Elevation (feet) Primary (cfs) 0.00 0.00 0.02 0.00 0.04 0.01 0.06 0.02 0.08 0.02 0.10 0.02 0.12 0.02 0.14 0.03 0.16 0.03 0.18 0.03 0.20 0.03 0.22 0.03 0.24 0.03 0.26 0.03 0.28 0.04 0.30 0.04 0.32 0.04 0.34 0.04 0.36 0.04 0.38 0.04 0.40 0.04 0.42 0.04 0.44 0.04 0.46 0.05 0.48 0.05 0.50 0.05 0.52 0.05 0.54 0.05 0.56 0.05 0.58 0.05 0.60 0.05 0.62 0.05 0.64 0.05 0.66 0.05 0.68 0.06 0.70 0.06 0.72 0.06 0.74 0.06 0.76 0.06 0.78 0.06 0.80 0.06 0.82 0.06 0.84 0.06 0.86 0.06 0.88 0.06 0.90 0.06 0.92 0.06 0.94 0.07 0.96 0.07 0.98 0.07 1.00 0.07 1.02 0.07 Elevation (feet) Primary (cfs) 1.04 0.07 1.06 0.07 1.08 0.07 1.10 0.07 1.12 0.07 1.14 0.07 1.16 0.07 1.18 0.07 1.20 0.07 1.22 0.07 1.24 0.07 1.26 0.08 1.28 0.08 1.30 0.08 1.32 0.08 1.34 0.08 1.36 0.08 1.38 0.08 1.40 0.08 1.42 0.08 1.44 0.08 1.46 0.08 1.48 0.08 1.50 0.08 1.52 0.08 1.54 0.08 1.56 0.08 1.58 0.08 1.60 0.09 1.62 0.09 1.64 0.09 1.66 0.09 1.68 0.09 1.70 0.09 1.72 0.09 1.74 0.09 1.76 0.09 1.78 0.09 1.80 0.09 1.82 0.09 1.84 0.09 1.86 0.09 1.88 0.09 1.90 0.09 1.92 0.09 1.94 0.09 1.96 0.09 1.98 0.09 2.00 0.10 2.02 0.10 2.04 0.10 2.06 0.10 Elevation (feet) Primary (cfs) 2.08 0.10 2.10 0.10 2.12 0.10 2.14 0.10 2.16 0.11 2.18 0.12 2.20 0.13 2.22 0.15 2.24 0.18 2.26 0.21 2.28 0.24 2.30 0.28 2.32 0.32 2.34 0.36 2.36 0.41 2.38 0.46 2.40 0.51 2.42 0.57 2.44 0.64 2.46 0.70 2.48 0.77 2.50 0.85 2.52 0.92 2.54 1.00 2.56 1.08 2.58 1.17 2.60 1.26 2.62 1.35 2.64 1.44 2.66 1.54 2.68 1.64 2.70 1.75 2.72 1.85 2.74 1.96 2.76 2.07 2.78 2.18 2.80 2.30 2.82 2.42 2.84 2.54 2.86 2.66 2.88 2.78 2.90 2.91 2.92 3.03 2.94 3.16 2.96 3.29 2.98 3.42 3.00 3.56 3.02 3.69 3.04 3.83 3.06 3.96 3.08 4.10 3.10 4.24 Elevation (feet) Primary (cfs) 3.12 4.38 3.14 4.52 3.16 4.66 3.18 4.80 3.20 4.94 3.22 5.08 3.24 5.22 3.26 5.36 3.28 5.50 3.30 5.64 3.32 5.77 3.34 5.91 3.36 6.05 3.38 6.18 3.40 6.31 3.42 6.44 3.44 6.57 3.46 6.69 3.48 6.81 3.50 6.93 3.52 7.04 3.54 7.15 3.56 7.25 3.58 7.34 3.60 7.43 3.62 7.50 ---PAGE BREAK--- Type IA 24-hr 2.86 hrs 25 yr Rainfall=1.14" 119 N Pacific Hwy Woodburn Printed 2/27/2023 Prepared by {enter your company name here} Page 27 HydroCAD® 10.00-26 s/n 01638 © 2020 HydroCAD Software Solutions LLC Stage-Area-Storage for Pond 1P: SC-310 Chambers Elevation (feet) Storage (cubic-feet) 0.00 0 0.05 111 0.10 222 0.15 332 0.20 441 0.25 549 0.30 656 0.35 762 0.40 867 0.45 971 0.50 1,073 0.55 1,174 0.60 1,274 0.65 1,372 0.70 1,468 0.75 1,562 0.80 1,654 0.85 1,744 0.90 1,832 0.95 1,916 1.00 1,998 1.05 2,075 1.10 2,147 1.15 2,215 1.20 2,278 1.25 2,339 1.30 2,398 1.35 2,454 1.40 2,509 1.45 2,565 1.50 2,620 1.55 2,676 1.60 2,731 1.65 2,787 1.70 2,842 1.75 2,898 1.80 2,953 1.85 3,009 1.90 3,064 1.95 3,120 2.00 3,175 2.05 3,231 2.10 3,286 2.15 3,342 2.20 3,397 2.25 3,453 2.30 3,508 2.35 3,542 2.40 3,542 2.45 3,542 2.50 3,542 2.55 3,542 Elevation (feet) Storage (cubic-feet) 2.60 3,542 2.65 3,542 2.70 3,542 2.75 3,542 2.80 3,542 2.85 