Document Redmond_doc_50cf038921

Mitigation/Monitoring Report Hopelink Redmond Integrated Service Center Redmond, Washington Report Prepared by: PBS Engineering & Environmental October 2016 PBS Project # 41342 Applicant: Poppi Handy Third Place Design Co-operative 177 Western Avenue West, Suite 266 Seattle, WA 98119 [PHONE REDACTED] EXHIBIT I ---PAGE BREAK--- Hopelink Redmond Integrated Service Center Mitigation Monitoring Report Redmond, Washington October 2016 PBS Project: 41342.001 i MITIGATION / MONITORING REPORT Hopelink Redmond Integrated Service Center Redmond, Washington Prepared for Hopelink Redmond, Washington Prepared by: Katharine Lee, M.S. Ecologist, Professional Wetland Scientist PBS Engineering and Environmental 2517 Eastlake Ave East, Suite 100 Seattle, WA 98102 (206) 233-9639 PBS Project No: 41342.001 October, 2016 This report is for the exclusive use of the client for planned development of the property and is not to be relied upon by other parties. It is not to be photographed, photocopied, or similarly reproduced in total or in part without the expressed written consent of the client and PBS. EXHIBIT I ---PAGE BREAK--- Hopelink Redmond Integrated Service Center Mitigation Monitoring Report Redmond, Washington October 2016 PBS Project: 41342.001 ii TABLE OF CONTENTS TABLES iii Figures iii Appendices iii I. Executive Summary of Critical AReas Report 1 A. General Overview 1 B. Existing Condition 1 C. Project Description 1 D. Location 2 E. Description of Critical Areas 2 1. Sammamish River 2 2. Fish and Wildlife Habitat Conservation Areas 2 F. Avoidance / Minimization Measures 3 G. Proposed Mitigation Summary 3 II. Assessment of impacts 3 A. Area of Impact 3 B. Soils 3 C. Existing Vegetation in Buffer 4 D. Wildlife Use of Project Vicinity 4 E. Buffer Characterization 6 F. Water Quality 7 III. Proposed Mitigation Sites 7 IV. Existing Baseline Conditions of Mitigation Site 7 V. Mitigation Approach 8 A. Mitigation Sequencing 8 B. Project Specific Goals 8 C. Mitigation Strategy 8 D. Specific Goals, Objectives and Performance Standards 8 VI. Mitigation Design 10 VII. Irrigation Plan 12 VIII. Monitoring Plan 12 1. Baseline Monitoring 12 2. Monitoring Years 1 through 5 13 IX. Maintenance and Contingency plan 13 X. Reference 15 EXHIBIT I ---PAGE BREAK--- Hopelink Redmond Integrated Service Center Mitigation Monitoring Report Redmond, Washington October 2016 PBS Project: 41342.001 iii TABLES Table 1 Priority Species with a Potential Presence in the Vicinity of the Property Table 2 Riparian Corridor Functional Assessment Table 3 City of Redmond Performance Standards Applied to Mitigation Table 4 Performance Standards and Success Criteria Table 5 Planting Plan for Restored Buffer Area Table 6 Planting Plan for Enhanced Buffer Area Table 7 Noxious Weeds to be Targeted at Mitigation Site FIGURES Figure 1 Site Vicinity Map Figure 2 Proposed Site Plan Figure 3 Impact and Mitigation Areas Figure 4 Vegetative Cover Types Figure 5 Mitigation Planting Plan APPENDICES Appendix A – Site Photographs Appendix B – Plan Sheets EXHIBIT I ---PAGE BREAK--- Hopelink Redmond Integrated Service Center Mitigation Monitoring Report Redmond, Washington October 2016 PBS Project: 41342.001 1 I. EXECUTIVE SUMMARY OF CRITICAL AREAS REPORT A. General Overview Hopelink intends to develop an integrated service center in the City of Redmond, Washington. The permanent service center will provide a consistent place to receive and give help and will include space for an innovative food program, adult education, energy and emergency financial assistance programs, case management and employment services. Hopelink is applying for a Shoreline Substantial Development permit under the City’s Essential Public Facilities permitting process. A Critical Areas Report for the project was prepared in May of 2016 and has been approved by the City. Demolition of existing structures located in the Sammamish River shoreline zone, river buffer and fish & wildlife habitat conservation area will trigger mitigation under the Redmond Zoning Code (RZC). This mitigation/monitoring report has been prepared to address City of Redmond mitigation / monitoring requirements for impacts to these areas. The plan incorporates the Mitigation Plan requirements in RZC Section 21.64 and Appendix 1 of the RZC. The city file # for the project is 2016-0271 EPF. B. Existing Condition The proposed project will be built on land owned by the City of Redmond and currently occupied by the Sammamish River Business Park. The current parcel is over 2 acres and includes a portion of NE 90th Street, a retaining wall, and a pedestrian trail to the north. There are currently two 17,000 square foot 1-story buildings on the site. The property fronts 154th Ave NE to the west and the trail along NE 90th St to the north. Along the east side, the property borders a King County owned parcel located along the Sammamish River, which supports a multipurpose trail. The eastern boundary of the property is approximately 110 feet from the Ordinary High Water line of the Sammamish River. The two existing buildings occupy approximately 46 percent of the site. Parking lots and sidewalks occupy an addition 43 percent for a total of 89 percent impervious surface. Currently all stormwater runs directly into the Sammamish River with no treatment. C. Project Description The project will demo all existing buildings and most of the hardscape. A new two story building with a footprint of approximately14,000 square feet will be built on the site. The building will be located on the west half of the parcel, with approximately 74 parking spaces located primarily on the east half of the property. A greenhouse and plaza is planned for the center of the site. Access will be off of 154th Ave NW via a shared drive with the adjacent property to the south as is currently the case. Figure 2 shows the proposed site plan. The proposed project will reduce impervious surface by 10 percent. However, there will be a slight increase in pollution generating surfaces from 36% to 40% of the parcel. Stormwater from the roof drains will be collected and discharged directly to the Sammamish River via the existing stormwater pipe. Stormwater from the parking lot will be collected and treated prior to discharge to the