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HomeMy WebLinkAboutRS_PN_CM_Shoreline Permit Application Report_181018_v1 Shoreline Permit Application Report Shoreline Permit Application Report May Creek Trail Extension Project City of Renton Prepared for: Prepared by: Jeff Gray, PWS Stephanie Modjeski Kevin O’Brien, PhD Otak, Inc. 2731 Wetmore Avenue, Suite 300 Everett, WA 98201 October 19, 2018 Shoreline Permit Application Report October 19, 2018 May Creek Trail Extension i Acronyms and Abbreviations ................................................................................................................... iii Chapter 1. Introduction ............................................................................................................................. 4 Chapter 2. Project Narrative ..................................................................................................................... 4 Chapter 3. Construction Methods ............................................................................................................ 5 Chapter 4. Existing Conditions................................................................................................................... 6 4.1 Landscape Setting and Project Area Overview ............................................................................ 6 4.2 Wetlands ....................................................................................................................................... 6 4.3 Streams ......................................................................................................................................... 7 Chapter 5. Proposed Buffer Mitigation Plan ............................................................................................ 7 5.1 Mitigation Overview ............................................................................................................................ 7 Avoidance and Minimization ................................................................................................................. 8 5.2 Buffer Impacts ..................................................................................................................................... 8 5.3 Proposed Mitigation ............................................................................................................................ 8 5.4 Mitigation Design Criteria ................................................................................................................... 8 5.5 Wetland Buffer Mitigation Plan ........................................................................................................... 9 5.5.1 Buffer Mitigation Goals and Objectives ................................................................................. 9 5.5.2 Mitigation Timing ................................................................................................................... 9 5.5.3 Mitigation Performance Standards ........................................................................................ 9 5.5.4 Non-native Invasive Species Removal ............................................................................... 10 5.5.5 Plant Species Selection Specifications ............................................................................... 10 5.5.6 Plant Installation Specifications ........................................................................................... 11 5.5.7 Best Management Practices ............................................................................................... 11 Chapter 6. Proposed Monitoring Plan .................................................................................................... 11 6.1 Proposed Monitoring Plan ................................................................................................................ 11 6.1.1 Vegetation Monitoring Plots ................................................................................................ 11 6.1.2 Photo-points ........................................................................................................................ 12 6.1.3 Wildlife Presence................................................................................................................. 12 6.1.4 Maintenance/Contingency Observations ............................................................................ 12 6.1.5 Monitoring Schedule ........................................................................................................... 12 6.1.6 Monitoring Reporting ........................................................................................................... 13 6.2 Maintenance and Contingency Actions ............................................................................................ 13 6.2.1 Maintenance ........................................................................................................................ 13 6.2.2 Irrigation .............................................................................................................................. 13 6.2.3 Plant Replacement .............................................................................................................. 13 6.2.4 Non-native Invasive Species Control .................................................................................. 13 6.2.5 Other Maintenance Actions ................................................................................................. 14 6.2.6 Contingency Actions ........................................................................................................... 14 Chapter 7. Biological and Habitat Assessment..................................................................................... 14 7.1 ESA-Listed Species Present in Project Area ...................................................................... 