3,542 2.90 3,542 2.95 3,542 3.00 3,542 3.05 3,542 3.10 3,542 3.15 3,542 3.20 3,542 3.25 3,542 3.30 3,542 3.35 3,542 3.40 3,542 3.45 3,542 3.50 3,542 3.55 3,542 3.60 3,542 ---PAGE BREAK--- Hydrology 7 - A - 1 APPENDIX A - RAINFALL INTENSITY - DURATION - RECURRENCE INTERVAL CURVES 1.0 Derivation of Curves The Rainfall Intensity - Duration - Recurrence Interval (I-D-R) curves were computed in accordance with the method described in the 1973 NOAA Atlas 2 titled "Precipitation-Frequency Atlas of the Western United States, Volume X-Oregon." A regional rainfall analysis was made by comparing rainfall data for 136 cities and areas, and thirteen zones were established that have similar rainfall intensities. A set of I-D-R curves were calculated for each zone and the curves represent average values for that zone. 2.0 Use of Curves The first step is to determine the zone in which the project is located. This can be accomplished by either using the enclosed map that shows the various zones or the alphabetical listing of cities and their corresponding zones. When the proper zone is located, the I-D-R curves for that zone will provide the needed rainfall intensities. The designer must use engineering judgement in selecting the proper zone if the proposed project lies within two zones or is on or near a dividing line. The zone with larger intensity should be used if no personal knowledge of the area is available, as this gives the most conservative design. Note: Rainfall Zone Map and Rainfall Zone Map with Highway Milepoints are in pdf formats. April 2014 ODOT Hydraulics Manual ---PAGE BREAK--- Hydrology 7 - A - 5 TABLE 1: INDEX TO RAINFALL INTENSITY-DURATION-RECURRENCE INTERVAL CURVES City Zone The Dalles 11 Tidewater 4 Tillamook 2 Tiller 6 Toledo 2 Union 13 Union Creek 3 Umatilla 13 Vale 13 Veneta 5 Vernonia 8 Vida 5 Wagontire 13 Waldport 2 Wallowa 10 Willamina 8 Wilsonville 7 Woodburn 7 City Zone Yachats 2 Yamhill 8 April 2014 ODOT Hydraulics Manual ---PAGE BREAK--- ---PAGE BREAK--- 25yr JMS Date: NWS Upstream Structure Structure Area Area Runoff Coeff. Equiv. Area Total Drainage Area Time of Concent. Or Flow Time Total Time of Concent. Average Rainfall Intensity Design Discharge IE (in) IE (out) Pipe Length Min. Invert Slope Pipe Size Capacity Flowing Full Velocity Flowing Full Flow Time (cA) (cA) sqft acres acres acres min min in/hr cfs ft ft ft % in cfs fps min 2/27/2023 Designed By: Checked By: Project Name: 119 Pacific Highway Project A21194.10 Design Frequency: RD-01 A 684.5 0.016 0.90 0.014 0.014 5.0 5.0 2.45 0.035 187.10 186.84 54.00 0.5% 6 0.39 1.99 0.5 RD-02 A 684.5 0.016 0.90 0.014 0.014 5.0 5.0 2.45 0.035 187.10 186.84 3.00 8.7% 6 1.66 8.43 0.0 A B 0.000 0.90 0.000 0.028 5.0 5.0 2.45 0.069 186.84 186.68 33.00 0.5% 6 0.39 1.99 0.3 RD-03 B 684.5 0.016 0.90 0.014 0.014 5.0 5.0 2.45 0.035 187.10 186.68 4.00 10.5% 6 1.82 9.28 0.0 B CO-09 0.000 0.90 0.000 0.042 