river. Treatment will consist of six bio-retention areas; five at the south end of the parking lot and one at the north end. EXHIBIT I ---PAGE BREAK--- Hopelink Redmond Integrated Service Center Mitigation Monitoring Report Redmond, Washington October 2016 PBS Project: 41342.001 2 D. Location The project is located at 15511 NE 90th St. in Redmond, WA at the intersection of 154th Ave NE with NE 90th Street (King County parcel # 022509224) (Figure It is just south of the NE 90th St. Bridge over the Sammamish River on the west side of the river. The project is occurring in the NE ¼ of Section 2, T25N, R05E. E. Description of Critical Areas Critical areas identified on the project site include Sammamish River buffers, floodprone areas, fish and wildlife habitat conservation areas, and critical aquifer recharge areas. These are discussed in detail in the project Critical Areas Report (PBS 2016). This mitigation / monitoring report only discusses impacts to the Sammamish River buffer and fish and wildlife habitat conservation area associated with that buffer. 1. Sammamish River The Sammamish River is a shoreline of the state and a Class 1 water. The Shoreline designation on the property is High Intensity/Multi-Use. The Shoreline designation for the King County owned parcel to the east along the Sammamish River is Urban Conservancy. The 200 foot shoreline zone extends approximately 87 to 90 feet into the subject property and covers nearly a quarter of the property. The Sammamish River flows into the north end of Lake Washington, which flows out through the ship canal to Puget Sound. At the project location the river is 60 to 75 feet wide and up to 5 or 6 feet deep. The reach is primarily a glide reach with a slope of approximately 0.02 percent. When the river level was lowered back in the 1960s, relatively steep banks resulted. The river bank at the project site is approximately 10 feet high with 20 to 35 percent slopes, resulting in no connection to the floodplain on the west side of the river except in extreme floods. King County and the City of Redmond undertook a restoration project in 2002 at the project location that introduced some slight meandering to the previously straightened channel, pushed back the levee on the east side to create some gravel bars and floodplain, and added boulders and large wood features to the channel to create channel complexity. The banks were planted with native trees and shrubs. Buffers for Class 1 streams are 150 feet from the Ordinary High Water (OHW) mark. The Shoreline Designation extends 200 feet from OHW or to the edge of adjacent wetlands. OHW was mapped in the field to accurately determine the extent of the buffers and Shoreline Jurisdiction at the project site. The first 110 to 113 feet of the buffer is on county owned property. Only the last 37 to 40 feet extends onto the subject property. The first 15 to 20 feet of this buffer is a raised berm that was planted to native species with some volunteer native and non-native species. The remainder of the buffer is currently occupied by a sidewalk and a portion of a building. 2. Fish and Wildlife Habitat Conservation Areas The City has identified the Sammamish River and the King County property to the east of the subject property as critical wildlife habitat. The Sammamish River is a Class 1 stream so the 150 foot buffer is automatically considered a core preservation area. The river is considered an important wildlife corridor through the City, connecting higher value habitat areas to the south and north. EXHIBIT I ---PAGE BREAK--- Hopelink Redmond Integrated Service Center Mitigation Monitoring Report Redmond, Washington October 2016 PBS Project: 41342.001 3 F. Avoidance / Minimization Measures No new development will occur within the 150 foot Sammamish River buffer and habitat conservation area. Existing pavement and building encroachment will be removed except of a small area of existing pavement covering 200 square feet along the southern edge of the buffer that is needed for emergency vehicle turning. Most of the existing native vegetation along the east edge of the property in the buffer will be maintained, with the exception of the removal of four aspen trees in poor health. Water quality treatment will be added to treat runoff from impervious surfaces before it reaches the river, which will provide water quality improvement over the existing condition. The project will result in a net gain of riparian corridor and fish and wildlife habitat functions. G. Proposed Mitigation Summary Under 21.64.010Ce of the Redmond City Code, demolishing any structure that results in a disturbance of a critical area is a regulated activity and mitigation is required. The portion of the Fish and Wildlife Habitat Conservation area that was occupied by the office building and sidewalk will be restored by planting with native species, increasing the effective width of the stream buffer at this location by approximately 20 feet. The overall goal of the restoration plantings will be to provide an incremental increase in available habitat for species using the buffer along the river. A secondary goal is to improve water quality in the Sammamish River by reducing impervious surface near the river and treating runoff from pollution generating surfaces, which currently flows untreated into the river. The buffer restoration area measures approximately 4,400 square feet or 0.10 acre. The remaining 3,400 square feet of the buffer on the property will be enhanced through weed control and some plantings. The restored buffer area will be irrigated for at least 3 years to ensure plant survival and will be weeded at least three times a year. Monitoring will occur yearly for 5 years. Any mortality of planted stock will be replaced in kind or with an equivalent species approved by the qualified consultant. Other contingency measures may include adjustments to the watering regime, additional weed control, addition of mulch, replacement signage and fencing or trail maintenance. II. ASSESSMENT OF IMPACTS A. Area of Impact The impact consists of 3,720 square feet of buildings, concrete sidewalk and pavement that are being removed from the outer 20 feet of the Sammamish River buffer and habitat conservation area. B. Soils Soils are mapped as Snohomish