15 7.2 Direct and Indirect Effects to Primary Constituent Elements of Listed Species.................. 15 Shoreline Permit Application Report October 19, 2018 May Creek Trail Extension ii 7.3 Direct and Indirect Effects to Other Listed Species ............................................................ 17 7.4 Direct and Indirect Effects to Floodplain Functions ............................................................. 17 7.5 Cumulative Effects to Primary Constituent Elements of Listed Species and Floodplain Functions ............................................................................................................................................ 18 7.6 FEMA Floodplain Habitat Assessment Effect Determination .............................................. 18 7.7 Project Applicant Contact Information ................................................................................. 18 7.8 Fieldwork Dates and Report Author Qualifications ............................................................. 18 Chapter 8. References ............................................................................................................................. 20 Appendix A — Critical Areas Memo and Photo-log ............................................................................ 21 Appendix B — WSDOT Wetland and Stream Assessment Report ........................................................ 22 Appendix C — Neighborhood Detail Map ............................................................................................ 23 Shoreline Permit Application Report October 19, 2018 May Creek Trail Extension iii Acronyms and Abbreviations City City of Renton BMPs Best Management Practices DU/AC Dwelling Unit per Acre Ecology Washington State Department of Ecology HPA Hydraulic Project Approval I-405 Interstate 405 NRCS Natural Resources Conservation Service OHWM Ordinary high water mark Otak Otak, Inc. RC Resource Conservation RLD Residential Low Density RMC Renton Municipal Code RMD Residential Medium Density TESC Temporary Erosion and Sediment Control USACE U.S. Army Corps of Engineers WDFW Washington State Department of Fish and Wildlife WDNR Washington Department of Natural Resources WRIA Water Resource Inventory Area WSDOT Washington State Department of Transportation Shoreline Permit Application Report October 19, 2018 May Creek Trail Extension iv Chapter 1. Introduction The City of Renton (City) is proposing the May Creek Trail Extension Project (Project). The project will construct a pedestrian trail extension from the existing May Creek Trail west of Interstate-405 (I-405) to Jones Avenue NE and will be folded into I-405 - Renton to Bellevue Widening and Express Toll Lanes project under the Washington Department of Transportation (WSDOT). Otak, Inc. (Otak) is contracted by the City to provide permitting support for the proposed Project. The Project is located within a designated shoreline environment and requires a Shoreline Permit compliance per the City of Renton. This report documents the environmental permitting requirements associated with the proposed Project. Chapter 2. Project Narrative The Project is located in the City of Renton, King County, Washington. The Project includes parcels #3224059109 and #3224059010 and is located in Section 32, Township 24, Range 05 East of the Public Land Survey System, and in Water Resource Inventory Area (WRIA) 8-Cedar Sammamish. May Creek is a tributary to Lake Washington. Lake W ashington is located approximately 0.32 mile west of the Project site. Site elevation is approximately 50 feet above mean sea level and has a mild slope west toward the existing May Creek Trail. Land use in the vicinity is single-family residences, the I-405 corridor, green space, and the existing May Creek Trail. The trail extension will extend underneath the Interstate-405 (I-405) overpass along the north side of May Creek from the existing May Creek Trail to Jones Avenue NE. For the purpose of this Shoreline Permit packet, the Project extent is from east of the I-405 overpass to Jones Avenue NE and a small portion of trail to the west of the I-405 overpass and does not include Washington State Department of Transportation (WSDOT) right of way. The trail section within WSDOT right of way beneath the I-405 overpass is being permitted separately from this Project. An informal trail exists currently in the location of the proposed trail. The proposed trail will be approximately 815 feet long and 6-feet wide and will be composed of a fine bark mulch on top of a compacted gravel borrow layer. Approximately 300 LF of the trail extension will occur within WSDOT right of way. The ordinary high water mark of May Creek is located between approximately 19 and 88 feet south of the proposed trail. May Creek is designated as a Shoreline of the State (Type S) stream per Washington Department of Natural Resources (WDNR) and the City and has a standard buffer width of 200 feet per Renton Municipal Code(RMC) 4-3-090B (Regulated Shorelines). The Project will occur above the ordinary high water mark and entirely within the 200-foot buffer of May Creek. Public hiking trails over land in the buffer are permitted as long as it does not degrade the ecological functions or natural characteristics of the shoreline area (RMC 4-3-090E.1) The current functions of the stream buffer are impeded by dense invasive cover. A large Himalayan blackberry (Rubus armeniacus) upland field is located immediately east of the I-405 underpass. The banks of May Creek are forested with a dense understory of Himalayan blackberry, knotweed (Polygonum japonica) and reed canary grass (Phalaris arundinacea). The Project intends to mitigate for impacts to the shoreline environmental by minimizing adverse impacts, restoring the affected environment, and compensating by environmental enhancement (RMC 4-3- 090D.2.a.iii). The Project includes enhancing the 200-foot wide stream buffer along the trail east of