5.0 5.0 2.45 0.104 186.68 186.58 20.00 0.5% 6 0.40 2.02 0.2 RD-04 CO-09 684.5 0.016 0.90 0.014 0.014 5.0 5.0 2.45 0.035 187.10 186.58 3.00 17.3% 6 2.34 11.92 0.0 CO-09 C 0.000 0.90 0.000 0.057 5.0 5.0 2.45 0.139 186.58 186.39 37.00 0.5% 6 0.40 2.05 0.3 RD-05 C 684.5 0.016 0.90 0.014 0.014 5.0 5.0 2.45 0.035 187.10 186.39 3.00 23.7% 6 2.74 13.93 0.0 C D 0.000 0.90 0.000 0.071 5.0 5.0 2.45 0.173 186.39 186.33 13.00 0.5% 6 0.38 1.95 0.1 RD-06 D 684.5 0.016 0.90 0.014 0.014 5.0 5.0 2.45 0.035 187.10 186.33 3.00 25.7% 6 2.85 14.51 0.0 D CO-08 0.000 0.90 0.000 0.085 5.0 5.0 2.45 0.208 186.33 186.15 37.00 0.5% 6 0.39 2.00 0.3 RD-07 CO-08 684.5 0.016 0.90 0.014 0.014 5.0 5.0 2.45 0.035 187.10 186.15 3.00 31.7% 6 3.16 16.11 0.0 CO-08 E 0.000 0.90 0.000 0.099 5.0 5.0 2.45 0.243 186.15 186.03 25.00 0.5% 6 0.39 1.98 0.2 RD-08 E 684.5 0.016 0.90 0.014 0.014 5.0 5.0 2.45 0.035 187.10 186.03 4.00 26.7% 6 2.91 14.81 0.0 E F 0.000 0.90 0.000 0.113 5.0 5.0 2.45 0.277 186.03 185.93 21.00 0.5% 6 0.39 1.98 0.2 RD-09 F 684.5 0.016 0.90 0.014 0.014 5.0 5.0 2.45 0.035 187.10 185.93 3.00 39.0% 6 3.51 17.88 0.0 F CO-07 0.000 0.90 0.000 0.127 5.0 5.0 2.45 0.312 185.93 185.76 34.00 0.5% 6 0.40 2.02 0.3 RD-10 CO-07 684.5 0.016 0.90 0.014 0.014 5.0 5.0 2.45 0.035 187.10 185.76 3.00 44.7% 6 3.76 19.14 0.0 CO-07 G 0.000 0.90 0.000 0.141 5.0 5.0 2.45 0.346 185.76 185.60 34.00 0.5% 6 0.39 1.96 0.3 RD-11 G 684.5 0.016 0.90 0.014 0.014 5.0 5.0 2.45 0.035 187.10 185.60 3.00 50.0% 6 3.98 20.25 0.0 G H 0.000 0.90 0.000 0.156 5.0 5.0 2.45 0.381 185.60 185.43 34.00 0.5% 6 0.40 2.02 0.3 RD-12 H 684.5 0.016 0.90 0.014 0.014 5.0 5.0 2.45 0.035 187.10 185.43 3.00 55.7% 6 4.19 21.36 0.0 H I 0.000 0.90 0.000 0.170 5.0 5.0 2.45 0.416 185.43 185.20 47.00 0.5% 8 0.85 2.43 0.3 0.000 0.90 0.000 0.000 5.0 5.0 3.40 0.000 RD-16 J 684.5 0.016 0.90 0.014 0.170 5.0 5.0 2.45 0.416 187.10 186.63 25.00 1.9% 6 0.77 3.93 0.1 Page 1 ---PAGE BREAK--- 25yr JMS Date: NWS Upstream Structure Structure Area Area Runoff Coeff. Equiv. Area Total Drainage Area Time of Concent. Or Flow Time Total Time of Concent. Average Rainfall Intensity Design Discharge IE (in) IE (out) Pipe Length Min. Invert Slope Pipe Size Capacity Flowing Full Velocity Flowing Full Flow Time (cA) (cA) sqft acres acres acres min min in/hr cfs ft ft ft % in cfs fps min 2/27/2023 Designed By: Checked By: Project Name: 119 Pacific Highway Project A21194.10 Design Frequency: RD-15 J 684.5 0.016 0.90 0.014 0.184 5.0 5.0 2.45 0.450 187.10 186.63 3.00 15.7% 6 2.23 11.33 0.0 J K 0.000 0.90 0.000 0.354 5.0 5.0 2.45 0.866 186.63 186.12 27.00 1.9% 8 1.66 4.77 0.1 RD-14 K 684.5 0.016 0.90 0.014 0.014 5.0 5.0 2.45 0.035 187.10 186.12 3.00 32.7% 6 3.21 16.37 0.0 K L 0.000 0.90 0.000 0.368 5.0 5.0 2.45 0.901 186.12 185.31 43.00 1.9% 8 1.66 4.76 0.2 RD-13 L 684.5 0.016 0.90 0.014 0.552 5.0 5.0 2.45 1.351 187.10 185.31 3.00 59.7% 6 4.34 22.12 0.0 L I 0.000 0.90 0.000 