Silt Loam, thick surface variant. This is a floodplain soil formed in alluvium and underlain with organic material such as muck. Layers of diatomaceous earth may also be present. While this soil type is somewhat poorly drained with a water table present several feet below the surface, it is not rated as a hydric soil. It is very likely that fill material was placed on the site when the business park was constructed. Recent well data from a groundwater monitoring well in the northeast corner of the site shows groundwater fluctuating between 4 and 12 feet below the surface. The condition of the soils under the building and sidewalk is unknown. EXHIBIT I ---PAGE BREAK--- Hopelink Redmond Integrated Service Center Mitigation Monitoring Report Redmond, Washington October 2016 PBS Project: 41342.001 4 C. Existing Vegetation in Buffer The portion of the buffer on the property that is currently vegetated measures approximately 3,400 square feet (0.08 acre). It is a constructed berm that is several feet higher than the surrounding area. It supports a mostly planted native forest community. Trees rooted on the property include three 14-16” diameter Douglas firs (Pseudotsuga menziesii), a 12 inch diameter non-native red maple (Acer rubra), one large multi-stem cottonwood (Populus balsamifera var. tricocarpa) and six 4-12 inch diameter quaking aspens (Populus tremuloides). The large cottonwood is mostly on the adjoining property to the south. Two other Douglas-firs (8.5” and 15”), a 13” big leaf maple (Acer a 11 inch red maple and a 16” cottonwood are rooted off the property, but have significant canopy cover over the property. The aspens and red maple were definitely planted, while the cottonwoods likely predate current development of the site. The Douglas-fir and big-leaf maple were likely planted but may have volunteered post disturbance. Other planted species include osoberry (Oemleria cerasiformis), swordfern (Polystichum munitum), snowberry albus), tall Oregon grape (Berberis aquifolium), sweetgale (Myrica gale), and lady fern (Athyrium filix-femina). There are many small aspen saplings that have become established either from root suckers or seed. Other species present on the berm include bentgrasses (Agrostis sp), other grasses, Himalayan blackberry (Rubus armeniacus), creeping buttercup (Ranunculus repens), field bindweed (Convolvulus arvensis) and western dock (Rumex occidentalis). The invasive species (blackberry and bindweed) are currently a minor component. It appears some of the plantings may have been associated with the King County river restoration plantings undertaken in 2002. The existing native vegetation on the berm will be largely undisturbed by the project except for the removal of four of the aspens which were assessed by the arborist as being in poor health. D. Wildlife Use of Project Vicinity Despite all the modifications to the Sammamish River and the current degraded state of the channel, riparian zone and floodplain, the river still supports several listed species. The Washington Department of Fish & Wildlife (WDFW) Priority Habitats and Species (PHS) Report for the property lists 8 priority fish species that may utilize the Sammamish River during some portion of their life cycle. These are listed below in Table 1 along with other priority species with a potential to be present in the project vicinity. EXHIBIT I ---PAGE BREAK--- Hopelink Redmond Integrated Service Center Mitigation Monitoring Report Redmond, Washington October 2016 PBS Project: 41342.001 5 Table 1. Priority Species with a Potential Presence in the Vicinity of the Property Species Federal Status Critical Habitat State Status Occurrence Type Coastal-Puget Sound Bull Trout Salvelinus confluentus Threatened Yes species of concern no recent documentation Puget Sound Chinook Salmon Threatened Yes species of concern breeding / occurrence Puget Sound Steelhead mykiss Threatened Proposed none Infrequent occurrence Puget Sound / Strait of Georgia Coho Salmon kisutch Candidate none rearing / occurrence Kokanee (non-migrating sockeye) nerka Proposed priority occurrence / migration Sockeye salmon nerka Not Warranted priority occurrence / migration Resident Coastal Cutthroat clarki priority occurrence / migration Rainbow trout mykiss priority occurrence / migration Bald Eagle Haliaeetus leucocephalus sensitive species occasional presence Pileated Woodpecker Dryocopus pileatus species of concern possible occurrence Great blue heron (Species of Local Importance) Ardea herodias probable occurrence Purple martin Progne subis candidate general vicinity Lake Sammamish The Sammamish River historically supported large runs of most of the native salmonid species which migrated up from Lake Washington to spawn in the Sammamish River and Lake Sammamish tributaries. Now most of the stocks are seriously depleted due to habitat loss and degradation. Most of the listed salmonids that have a presence in the Sammamish River primarily use the project area reach as a migratory route to upstream creeks, which at the project location would be Bear Creek, Issaquah Creek and a couple of smaller streams. Many of the salmonids that use this stretch of river are reared in a hatchery in Issaquah that releases Coho and Fall Chinook salmon. Limited rearing of juveniles may occur in the river. The most serious limiting factor to salmonid use is temperature, but other limiting factors include degraded riparian conditions and lack of off-channel areas. In addition to the species listed above, The Sammamish River provides habitat for a large variety of fish and wildlife species. Other native fish species identified in the river include sculpin, pike minnows, sticklebacks, longnose dace, suckers and lamprey. Non- native fish are also present and include large- and small-mouth bass, yellow perch, bullhead, sunfish and carp (Tetratech, 2002). Ducks, geese and other waterfowl are common on the river, particularly at the project location since people regularly feed them under the bridge. There are also a variety of other birds present along the river. There is very little habitat for amphibians at this location because of the relatively steep banks and lack of shallow ponding habitat and wetlands. EXHIBIT I ---PAGE BREAK--- Hopelink Redmond Integrated Service