I-405 Shoreline Permit Application Report October 19, 2018 May Creek Trail Extension 5 by removing invasive plants and restoring the native riparian vegetation community between May Creek and the new trail. Enhancements will extend from the I-405 right-of-way westward to approximately 70 feet from the edge of Jones Avenue NE. Proposed buffer enhancement actions include removing the invasive plants, supplemental planting in the existing understory to increase native plant diversity and restoring native forest habitat. Approximately 1/3 acre is proposed for buffer enhancement. No wetlands are located within the Project area. An off-site wetland (Wetland 7.2R) is located approximately 100 feet north of the proposed trail alignment. The Natural Resources Conservation Service (NRCS) mapped soils include Norma sandy loam (poorly drained). WSDOT’s project is anticipated to begin in 2019 and end in 2024. The site is zoned R6-Residential 6 Dwelling Units per Acre (Parcel #3224059109) west of I-405 and Resource Conservation (Parcel # 3224059010) east of I-405. The site’s comprehensive plan designation is RMD-Residential Medium Density (parcel # 3224059109) and RLD- Residential Low Density (parcel #3224059010). The site is zoned R6-Residential 6 DU/AC (parcel # 3224059109) and RC- Resource Conservation (parcel #3224059010). The shoreline master program designation of the site is Urban Conservancy. Land use permits required for the proposed Project include a Shoreline Permit and clearing and grading permit from the City of Renton, and may require a hydraulic project approval (HPA) from Washington Department of Fish and Wildlife (WDFW). The Project area can be accessed via the existing May Creek Trail from the trailhead on Lake Washington Boulevard N, or via Jones Avenue NE. No off-site improvements are proposed. The Project will include approximately 17 CY of excavation for trail installation, and approximately 265 CY of fill for trail installation. Approximately 14,600 square feet of non-native invasive vegetation will be removed and replanted with native plant species for stream buffer enhancement, and will include the removal of two non-native black locust (Robinia pseudoacacia) trees adjacent to Jones Avenue NE. The total estimated construction cost and fair market value of the Project is approximately $138,000. Chapter 3. Construction Methods Transportation and access to the Project site will be from Jones Avenue NE and the existing May Creek Trail, west of I-405. Construction will occur during daylight hours, Monday through Friday. Temporary erosion and sediment control measures (TESC) and appropriate construction best management practices (BMPs) will be used during construction to minimize erosion. Potential stormwater runoff from construction activity will be intercepted by installed erosion control methods such as silt fences to prevent runoff to the adjacent stream. High visibility fencing will be installed to mark construction and clearing limits. All TESC measures will be installed prior to trail construction and buffer restoration. Spill containment measures will be properly implemented, monitored and maintained, and all equipment refueling will occur outside of buffer areas. Temporarily impacted areas will be restored with native vegetation and exposed soils will be covered during construction. No fill or excavation will take place below the ordinary high water mark of May Creek. After construction and plant installation is completed and the site has stabilized, all silt fences and any other temporary erosion protection structures will be removed. Shoreline Permit Application Report October 19, 2018 May Creek Trail Extension 6 Chapter 4. Existing Conditions 4.1 Landscape Setting and Project Area Overview The Project is located in the City of Renton, King County, Washington. The Project includes parcels #3224059109 and #3224059010 and is located in Section 32, Township 24, Range 05 East of the Public Land Survey System, in Water Resource Inventory Area (WRIA) 8-Cedar Sammamish. The Project area extent is from east of the I-405 overpass to Jones Avenue NE and includes approximately 200 feet north of the ordinary high water mark of May Creek. May Creek is a tributary to Lake Washington. Lake W ashington is located approximately 0.32 mile west of the Project site. Site elevation is approximately 50 feet above mean sea level, and has a mild slope west toward the existing May Creek Trail. Land use in the vicinity is single-family residences, the I-405 corridor, green space, and the existing May Creek Trail. The Project will occur along the north side of May Creek from west of the I-405 overpass to Jones Avenue NE. An informal dirt trail connects the existing May Creek Trail to Jones Avenue NE. The informal trail follows the north side of May Creek, beneath I-405 and extends through a large Himalayan blackberry and reed canary grass field before connecting with Jones Avenue NE. The riparian buffer of May Creek is dominated by invasive species. A large Himalayan blackberry upland field is located immediately east of the I-405 underpass. The banks of May Creek are forested with a dense understory of Himalayan blackberry, knotweed and reed canary grass. Tree species within the area include black locust (Robinia pseudoacacia), red alder (Alnus rubra), big leaf maple (Acer macrophyllum), and black cottonwood (Populus balsamifera ssp. trichocarpa). A photo-log of existing conditions within the Project area is included in the technical memorandum, May Creek Trail Extension Critical Areas Review (Otak 2018) provided in Appendix A. 4.2 Wetlands Wetland delineations were completed in the project area by WSDOT in May 2016 for the freeway widening project: I-405, Renton to Bellevue. An off-site wetland (Wetland 7.2R) is located approximately 100 feet north of the proposed trail alignment and is rated as a Category III wetland with a habitat score of 5 using