0.919 5.0 5.0 2.45 2.252 185.31 185.20 6.00 1.8% 10 2.97 5.45 0.0 0.000 0.90 0.000 0.000 5.0 5.0 2.45 0.000 I M 0.000 0.90 0.000 1.089 5.0 5.0 2.45 2.668 185.20 184.81 80.00 0.5% 18 7.35 4.16 0.3 CB-02 M 1688 0.039 0.90 0.035 0.035 5.0 5.0 2.45 0.085 185.22 184.81 7.00 5.9% 6 1.36 6.93 0.0 M N 0.000 0.90 0.000 1.124 5.0 5.0 2.45 2.753 184.81 184.71 6.00 1.7% 18 13.59 7.69 0.0 CB-01 N 5215 0.120 0.90 0.108 0.108 5.0 5.0 2.45 0.264 184.84 184.71 27.00 0.5% 6 0.39 1.99 0.2 N O 0.000 0.90 0.000 1.232 5.0 5.0 2.45 3.017 184.71 184.49 44.00 0.5% 18 7.45 4.21 0.2 0.000 0.90 0.000 0.000 5.0 5.0 2.45 0.000 CB-07 P 2449 0.056 0.90 0.051 0.051 5.0 5.0 2.45 0.124 185.09 184.61 96.00 0.5% 6 0.40 2.02 0.8 CB-03 P 1577 0.036 0.90 0.033 0.033 5.0 5.0 2.45 0.080 184.80 184.61 21.00 0.9% 6 0.53 2.72 0.1 P O 0.000 0.90 0.000 0.083 5.0 5.0 2.45 0.204 184.61 184.49 25.00 0.5% 6 0.39 1.98 0.2 0.000 0.90 0.000 0.000 5.0 5.0 2.45 0.000 O X 0.000 0.90 0.000 1.315 5.0 5.0 2.45 3.221 184.49 184.46 6.00 0.5% 18 7.45 4.21 0.0 0.000 0.90 0.000 0.000 5.0 5.0 2.45 0.000 RD-17 Q 684.5 0.016 0.90 0.014 0.014 5.0 5.0 2.45 0.035 187.10 186.88 25.00 0.9% 6 0.53 2.69 0.2 RD-18 Q 684.5 0.016 0.90 0.014 0.014 5.0 5.0 2.45 0.035 187.10 186.88 3.00 7.3% 6 1.52 7.75 0.0 Q R 0.000 0.90 0.000 0.028 5.0 5.0 2.45 0.069 186.88 186.63 27.00 0.9% 6 0.54 2.76 0.2 RD-19 R 684.5 0.016 0.90 0.014 0.014 5.0 5.0 2.45 0.035 187.10 186.63 3.00 15.7% 6 2.23 11.33 0.0 R S 0.000 0.90 0.000 0.042 5.0 5.0 2.45 0.104 186.63 186.43 24.00 0.8% 6 0.51 2.61 0.2 0.000 0.90 0.000 0.000 5.0 5.0 2.45 0.000 Page 2 ---PAGE BREAK--- 25yr JMS Date: NWS Upstream Structure Structure Area Area Runoff Coeff. Equiv. Area Total Drainage Area Time of Concent. Or Flow Time Total Time of Concent. Average Rainfall Intensity Design Discharge IE (in) IE (out) Pipe Length Min. Invert Slope Pipe Size Capacity Flowing Full Velocity Flowing Full Flow Time (cA) (cA) sqft acres acres acres min min in/hr cfs ft ft ft % in cfs fps min 2/27/2023 Designed By: Checked By: Project Name: 119 Pacific Highway Project A21194.10 Design Frequency: RD-21 T 684.5 0.016 0.90 0.014 0.014 5.0 5.0 2.45 0.035 187.10 186.64 44.00 1.0% 6 0.57 2.93 0.3 RD-20 T 684.5 0.016 0.90 0.014 0.014 5.0 5.0 2.45 0.035 187.10 186.64 3.00 15.3% 6 2.20 11.21 0.0 T S 0.000 0.90 0.000 0.028 5.0 5.0 2.45 0.069 186.64 186.43 20.00 1.0% 6 0.58 2.93 0.1 0.000 0.90 0.000 0.000 5.0 5.0 2.45 0.000 S U 0.000 0.90 0.000 0.071 5.0 5.0 2.45 0.173 186.43 185.18 80.00 1.6% 6 0.70 3.58 0.4 CB-05 U 8226 0.189 0.90 0.170 0.170 5.0 5.0 2.45 0.416 185.28 185.18 21.00 0.5% 8 0.84 2.39 0.1 U V 0.000 0.90 0.000 0.241 5.0 5.0 2.45 0.590 185.18 185.03 30.00 0.5% 8 0.86 2.45 0.2 CB-04 V 5978 0.137 0.90 0.124 0.124 5.0 5.0 2.45 0.303 185.06 185.03 5.00 0.6% 6 0.44 2.22 0.0 V W 0.000 0.90 0.000 0.364 5.0 5.0 2.45 0.892 185.03 184.66 74.00 0.5% 10 1.55 2.85 0.4 CB-06 W 5978 0.137 0.90 0.124 0.124 5.0 5.0 2.45 