Center Mitigation Monitoring Report Redmond, Washington October 2016 PBS Project: 41342.001 6 Most of the mammal species that would utilize the river at this location would be those tolerant of human activity such as deer, raccoon, coyotes, possums, skunk, rabbits, shrews, mice and voles. We observed beaver activity along the river in the form of chewed stumps. Wildlife use on the subject property is likely limited to small mammals and birds given the urban location and the King County trail. E. Buffer Characterization King County Parks owns a 100 foot wide parcel on either side of the river at the project location. On the west side of the river, the King County parcel contains a utility easement and the West Sammamish River Trail. While this trail does not receive the same level of use as the Sammamish River Trail on the east side of the river, it still has a fair amount of pedestrian and bicycle use and there is unofficial access to the river at several points. Some camping by the homeless occurs along this side of the river. Most of the King County 100 foot wide parcel was planted in 2002 and the planted trees are now about 15 to 20 feet tall and shrubs have expanded to cover much of the area. The bitter cherry has spread in some areas to form dense thickets. Some vegetation in the riparian corridor predates the restoration. There is a grove of black cottonwoods that are up to 3 or 4 feet in diameter and 60 to 70 feet tall on the King County property near the border with the subject property. There are also 4 giant sequoia (Sequoiadendron giganteum) trees just south of the bridge on the west side of the river that are approximately 20 inches in diameter. Figure 4 shows the existing vegetation cover types on the project site and adjacent King County parcel. The ability of the riparian corridor/stream buffer at this location to provide natural functions is limited by the urban context, narrow width, high use trails, steep banks and lack of structural diversity. Table 2 lists the identified riparian functions with an assessment of the level of this function at the project site vicinity. Table 2. Riparian Corridor Functional Assessment Function Level of functioning Shade & Temperature Low - Shade is improving in this reach as the plantings mature, but is still rather limited. Less than 1 percent of the channel at the project location is shaded. There is not much opportunity for temperature moderation. Flood conveyance Moderate - The river rarely overtops its banks because of the dredging which lowered the river elevation relative to the floodplain. Most flooding would be contained between the two trails. However, a large flood event is projected to extend well beyond the riparian corridor. Water quality protection Low – Some filtering of runoff from trails and other surfaces may occur, but given the urban context and high public use, the narrow, disturbed riparian corridor probably is not able to provide much in the way of water quality protection to the river at this location. High use by dogs, homeless people and concentrations of ducks would act to reduce water quality. Most stormwater runoff is directed straight into the river with little or no treatment. Pollutant removal Low – Very little of the riparian zone actually interacts with the river because of the steep banks. There are no wetlands at this location above OHW. Most stormwater runoff is directed straight into the river. Very limited opportunity to remove pollutants EXHIBIT I ---PAGE BREAK--- Hopelink Redmond Integrated Service Center Mitigation Monitoring Report Redmond, Washington October 2016 PBS Project: 41342.001 7 Sediment transport Moderate – The riparian zone in this reach likely contributes sediment from erosion but deposition would be limited by the steep banks. Some opportunity for sediment deposition was created during the 2012 restoration with the addition of gravel bars. Bank stabilization Moderate - The new plantings are functioning to help stabilize the banks, but the west bank is steep with some evidence of erosion. Woody debris recruitment Low – The plantings are still too young to provide woody debris recruitment. The few larger cottonwoods in the buffer are likely too far from the river to contribute much if they fell down. Wildlife habitat Low – High public use, narrow corridor, urban context, and lack of structural diversity limit wildlife use. While the river provides a travel corridor, there are no large habitat areas in the immediate vicinity. The riparian corridor does provide habitat for a variety of birds, waterfowl, and small mammals adapted to human presence. It likely provides a refuge within the urban context. Microclimate control Low to moderate– Improving as plantings mature but still relatively low F. Water Quality Currently all stormwater runoff from the site flows directly into the Sammamish River with no flow control or water quality treatment. The project will decrease impervious surface, removing all impervious surface in the buffer. Stormwater runoff from the parking areas will be treated in several bio-retention cells before discharge to the river. The project should result in an overall improvement in water quality. III. PROPOSED MITIGATION SITES Approximately 32% of the river buffer on the subject parcel is currently occupied by one of the existing office buildings and another 18 percent by sidewalks. Impervious surfaces cover 50% of the Fish and Wildlife Conservation Area on the property. The project proposes removal of these structures from the buffer. The mitigation site will be the same as the impact site, but will extend beyond the 150 foot regulated buffer. Restoration will occur on 3,750 square feet of area where pavement and building foundations are removed in the buffer area and some landscaped areas are removed. A new gravel trail will occupy approximately 650 square feet. By restoring this area, the project will remove a nonconforming use and restore functioning to the outer portion of the buffer. The project will enhance through weed control and some plantings an additional 3,400 square feet of existing vegetated buffer. The boundaries of the restoration and enhancement areas are shown on Mitigation Plan Sheet M.1.00. IV. EXISTING BASELINE CONDITIONS OF MITIGATION SITE The mitigation