the Wetland Rating System for Western Washington (Hruby 2014). WSDOT wetland delineations are described further in the Wetland and Stream Assessment Report, I-405, Renton to Bellevue Corridor Milepost 4.0-13.7 (WSDOT 2018) included in Appendix B. Biologists from Otak completed a field investigation on June 11, 2018 to verify wetland delineations and characterizations. No wetlands are located within the Project area. The southern boundary of Wetland 7.2R is located within the Urban Conservancy designated shoreline environment of May Creek. Per RMC 4-3-090D.2.d.iv a Category III wetland with moderate wildlife function points and within Shoreline Jurisdiction has a buffer width of 125 feet. Shoreline Permit Application Report October 19, 2018 May Creek Trail Extension 7 A critical areas findings technical memorandum, May Creek Trail Extension Critical Areas Review (Otak 2018) was prepared post field investigation. The findings memorandum is included in Appendix A. 4.3 Streams The ordinary high water mark (OHWM) of May Creek was delineated by WSDOT in 2016 and was verified by Otak biologists in June 2018, using previously hung flags and field indicators for OHWM. The delineated OHWM was consistent with field observations and previous mapping by WSDOT. May Creek is located south of the proposed trail alignment and flows east to west beneath the I-405 overpass. May Creek is a perennial stream and is designated a Type S (Shoreline of the State) per WDNR and the City of Renton. May Creek has a standard buffer width of 200 feet per Renton Municipal Code (RMC) 4-3-090B (Regulated Shorelines). A regulatory summary is included in the May Creek Trail Extension Critical Areas Review (Otak 2018). ESA-listed species that utilize May Creek include Puget Sound Chinook salmon (Oncorhynchus tshawytscha) Evolutionary Significant Unit (ESU) and Puget Sound/Coastal steelhead (Oncorhynchus mykiss) Distinct Population Segment (DPS), but May Creek has not been designated as critical habitat for either species. Per WDFW’s SalmonScape, other salmonid species documented within May Creek include Sockeye (Oncorhynchus nerka) and Coho (Oncorhynchus kisutch) salmon, and resident cutthroat trout (Oncorhynchus clarkii). Chapter 5. Proposed Buffer Mitigation Plan 5.1 Mitigation Overview Local, state, and federal agencies require projects impacting wetlands, streams or their buffers to follow mitigation sequencing that includes measures to avoid, minimize, restore, and compensate for unavoidable impacts. It is incumbent on the applicant to show and document mitigation sequencing before alterations are approved. Other opportunities exist for offsetting impacts to wetland buffers per Renton Municipal Code (RMC) 4-3-050I (Alterations to Critical Areas Buffers), including buffer averaging, buffer reduction with enhancement, and buffer increases. Development within buffers may be approved if one of these permitting strategies is employed, and compliance with RMC is achieved. Buffer mitigation opportunities exist in the Project vicinity. This section proposes buffer mitigation based on enhancement of on-site degraded buffers. The Project intends to mitigate for impacts to the shoreline environment by minimizing adverse impacts, restoring the affected environment, and compensating by environmental enhancement (RMC 4-3-090D.2.a.iii). Per 4-3-090F.1 (Shoreline Conservation), a vegetation conservation buffer of 100-feet is required for development projects within a designated shoreline. The Project site is located within Reach B of May Creek and requires the full standard 100-foot buffer as measured from the OHWM of May Creek. Removal of noxious weeds and invasive species is allowed within the vegetation conservation buffer area, and new development is required to develop and implement a vegetation management plan per RMC standards. Public hiking trails over land in the buffer are permitted if they do not degrade the ecological functions or natural characteristics of the shoreline area (RMC 4-3-090D2[a]) for no net loss of ecological function in a shoreline environment. Additionally, RMC 4-3-090D 4(f) specifically calls out the proposed Project to provide public access through a trail parallel to May Creek Shoreline Reach B: Shoreline Permit Application Report October 19, 2018 May Creek Trail Extension 8 “0public access should be provided consistent with standards of this Section from a trail parallel to the water along the entire property with controlled public access to the water consistent with standards of this Section, and goals of preservation and enhancement of ecological functions.” The proposed activity includes clearing of invasive species that encumber the site. The current functions of the stream buffer are impeded by dense invasive cover. Clearing within the buffer will allow native species to establish and promote natural succession of the forested area, resulting in the overall improvement of ecological functions of the site. Avoidance and Minimization Direct impacts to wetlands and May Creek have been avoided under the proposed Project design. Impacts to the wetland and stream buffer areas are unavoidable as the proposed trail extension connects to the existing May Creek Trail west of I-405, which is already located within the 200-foot stream buffer and 100-foot vegetation management buffer. Buffer impacts have been minimized by proposing a 6-foot wide trail using existing elevations and for pedestrian use only. Tree removal has been minimized to install the trail extension, and is limited to two non-native black locusts adjacent to Jones Ave. NE. The conversion of sub-canopy shrub habitat to native species will occur in stands of non-native, invasive plants. The vegetation management component of this Project includes eliminating and reducing total cover by invasive species in all forested and non-forested areas within on-site buffers and re-establishing a native forest plant community. 