0.303 184.69 184.66 6.00 0.5% 6 0.40 2.02 0.0 W X 0.000 0.90 0.000 0.488 5.0 5.0 2.45 1.195 184.66 184.47 39.00 0.5% 10 1.53 2.81 0.2 0.000 0.90 0.000 0.000 5.0 5.0 2.45 0.000 X MH-01 0.000 0.90 0.000 1.802 5.0 5.0 2.45 4.416 184.47 184.43 7.41 0.5% 18 7.74 4.38 0.0 MH-01 DET 0.000 0.90 0.000 1.802 5.0 5.0 2.45 4.416 184.43 184.40 5.50 0.5% 18 7.78 4.40 0.0 DET FCMH-01 0.000 0.90 0.000 1.802 5.0 5.0 2.45 4.416 184.40 184.40 10.00 0.0% 18 1.05 0.60 0.3 FCMH-01 OUT 0.000 0.90 0.000 1.802 5.0 5.0 2.45 4.416 184.40 183.89 102.00 0.5% 18 7.45 4.21 0.4 Page 3 ---PAGE BREAK--- 119 N Pacific Hwy E Appendix E Operations and Maintenance ---PAGE BREAK--- Isolator® Row O&M Manual ---PAGE BREAK--- 2 Looking down the Isolator Row from the manhole opening, woven geotextile Fabric is shown between the chamber and stone base. StormTech Isolator Row with Overflow Spillway (not to scale) The Isolator® Row Introduction An important component of any Stormwater Pollution Prevention Plan is inspection and maintenance. The StormTech Isolator Row is a technique to inexpensively enhance Total Suspended Solids (TSS) and Total Phosphorus (TP) removal with easy access for inspection and maintenance. The Isolator Row The Isolator Row is a row of StormTech chambers, either SC-160, SC- 310, SC-310-3, SC-740, DC-780, MC-3500 or MC-7200 models, that is surrounded with filter fabric and connected to a closely located manhole for easy access. The fabric-wrapped chambers provide for sediment settling and filtration as stormwater rises in the Isolator Row and passes through the filter fabric. The open bottom chambers and perforated sidewalls (SC-310, SC- 310-3 and SC-740 models) allow stormwater to flow both vertically and horizontally out of the chambers. Sediments are captured in the Isolator Row protecting the adjacent stone and chambers storage areas from sediment accumulation. ADS geotextile fabric is placed between the stone and the Isolator Row chambers. The woven geotextile provides a media for stormwater filtration, a durable surface for maintenance, prevents scour of the underlying stone and remains intact during high pressure jetting. A non-woven fabric is placed over the chambers to provide a filter media for flows passing through the chamber’s sidewall. The non-woven fabric is not required over the SC-160, DC-780, MC-3500 or MC-7200 models as these chambers do not have perforated side walls. The Isolator Row is designed to capture the “first flush” runoff and offers the versatility to be sized on a volume basis or a flow-rate basis. An upstream manhole provides access to the Isolator Row and includes a high/low concept such that stormwater flow rates or volumes that exceed the capacity of the Isolator Row bypass through a manifold to the other chambers. This is achieved with an elevated bypass manifold or a high-flow weir. This creates a differential between the Isolator Row