site is the same as the impact site so conditions are the same. Refer to Section II for a description of existing conditions. EXHIBIT I ---PAGE BREAK--- Hopelink Redmond Integrated Service Center Mitigation Monitoring Report Redmond, Washington October 2016 PBS Project: 41342.001 8 V. MITIGATION APPROACH A. Mitigation Sequencing The standard mitigation sequencing does not really apply to this project as there are no impacts to critical areas or buffers. The development removes infrastructure and impervious surface from a habitat conservation area buffer along the Sammamish River and provides water quality retention and treatment. Mitigation is occurring on-site and in- kind at the same location as the impact and will result in an improved buffer condition. B. Project Specific Goals The goal of the restoration will be to restore natural riparian corridor functioning to the extent possible given the urban context, and to provide an incremental increase in available habitat for species using the buffer along the Sammamish River. It is not generally possible to recreate a fully functioning buffer in an urban environment. C. Mitigation Strategy The strategy is simply to remove the infrastructure, amend the soil, plant native species and maintain the area through initial irrigation, regular weed control and contingency measures as needed. A native plant community will replace that portion of the buffer that was occupied by an office building and sidewalk. The existing vegetated portion of the buffer will be enhanced through weed control and a few additional plantings. D. Specific Goals, Objectives and Performance Standards The ability of the mitigation site to perform a high level of functioning is limited by the small size and scale of the mitigation, the urban context, past history and existing neighboring land uses. The goal of the mitigation is to provide an improvement over the existing condition that meets the intent of the RZC to the extent possible given the above mentioned constraints. Specifically, the objective of the restoration area is to establish a self sustaining native plant community that provides habitat for local species and increases the functional width of the buffer. The goal of the enhancement portion of the mitigation is to improve habitat value and buffer functioning through an increase in native shrub cover and removal of non-native weed species. The following performance standards for stream buffers and habitat conservation areas as listed in the RZC 21.64.020F&G were applied to the design of this mitigation project. Table 3. City of Redmond Performance Standards Applied to Mitigation Applicable City of Redmond Performance Standards for Riparian Buffers and Habitat Conservation Areas How Mitigation Plan Meets These Standards 1 Use plants indigenous to the region All specified plant materials are native to this area 2 Plants should be commercially available from local sources All specified plant materials are readily available 3 Plants should be high in food and cover value for fish and wildlife Planting plan includes species with high food and cover value 4 Plant perennial species All specified plant materials are perennial 5 Use species that are known to be capable of successful establishment All specified plant materials are known to be easy to establish 6 Substrate should consist of a minimum of one foot depth of clean inorganic/organic materials Restored area will be amended with 1 foot of topsoil. Three to four inches of mulch will be applied to all planting areas EXHIBIT I ---PAGE BREAK--- Hopelink Redmond Integrated Service Center Mitigation Monitoring Report Redmond, Washington October 2016 PBS Project: 41342.001 9 7 Plant densities should be based on criteria in Appendix 1 Plant densities have been adjusted to match the anticipated size of planted species. Spacing averages 3.5 ft on center. 8 Install an irrigation system for the initial establish period Irrigation will be installed as part of the landscape irrigation for the site. 9 Construction management should occur by a qualified consultant and inspected by the City Inspections by the consultant and/or City will occur prior to planting, during planting and at the end of planting. 10 Limit the use of pesticides near streams. No pesticides will be allowed in the Mitigation Area 11 Consolidate habitat and vegetated open space in contiguous blocks The Mitigation Site is consolidated along the east edge of the property 12 Locate habitat contiguous to other habitat to contribute to a continuous system or corridor to provide connections to adjacent habitat The Mitigation Site is contiguous with the King County enhanced buffer along the Sammamish River 13 Use native species in enhancement of buffers All species being planted in the buffer are native 14 Emphasize heterogeneity and structural diversity of vegetation The planting plan includes structural diversity. Heterogeneity of plant material is limited in favor of ease of establishment. 15 Preserve significant trees, preferably in groups Native significant trees in buffer to be preserved Table 4 lists measurable performance standards and success criteria for both the restoration area and the enhancement area. These success criteria will be used to evaluate the success of the mitigation. Table 4. Performance Standards and Success Criteria Performance Standard Measure Success Criteria Restoration Area Year 1 Year 3 Year 5 Survival of Planted Stock 100% 90% 80% Percent Cover Native Trees & Shrubs 20% 30% 50% Percent Cover Invasive Species1 Percent Cover Non-native Species2 <10% <20% Enhancement Area Year 1 Year 3 Year 5 Survival of Planted Stock 100% 90% 80% Percent Cover Native Trees & Shrubs 60% 80% 80% Percent Cover Invasive Species1 Percent Cover Non-native Species2 <25% <25% <20% 1. Includes Himalayan blackberry, Japanese knotweed, English holly, thistles, bindweed, reed canary grass, common hawthorn, butterfly bush or any other species identified by King County or City of Redmond as invasive 2. Allows for some cover by non-native grass species. EXHIBIT I ---PAGE BREAK--- Hopelink Redmond Integrated Service Center Mitigation Monitoring Report Redmond, Washington October 2016 PBS Project: 41342.001 10 VI. MITIGATION DESIGN The portion of the Fish and Wildlife