5.2 Buffer Impacts Approximately 3,660 square feet (0.1 acres) of vegetated stream buffer will be converted for the trail extension. The Project includes enhancing the 200-foot wide stream buffer along the trail east of I-405 by removing invasive plants and restoring the native riparian vegetation community between May Creek and Wetland 7.2R. The Wetland 7.2R buffer partially overlaps with the stream buffer. Buffer enhancements will also extend to the west edge of Jones Avenue NE. 5.3 Proposed Mitigation For shoreline compliance in achieving no net loss of functions, the enhancement of approximately 1/3 acres of existing buffer is proposed to offset the conversion of 3,660 square feet of low-functioning buffer to trail, in order to achieve an overall functional lift in the shoreline regulated area. A dense thicket of Himalayan blackberry extends from May Creek north to Wetland 7.2R with patches of Japanese knotweed and reed canarygrass in the understory near May Creek. Proposed buffer enhancement actions include removing the invasive plants, supplemental planting in the existing understory to increase native plant diversity, and restoring native forest habitat up to the boundary of Wetland 7.2R. 5.4 Mitigation Design Criteria This Plan has been designed in accordance with RMC 4-3-090D. The plan has also been designed with reference to guidelines from the US Army Corps of Engineers (USACE), Washington State Department of Ecology (Ecology) (Washington State Department of Ecology et al., 2006a. and 2006b): • Avoid: The Project has been designed to avoid impacts to critical areas and buffers to the maximum extent possible. For example, impacts to wetlands and streams are being completely avoided. • Minimize: The Project has been designed to minimize impacts to critical areas and critical area buffers to the maximum extent possible. For example, impacts to the stream and wetland buffers will Shoreline Permit Application Report October 19, 2018 May Creek Trail Extension 9 be minimized through construction best management practices such as marking clearing limits with high visibility fencing, and through temporary erosion and sediment control methods such as installed silt fences, and covering of exposed soils, refueling construction equipment outside critical area buffers. Tree removal has been minimized and consists of removal of a non-native species. • Compensate: Compensation for the permanent conversion of buffer will be provided by enhancing the remaining buffer approximately 4:1. • Monitor and Report: The mitigation area will be monitored for five years with annual monitoring reporting, including photo documentation from designated photo-points and assessment of plant survivorship and vegetated cover. 5.5 Wetland Buffer Mitigation Plan The buffer mitigation plan, including goals and objectives and the performance standards by which to assess their achievement, is included in Section 5. A five-year monitoring and maintenance plan is proposed for the buffer enhancement mitigation area. The monitoring plan in Section 6 outlines monitoring protocols and the reporting schedule to track the progress and success of the restoration areas. In Section 6, the maintenance plan includes recommendations for irrigation for at least the first two years after installation, and specifications for removal of non-native invasive species, replacement of installed plants that fail, and other activities—including contingency actions that will be taken if the restoration areas do not satisfy performance standards. This wetland buffer mitigation plan proposes several actions to enhance approximately 1/3 acre of the stream buffer, including: • Removal of non-native invasive species • Installation of native species for upland communities within the areas proposed for buffer enhancement • Install signage 5.5.1 Buffer Mitigation Goals and Objectives 1. Successfully remove invasive species from the existing wetland buffer. 2. Restore and enhance native upland vegetation within the stream buffer 3. Provide signage notifying public of sensitive mitigation area for the purpose of keeping visitors out of the mitigation area and also to educate visitors about wetlands and buffers. 5.5.2 Mitigation Timing Per RMC 4-3-050L(e.1), the proposed mitigation plan shall be submitted prior to the issuance of building or construction permits for development, and mitigation activities shall be timed to occur in the appropriate season based on weather and moisture conditions. The proposed buffer mitigation plan will be submitted with the shoreline substantial development permit, and construction of the trail and buffer mitigation planting is anticipated to occur concurrently. 5.5.3 Mitigation Performance Standards Shoreline Permit Application Report October 19, 2018 May Creek Trail Extension 10 Performance Standards are the means to quantify whether the Mitigation Goals and Objectives listed above are being met. The City of Renton requires monitoring for five years after installation (RMC 4-3- 050L.3). The following parameters will be assessed for the required monitoring period (see Section 5 Monitoring): 1) Non-native Invasive Species: • ALL YEARS: Throughout the designated planting areas, there will be less than 10 percent total aerial cover by the following non-native invasive species: non-native invasive knotweeds including Japanese, Bohemian, giant, Himalayan, and hybrids (Polygonum cuspidatum, P. bohemicum, P.sachalinense, and P. polystachyum); Himalayan blackberry; and reed canary grass. 2) Survival of Installed Shrubs: • Year 1: there will be 100 percent survival of installed shrubs due to installation warranty. • Year 2: there will be at least 80 percent survival of installed shrubs. • Year 3: there will be at least 75 percent survival of installed shrubs. 