row of chambers and the manifold to the rest of the system, thus allowing for settlement time in the Isolator Row. After Stormwater flows through the Isolator Row and into the rest of the chamber system it is either exfiltrated into the soils below or passed at a controlled rate through an outlet manifold and outlet control structure. The Isolator Row may be part of a treatment train system. The treatment train design and pretreatment device selection by the design engineer is often driven by regulatory requirements. Whether pretreatment is used or not, StormTech recommend using the Isolator Row to minimize maintenance requirements and maintenance costs. Note: See the StormTech Design Manual for detailed information on designing inlets for a StormTech system, including the Isolator Row. ECCENTRIC HEADER MANHOLE WITH OVERFLOW WEIR STORMTECH ISOLATOR ROW OPTIONAL PRE-TREATMENT OPTIONAL ACCESS STORMTECH CHAMBERS ---PAGE BREAK--- 3 Inspection The frequency of inspection and maintenance varies by location. A routine inspection schedule needs to be established for each individual location based upon site specific variables. The type of land use (i.e. industrial, commercial, residential), anticipated pollutant load, percent imperviousness, climate, etc. all play a critical role in determining the actual frequency of inspection and maintenance practices. At a minimum, StormTech recommends annual inspections. Initially, the Isolator Row should be inspected every 6 months for the first year of operation. For subsequent years, the inspection should be adjusted based upon previous observation of sediment deposition. The Isolator Row incorporates a combination of standard manhole(s) and strategically located inspection ports (as needed). The inspection ports allow for easy access to the system from the surface, eliminating the need to perform a confined space entry for inspection purposes. If upon visual inspection it is found that sediment has accumulated, a stadia rod should be inserted to determine the depth of sediment. When the average depth of sediment exceeds 3 inches throughout the length of the Isolator Row, clean-out should be performed. Maintenance The Isolator Row was designed to reduce the cost of periodic maintenance. By “isolating” sediments to just one row, costs are dramatically reduced by eliminating the need to clean out each row of the entire storage bed. If inspection indicates the potential need for maintenance, access is provided via a manhole(s) located on the end(s) of the row for cleanout. If entry into the manhole is required, please follow local and OSHA rules for a confined space entries. Maintenance is accomplished with the JetVac process. The JetVac process utilizes a high pressure water nozzle to propel itself down the Isolator Row while scouring and suspending sediments. As the nozzle is retrieved, the captured pollutants are flushed