Conservation area that was occupied by the office building and sidewalk will be restored by removing the concrete sidewalk, building and foundation, amending the soil and planting with native species. These measures will effectively increase the width of the stream buffer at this location by 20 feet or 13 percent over the existing condition, and provide the full 150 feet of buffer. The total mitigation area measures 8,100 square feet (0.186 acre). This includes 3,550 square feet (0.08 acre) of existing vegetated buffer to be enhanced, 3,900 square feet (0.09 acre) of newly restored buffer area, and 650 square feet (0.015 acre) of new trail. The trail will connect to the existing King County trail and is designed to meet the requirements under RZC 21.64.020 B9c for trails in buffer areas. Prior to demolition temporary fencing will be installed at the edge of the sidewalk to protect the existing vegetation in the enhancement area. After removal of the structures from the restoration area, the site will be graded to elevation 33. The area will be amended with 1 foot of topsoil to bring the final grade to elevation 34 to match existing grades. No site work will occur in the enhancement area except the removal of five aspen trees (Populus tremuloides) that were deemed unhealthy by the project arborist. The location of these five trees is shown on Mitigation Plan Sheet M1.00. Table 5 lists species to be planted in the restored buffer. These species were chosen based on their suitability to the site, ease of establishment, reference plant lists, and habitat value. The planting plan also had to meet the City of Redmond screening requirements for parking lots, which influenced the choice and placement of plantings. The planting plan for the restored areas is shown on Mitigation Plan Sheet M1.01. Three to four inches of bark or wood mulch will be applied to the entire restoration area following planting to help keep weeds from becoming established, prevent erosion and help maintain soil moisture. Irrigation will be installed as part of the site landscaping. Much of the enhancement area has a well established native plant community, most of which was planted. Shrubs have filled in much of the north half of the enhancement area, but are somewhat sparse in the south half, which is dominated by grasses. The plan for the enhancement area is to increase the shrub and fern density in the southern half of the area and to replace the aspens that are being removed with vine maples. Table 6 lists the species to be planted in the enhancement portion of the buffer. Prior to planting in this area existing grasses will be removed from a three foot diameter circle prior to planting. Mulch will be applied following planting to the three foot circles around the new plants. The locations of the new plantings in this area should be adjusted to avoid damage to desirable native volunteers. The goal is to fill in the gaps and increase shrub cover and diversity. Volunteer native species will be allowed to colonize both the restored area and the enhancement area as long as they do not jeopardize the success of the restoration/enhancement. The percent cover of native volunteers will be included in determining success criteria for native plant cover. Alders, cottonwoods and aspens are likely to become established and may need to be thinned. Signs will be posted in at least two locations to inform the public that the area is part of a Fish & Wildlife Conservation area. While the RZC suggests that a split rail fence be installed along the edge of the buffer, the project is not proposing installation of a fence EXHIBIT I ---PAGE BREAK--- Hopelink Redmond Integrated Service Center Mitigation Monitoring Report Redmond, Washington October 2016 PBS Project: 41342.001 11 at this time. Temporary plastic fencing will be in place during the initial plant establishment phase (Year If yearly monitoring shows excessive trampling or trash, a permanent fence may be installed at a later date. Table 5. Density Calculation for Restored Buffer Spacing Multiplier Planting Area Square Feet Number of Plants 4 feet (approx) 0.0725 3,900 283 Table 6. Planting Plan for Restored Buffer Area Common Name Species Type1 Number Container Height Spacing TREES Douglas fir Pseudotsuga menziesii E 4 5 gallon 6-8’ ~30’ Western red cedar Thuja plicata E 8 5 gallon 6-8’ Scouler’s willow Salix scouleriana D 6 5 gallon2 3-4‘ 6’ oc Subtotal Trees 18 SHRUBS Serviceberry Amelanchier alnifolia D 6 2 gallon 10’ oc Western hazelnut Corylus cornuta D 10 2 gallon 6’ oc Red elderberry Sambucus racemosa D 22 2 gallon 3-4’ oc Snowberry albus D 43 2 gallon 3-4’ oc Dwarf rose Rosa gymnocarpa D 77 2 gallon 3-4’ oc Evergreen huckleberry Vaccinium ovatum 47 3-4’ oc Subtotal Shrubs 205 FERNS Western swordfern Polystichum munitum E 60 1 gallon 4’ oc Subtotal Ferns 60 TOTAL 283 1. E= Evergreen, D= Deciduous 2. Use 5 gallon if available, use 2 gallon if not. OC = on center Table 7. Planting Plan for Enhancement Area Common Name Species Type1 Number Container Height Spacing SHRUBS Vine maple Acer circinatum D 5 2 gallon 3-4’ 10’ oc Western hazelnut Corylus cornuta D 1 2 gallon 24” min 6’ oc Red elderberry Sambucus racemosa D 3 2 gallon 24” min 3-4’ oc Snowberry albus D 6 2 gallon 24” min 3-4’ oc Dwarf rose Rosa gymnocarpa D 4 2 gallon 24” min 3-4’ oc Subtotal Shrubs 19 FERNS Western swordfern Polystichum munitum E 5 1 gallon 4’ oc Subtotal Ferns 5 TOTAL 24 1. E= Evergreen, D= Deciduous EXHIBIT I ---PAGE BREAK--- Hopelink Redmond Integrated Service Center Mitigation Monitoring Report Redmond, Washington October 2016 PBS Project: 41342.001 12 VII. IRRIGATION PLAN Irrigation will installed as part of the landscaping of the property in the restoration portion of the mitigation site and will be used as needed to ensure the survival of the planted stock. Irrigation may be discontinued or significantly reduced after 3 years if plants are well established. Mitigation Plan Sheet M1.02 shows the irrigation layout. VIII. MONITORING PLAN Baseline monitoring will be conducted once planting is complete with the report submitted to the City within 30 days. The baseline monitoring will document the location of all planted stock. It will also serve to set up protocols for follow-up monitoring. Because the area