3) Percent Cover: • By Year 1: There will be at least 30 percent cover by native shrub species in the buffer mitigation area, including both installed species and desirable volunteer native species. • By Year 2: There will be at least 40 percent cover by native shrub species in the buffer mitigation area, including both installed species and desirable volunteer native species. • By Year 5: There will be at least 60 percent cover by native shrubs species in the buffer mitigation area, including both installed species and desirable volunteer native species. 4) Plant Health: • ALL YEARS: There will be visual evidence that installed plants are vigorous (e.g. new growth and few visible signs of stress). 5) Establish and Maintain Species Diversity: • Years 3-5: At a minimum, a total of five (5) native shrub species will be established in the designated planting areas. To satisfy this Performance Standard, a particular species only has to be established in the mitigation site, and desirable native volunteer species can be counted. 5.5.4 Non-native Invasive Species Removal Himalayan blackberry within the existing stream and wetland buffer shall be removed by the contractor. Removal is recommended to be completed during construction and before planting with native species. Recommended removal strategies include the following: • Removal by hand. Cut the stalks, remove the root crowns, and dispose of the plant material off-site. This control method can be implemented in the spring/summer prior to or concurrent with construction. Herbicide treatment. Cut the canes and dab a glysophate-based herbicide on the cane stump immediately after cutting. Remove the canes once dead and dispose of the plant material off-site. This control method is most successfully implemented in the fall. 5.5.5 Plant Species Selection Specifications A variety of native species are included in the buffer mitigation plan plant palette. The palette includes a total of seven native shrub species, one native deciduous tree species and two native conifer tree species. Native plant species were chosen for the following characteristics: • native to the Puget Sound area; • established presence of source populations at the Project site; Shoreline Permit Application Report October 19, 2018 May Creek Trail Extension 11 • suitable for expected site hydroperiod, light, and soil conditions; • known plant community associations; • ability to provide structural complexity, food, and shelter for wildlife; • availability from local sources; and • aesthetic appeal. Plants will be purchased from reputable regional nurseries that provide local genetic ecotypes of plants native to western Washington and the Puget Sound area. 5.5.6 Plant Installation Specifications Plants will be installed according to planting plan diagrams and schedules specified in the Mitigation Plan Sheet and the following recommendations: • Amend the designated restoration planting areas by tilling in a minimum of six (6) inches of compost into the top twelve (12) inches of soil. • The planting hole should be no deeper than the rootball, and the bottom of the rootball should rest on undisturbed soil. The planting hole should be a minimum of three (3) to four (4) times the width of the rootball. • Spread the roots and straighten circling roots as possible. • The top of the rootball should be at, or approximately ½ inch above, the soil surface. • Backfill the hole with the excavated amended soil. • Apply four (4) to six (6) inches of arborist mulch or wood chips to the designated restoration planting areas. Pull mulch four (4) inches away from stems - mulch shall not touch plant stems or trunks. 5.5.7 Best Management Practices To minimize potential impacts to critical areas and critical area buffers, best management practices (BMPs) will be followed, including strict adherence to Temporary Erosion and Sediment Control (TESC) measures during construction. BMPs include flagging all clearing limits and installing silt fences before the start of any grading activities adjacent to critical areas. After construction and plant installation is completed and the site has stabilized, all silt fences and any other temporary erosion protection structures will be removed. Chapter 6. Proposed Monitoring Plan 6.1 Proposed Monitoring Plan The purpose of monitoring is to determine whether Performance Standards are being satisfied, whether the mitigation area is being maintained properly, and if contingency actions are necessary. The mitigation areas in the reduced buffer will be monitored for a minimum of five growing seasons after the plants are installed. Monitoring visits will occur according to the schedule below. 6.1.1 Vegetation Monitoring Plots Shoreline Permit Application Report October 19, 2018 May Creek Trail Extension 12 A minimum of four permanent monitoring plots are recommended to be established to accurately reflect the conditions of the communities. Metal fence posts or other permanent markers may be installed to establish the permanent monitoring plots during the as-built site visit. It is recommended that rectangular monitoring plots be used, five meters by five meters in size. To simplify and improve accuracy of monitoring for percent survival, flag all installed shrubs within the monitoring plots when the plots are established. Maintain flagging on initially installed shrubs through at least Year 3 in order to be able to distinguish between installed woody plants and volunteers from rhizomes, seeds, etc. During each monitoring visit, data will be collected from the plots including: which species are present (including volunteers); percent aerial coverage by species; and the condition and vigor of plants. Survival of installed plants as required by Performance Standards will also be determined. In addition to presence and percent cover by non-native invasive species in the plots, their general locations and extent of cover throughout the mitigation area will be estimated and noted. General conditions of the entire buffer mitigation area, as well as the surrounding habitat, will be noted. 