back into the manhole for vacuuming. Most sewer and pipe maintenance companies have vacuum/JetVac combination vehicles. Selection of an appropriate JetVac nozzle will improve maintenance efficiency. Fixed nozzles designed for culverts or large diameter pipe cleaning are preferable. Rear facing jets with an effective spread of at least 45” are best. JetVac reels can vary in length. For ease of maintenance, ADS recommends Isolator Row up to 200" (61 The JetVac process shall only be performed on StormTech Isolator Rows that have AASHTO class 1 woven geotextile (as specified by StormTech) over their angular base stone. Isolator Row Inspection/Maintenance StormTech Isolator Row (not to scale) Note: Non-woven fabric is only required over the inlet pipe connection into the end cap for SC-160LP, DC-780, MC- 3500 and MC-7200 chamber models and is not required over the entire Isolator Row. ---PAGE BREAK--- Isolator Row Step By Step Maintenance Procedures Step 1 Inspect Isolator Row for sediment. A) Inspection ports (if present) i. Remove lid from floor box frame ii. Remove cap from inspection riser iii. Using a flashlight and stadia rod,measure depth of sediment and record results on maintenance log. iv. If sediment is at or above 3 inch depth, proceed to Step 2. If not, proceed to Step 3. B) All Isolator Row i. Remove cover from manhole at upstream end of Isolator Row ii. Using a flashlight, inspect down Isolator Row through outlet pipe 1. Mirrors on poles or cameras may be used to avoid a confined space entry 2. Follow OSHA regulations for confined space entry if entering manhole iii. If sediment is at or above the lower row of sidewall holes (approximately 3 inches), proceed to Step 2. If not, proceed to Step 3. Step 2 Clean out Isolator Row using the JetVac process. A) A fixed floor cleaning nozzle with rear facing nozzle spread of 45 inches or more is preferable B) Apply multiple passes of JetVac until backflush water is clean C) Vacuum manhole sump as required Step 3 Replace all caps, lids and covers, record observations and actions. Step 4 Inspect & clean catch basins and manholes upstream of the StormTech system. ADS “Terms and Conditions of Sale” are available on the ADS website, www.ads-pipe.com The ADS logo and the Green Stripe are registered trademarks of Advanced Drainage Systems, Inc. Stormtech® and the Isolator® Row are registered trademarks of StormTech, Inc. © 2022 Advanced Drainage Systems, Inc. #11011 2/22 CS Sample Maintenance Log Date Stadia Rod Readings Sedi- ment Depth Observations/Actions Inspector Fixed point to chamber bottom Fixed point to top of sediment 3/15/11 6.3 ft none New installation. Fixed point is CI frame at grade DJM 9/24/11 6.2 0.1 ft Some grit felt SM 6/20/13 5.8 0.5 ft Mucky feel, debris visible in manhole and in Isolator Row, maintenance due NV 7/7/13 6.3 ft 0 System jetted and vacuumed DJM adspipe.com [PHONE REDACTED]