is so small, the entire area can be monitored and all planted stock assessed. The restored area will be divided into four quadrants to make estimation of percent cover easier. The edges of the quadrants will be marked in a way that they can be easily relocated. Percent cover by strata and species will be estimated for each quadrant. Photo points will be established at each of the four quadrants to provide a representative view of that portion of the restored area. See Sheet M1.02 for location of quadrants and photo points. The site will be monitoring yearly for five years to ensure success of the plantings and to make sure that performance standards are being met. The first year monitoring will occur in early spring following planting and again at the end of the summer. Subsequent monitoring will occur yearly at the end of summer before leaf senescence. Reports are due to the City before the end of the calendar year. The monitoring will evaluate planted species survival and vigor, and percent cover of all species as specified in Table 4. It will also document any observations related to condition of the plant material, site conditions, impacts and. Contingency measures will be triggered if the success criteria are not being met or if other conditions warrant action. 1. Baseline Monitoring The following activities will be part of the baseline monitoring  Establish monitoring zones as shown on Mitigation Plan Sheet M1.02 using wooden stakes to mark the boundary between Zones A and B and between Zones C and D.  Establish permanent photo points using wooden stakes  Tally all planted species in each Zone and each tree greater than 3 feet tall in Zones C and D.  Note health and vigor of planted stock  Verify that mulch has been applied as specified and that irrigation is functioning properly  Notify the project manager immediately of any discrepancies in number, size or general spacing of planted individuals or of any plants that appear to have poor vigor.  Estimate percent cover of all species in each zone  Take photos at photo points as shown. Take at least one panoramic photo of the restoration area.  Prepare a modified site plan that shows any changes between the mitigation design and the as-built condition. EXHIBIT I ---PAGE BREAK--- Hopelink Redmond Integrated Service Center Mitigation Monitoring Report Redmond, Washington October 2016 PBS Project: 41342.001 13 2. Monitoring Years 1 through 5 The following activities will be part of the yearly monitoring in years 1 through 5.  Tally all planted species in each Zone in Years 1,2 and 3. Calculate mortality and percent survival. After Year 3, percent cover is more important than actual survival.  Estimate percent cover of all species in each zone, including existing vegetation, native colonizers and non-native or invasive species  Describe general appearance of planted stock noting any lack of vigor, water stress, browsing, or insect damage.  Compare survival and percent cover to success criteria in Table 3.  Note any mortality of existing trees in Zones C and D.  Note any evidence of trampling or trash in each zone.  Note any evidence of wildlife use including scat, browsing, nests, sightings, etc.  Take photos at established photo points as shown on the monitoring plan  Evaluate irrigation effectiveness  Note volunteer native shrubs and trees in each zone  Prepare a monitoring report that includes the above information and makes recommendations regarding contingency measures. IX. MAINTENANCE AND CONTINGENCY PLAN Following planting a temporary fence will be installed at the edge of the parking lot to protect the new plantings. The fence can be removed after the first year if plants are established. Weeding will occur at least three times annually during the 5 year establishment period. Weeding should be done in spring, mid-summer and at the end of the growing season. At each weeding, all invasive species will be removed through hand pulling. As much of the root should be removed as possible. Weeds should be bagged, removed from the site and disposed in a proper waste disposal receptacle. No herbicides, pesticides or fertilizers shall be used in the Mitigation area without the written approval of the consultant or the City of Redmond. Herbicides will only be used as a last resort and with permission of the City of Redmond planning department. Other non- native species will be removed if they are threatening the success of the plantings. Target weeds are listed in Table 7 below. Table 7. Noxious Weeds to be Targeted at Mitigation Site Scientific Name Common Name King County Noxious Weed Designation Rubus Armeniacus Himalayan blackberry Class C Noxious Weed Rubus lacinatus Evergreen blackberry Class C Noxious Weed Phalaris arundiancea Reed canary grass Class C Noxious Weed Prunus Laurocerasus Cherry laurel Weed of Concern Hedera helix English ivy Class C Noxious Weed Ilex aquifolium English holly Weed of Concern Convolvulus arvensis Field bindweed Class C Noxious Weed Cirsium vulgare Bull thistle Class C Noxious Weed EXHIBIT I ---PAGE BREAK--- Hopelink Redmond Integrated Service Center Mitigation Monitoring Report Redmond, Washington October 2016 PBS Project: 41342.001 14 Cirsium arvense Canada thistle Class C Noxious Weed Senecio jacobaea Tansy ragwort Class B Noxious Weed Polygonum cuspidatum Japanese knotweed Class C Noxious Weed Cytisus scoparius Scotch broom Class C Noxious Weed Buddleia davidii Butterfly bush Class C Noxious Weed Crataegus monogyna English hawthorn Class C Noxious Weed Leucanthemum vulgare Oxeye daisy Class C Noxious Weed Contingency measures are triggered by the yearly monitoring. The measures are intended to ensure that the project meets the stated project targets and performance standards at the end of the monitoring period. The monitoring reports will contain a section on recommended contingency measures. The City will review the monitoring reports and recommended contingency measures and work with the applicant and consultant to refine and approve all contingency measures before they are implemented. Contingency measures could include additional plantings to replace mortality, additional weed control, thinning of volunteer species, changes to irrigation regime, or other measures. Recommended contingency measures include