6.1.2 Photo-points Photographs provide an important visual record. A minimum of four permanent photo-points will be established to accurately show the vegetation and habitat status of the mitigation areas. Metal fence posts or other permanent markers will be installed to establish the photo-points. Photographs will be taken during each vegetation monitoring visit, and they will be labeled with photo station location, date, and compass bearings. 6.1.3 Wildlife Presence Wildlife presence and use of the mitigation area will be noted during the monitoring visits. The monitoring staff will record any species present, as well as wildlife indicators such as scat, prints, nests, holes, browsing marks, etc. 6.1.4 Maintenance/Contingency Observations Observations on the need for and extent of maintenance/contingency actions will be noted at each monitoring visit and reported immediately to the appropriate staff at the City of Renton. Maintenance actions may include (but are not limited to): repairing any damage from vandalism; removing trash; replacing/repairing buffer signs; augmenting irrigation; replacing mulch; weeding; removing non-native invasive species; replacing plants; etc. (see Section 6.2). 6.1.5 Monitoring Schedule Monitoring visits will occur for a minimum of five growing seasons after installation to determine whether the Performance Standards are being met. The monitoring schedule may be adjusted accordingly to match timing of the installation of mitigation plantings: • Following construction and installation of mitigation plantings. • Year 1: vegetation monitoring near the end of the growing season of the first year after installation (August/September). • Year 2: vegetation monitoring near the end of the growing season of the second year after installation (August/September). • Year 3: vegetation monitoring near the end of the growing season of the third year after installation (August/September). Shoreline Permit Application Report October 19, 2018 May Creek Trail Extension 13 • Year 5: vegetation monitoring near the end of the growing season of the third year after installation (August/September). 6.1.6 Monitoring Reporting Monitoring reports will be submitted after each monitoring visit to the City of Renton, and other agencies as required by permit conditions. These reports will describe the conditions on site, the level of success of the mitigation plan in satisfying the Performance Standards, whether contingency actions are warranted, and recommended maintenance actions. The reports will include: data collected on plant species present, and their percent cover and vigor; survival of installed plants and probable causes for any losses; percent cover by non-native invasive species; photographs from the permanent photo-points; wildlife usage of the restored areas; a list of recommended maintenance actions; and observations of general site conditions. A final monitoring report shall be submitted to the City of Renton for review upon completion of the mitigation activities in Year 5 and will include the specifications as outlined in RMC 4-3-050L. 6.2 Maintenance and Contingency Actions 6.2.1 Maintenance The designated mitigation planting areas will be maintained for a minimum of five growing seasons after installation. Maintenance activities are specified below, but generally, maintenance will include irrigating, removing non-native invasive species, replacing mulch, and installing plants as necessary to achieve the Performance Standards. Maintenance will also include replacing/repairing buffer signs, repairing the fence, removing trash, etc. 6.2.2 Irrigation Watering is critical for plant survival and establishment, especially at planting time and for at least the first summer after installation. If possible, all plantings in the designated mitigation planting areas should be watered at a rate of at least one inch per week during the dry season (approximately June through September) for the first year after installation. Under especially hot and dry conditions, the plantings may require more water. Any replacement plants installed subsequent to the initial installation, or plants that are installed in the designated restoration planting areas as the result of maintenance or contingency actions, will require irrigation until they become established. Watering frequency may be tapered off during the second year after installation. If installed, temporary irrigation systems may be removed after Year 2. 6.2.3 Plant Replacement Plants will be replaced or additional plants will be installed as required to satisfy Performance Standards for percent survival, percent cover, and vigor in the designated mitigation planting areas. Plant species appropriate to the conditions will be selected from the mitigation plan plant palette. 6.2.4 Non-native Invasive Species Control The non-native invasive species listed in the Performance Standard will be controlled throughout the designated restoration planting areas. At a minimum, control efforts will satisfy the Performance Standards of either no cover or less than 10 percent cover for the specific species. Control will occur a minimum of two times per year (in the spring and late summer) for Years 1 through 5. More frequent Shoreline Permit Application Report October 19, 2018 May Creek Trail Extension 14 maintenance will prevent non-native invasive species from becoming established (or re-established in the case of Himalayan blackberry and reed canary grass). Invasive plants (including roots and crowns) will be removed by hand or with manual tools. All cut and pulled non-native vegetation will be removed from the mitigation area and disposed of properly offsite. If manual control methods prove to be ineffective for certain species (e.g. Japanese knotweed, Himalayan blackberry, etc.), herbicide use may be necessary. Only herbicides approved for use in or near aquatic areas (e.g. Rodeo®, AquaMaster) may be used, and only licensed applicators with endorsements for aquatic pest control shall apply herbicides. Herbicide application methodologies should be those recommended by the City Renton. Application techniques include: cutting the invasives and dabbing stems; foliar wiping; etc. Stem injection is not recommended. The least amount of herbicide necessary should be applied at the most effective time(s) of year, and adjacent desirable native species must not be damaged. 