replacement of all planted stock that dies during the first three years either in kind or with another native species that provides similar habitat value. After three years, it may not be necessary to replace mortality if desired cover levels are being met. Replacement plantings should be conducted in the next planting window (fall or early spring). If native volunteers are coming in so thick that they crowd out the planted species, thinning may be undertaken to achieve a desirable spacing. If human impacts to the mitigation area are resulting in damage to the plants, a fence may need to be installed at the edge of the parking lot. The City may require additional mitigation measures at its discretion to ensure the success of the mitigation site. EXHIBIT I ---PAGE BREAK--- Hopelink Redmond Integrated Service Center Mitigation Monitoring Report Redmond, Washington October 2016 PBS Project: 41342.001 15 X. REFERENCE City of Redmond Municipal Code: 2016. Accessed online at: http://www.codepublishing.com/WA/redmond.html City of Redmond website. 2016 Accessed online at: http://www.ci.redmond.wa.us/Environment King County, WA. 2012. Critical Areas Mitigation Guidelines. Access online at: http://www.kingcounty.gov/~/media/depts/permitting-environmental- review/dper/documents/forms/ls-not-samit-pdf.ashx?la=en King County, WA. 2016. King County Noxious Weed List. Accessed online at: http://www.kingcounty.gov/environment/animals-and-plants/noxious- weeds/laws/list.aspx NRCS Web Soil Survey. 2015. Accessed on-line at: http://websoilsurvey.nrcs.usda.gov/app/WebSoilSurvey.aspx Pojar J. and A. MacKinnon. 2004. Plants of the Pacific Northwest Coast - Revised. Lonepine Publishing Tetra Tech, Inc. 2002. Sammamish River Corridor Action Plan. Accessed online at http://your.kingcounty.gov/dnrp/library/2002/kcr1270/02_Chapter_2.pdf USDA Natural Resources Conservation Service. 2015. Plants National Database. Accessed online at: http://plants.usda.gov/java/ USDA Natural Resources Conservation Service. 2015. Web Soil Survey. Accessed online at: http://websoilsurvey.nrcs.usda.gov/app/WebSoilSurvey.aspx USDA. 2005 Soil Series Descriptions. Snohomish Series. Accessed online at: http://soilseriesdesc.sc.egov.usda.gov/OSD_Docs/S/SNOHOMISH.html Washington Department of Fish and Wildlife (WDFW). 2015. Salmonscape Mapper. Accessed online at: http://fortress.wa.gov/dfw/gispublic/apps/salmonscape/default.htm Washington Department of Fish and Wildlife (WDFW). 2015.Priority Habitats and Species on the Web. Accessed online at: http://apps.wdfw.wa.gov/phsontheweb/ WTU Herbarium Image Collection. 2015. Burke Museum of Natural History and Culture. Accessed online at: http://biology.burke.washington.edu/herbarium/imagecollection.php EXHIBIT I ---PAGE BREAK--- FIGURES EXHIBIT I ---PAGE BREAK--- Hopelink Redmond Integrated Service Center Mitigation Monitoring Report Redmond, Washington October 2016 PBS Project: 41342.001 17 Project Site N Project # 41342.000 May 2016 SITE VICINITY MAP Hopelink Redmond Integrated Service Center Redmond, Washington FIGURE 1 EXHIBIT I ---PAGE BREAK--- Hopelink Redmond Integrated Service Center Mitigation Monitoring Report Redmond, Washington October 2016 PBS Project: 41342.001 18 N Project # 41342.000 May 2016 PROPOSED SITE PLAN Hopelink Redmond Integrated Service Center Redmond, Washington FIGURE 2 KEY 150’ Stream buffer 200’ Shoreline zone Building Pollution generating surfaces Site landscaping Bio-retention cells Existing native vegetation berm Restored buffer area EXHIBIT I ---PAGE BREAK--- Hopelink Redmond Integrated Service Center Mitigation Monitoring Report Redmond, Washington October 2016 PBS Project: 41342.001 19 Project Site N Project # 41342.000 May 2016 IMPACT & MITIGATION AREAS Hopelink Redmond Integrated Service Center Redmond, Washington FIGURE 3 N NE 90th St. Sammamish River IMPACT AND MITIGATION AREAS 150’ Class 1 River Buffer 200’ Shoreline Zone Impact Area- Remove building, sidewalk & asphalt Restoration Area – New plantings Enhancement Areas – Weed control, new plantings EXHIBIT I ---PAGE BREAK--- Hopelink Redmond Integrated Service Center Mitigation Monitoring Report Redmond, Washington October 2016 PBS Project: 41342.001 20 Project # 41342.000 May 2016 EXISTING VEGETATIVE COVER TYPES Hopelink Redmond Integrated Service Center Redmond, Washington FIGURE 4 See cover type descriptions in text Trees were only surveyed west of the King County Trail. 150’ Stream Buffer TREES: Sequoia Cottonwood Douglas-fir Aspen Hemlock Big-leaf maple Red maple VEGETATION COVER TYPES KC buffer plantings KC riparian plantings Site native plantings Cottonwood forest Aspen grove Landscaping West Sammamish River Trail N Ordinary High Water EXHIBIT I ---PAGE BREAK--- Hopelink Redmond Integrated Service Center Mitigation Monitoring Report Redmond, Washington October 2016 PBS Project: 41342.001 21 Project # 41342.000 May 2016 MITIGATION PLANTING PLAN Hopelink Redmond Integrated Service Center 15517 NE 90th St. Redmond, Washington FIGURE 5 Existing Native Shrubs Existing Native Shrubs See Sheet M1.01 for details Trees 4 Douglas-fir 8 Western red cedar 6 Scouler’s willow Ferns 65 Swordfern Shrubs 5 Vine maple 5 Serviceberry 11 Western hazelnut 25 Red elderberry 49 Snowberry 81 Dwarf rose 47 Evergreen huckleberry CONCEPTUAL PLANTING PLAN EXHIBIT I ---PAGE BREAK--- APPENDIX A Site Photographs EXHIBIT I ---PAGE BREAK--- Hopelink Redmond Integrated Service Center Mitigation Monitoring Report Redmond, Washington October 2016 PBS Project: 41342.001 23 Photo 1. View to north of east edge of parcel with existing building, sidewalk and planted berm with swordferns in the foreground and Douglas-firs in the background. Photo 2. View to south of berm with quaking aspen seedlings in foreground and planted maple and older aspens in background. Photo 3. View of northern part of berm with planted snowberries and tall Oregon grape. Most berm plantings will be preserved. Photo 4. View to north of King County trail through stream buffer. Photo 7. Large cottonwoods at southeast corner of property to be preserved Photo 8. Birdseye view to east of buffer area in current condition EXHIBIT I ---PAGE BREAK--- APPENDIX B Mitigation Monitoring Plan Sheets EXHIBIT I ---PAGE BREAK--- EXHIBIT I ---PAGE BREAK--- EXHIBIT I ---PAGE BREAK--- EXHIBIT I