6.2.5 Other Maintenance Actions Repair any damage from vandalism and remove trash from the designated mitigation planting areas. Repair and/or replace any damaged signs or fence segments. Repair/replace habitat features as necessary. 6.2.6 Contingency Actions Based on the monitoring data and photographic record, it may be necessary to implement contingency measures to ensure that the Performance Standards are met. The proposed restoration plan can fail under certain circumstances such as unplanned human activity; fire; extreme cold, heat and/or drought; plant loss by disease and/or insect attack; browsing by deer; etc. The monitoring reports will include observations of which plants are lost and the probable cause for the loss. If necessary, plants will be replaced during the dormant season. Care will be taken to correct for the cause of the loss (e.g. providing better maintenance or increased irrigation); replanting species better adapted to actual site conditions; replacing diseased plants with resistant native species; installing herbivory protection devices; etc. Any damages caused by erosion, settling, or other geomorphological processes will be repaired. Chapter 7. Biological and Habitat Assessment This Federal Emergency Management Agency (FEMA) Floodplain Biological and Habitat Assessment has been completed for the May Creek Trail Extension Project per the Floodplain Habitat Assessment and Mitigation Regional Guidance for the Puget Sound basin (FEMA 2013) for compliance with the Endangered Species Act (ESA). The proposed Project includes an approximate 815-foot long, 6-foot wide pedestrian trail in the riparian corridor of May Creek. A portion of the trail is located within a FEMA- mapped Special Flood Hazard Area and will require a floodplain permit and shoreline conditional use permit from the City of Renton. The proposed Project and existing site conditions have been described previously in this report. Mitigation sequencing, the compensatory mitigation approach, monitoring, maintenance, and contingency plans have also been described previously in this report. Shoreline Permit Application Report October 19, 2018 May Creek Trail Extension 15 This biological and habitat assessment (Chapter 7) identifies ESA-listed species in the Project vicinity and assesses the impacts to those species, and to floodplain functions and the primary constituent elements (PCEs) of ESA-listed species. This biological and habitat assessment is based on data derived from WDFW, DNR, City of Renton, NOAA Fisheries West Coast Region, and the Pacific States Marine Fisheries Commission, as well as fieldwork conducted for the proposed Project. Accuracy of this report is dependent upon the data from the above sources and said data is assumed to be accurate and adequate for purposes of evaluating impacts. Best available science has been incorporated into this report using established habitat elements for Puget Sound listed salmonids and incorporating appropriate ESA effects determination protocols for the proposed Project. This report will allow for ESA compliance under Section 7, for which Federal agencies () ensure the actions they take, including those they fund or authorize, do not jeopardize the existence of any listed species. The proposed Project will not result in take of listed species or destruction or disturbance of habitat for listed species, complying with Section 9 of the ESA. 7.1 ESA-Listed Species Present in Project Area Federally listed threatened or endangered species in May Creek include Puget Sound Chinook ESU (Threatened) and Coastal/Puget Sound steelhead (Threatened). Within the project area, no other ESA-listed species are known to occur and suitable habitat for other ESA-listed species is not present. ESA-listed Coastal/Puget Sound Bull Trout (Salvelinus confluentus) (Threatened) is also included in this assessment as it occurs in Lake Washington approximately 0.5-mile downstream of the Project area. No in-water work will occur for the proposed Project; as such, there are no direct effects to the above listed species. Indirect effects to listed species would be limited to modification of surrounding riparian habitat with respect to the proposed Project, as noted below. 7.2 Direct and Indirect Effects to Primary Constituent Elements of Listed Species The PCEs for Puget Sound Chinook and Coastal/Puget Sound steelhead include: · Freshwater spawning sites with water quality and quantity conditions and substrate supporting spawning, incubation and larval development. · Freshwater rearing sites with water quantity and floodplain connectivity to form and maintain physical habitat conditions and support juvenile growth and mobility; water quality and forage supporting juvenile development; and natural cover such as shade, submerged and overhanging large wood, log jams, and beaver dams, aquatic vegetation, large rocks and boulders, side channels, and undercut banks. · Freshwater migration corridors free of obstruction with water quantity and quality conditions and natural cover such as submerged and overhanging large wood, aquatic vegetation, large rocks and boulders, side channels, and undercut banks supporting juvenile and adult mobility and survival. · Estuarine areas free of obstruction with water quality, water quantity, and salinity conditions supporting juvenile and adult physiological transitions between fresh- and saltwater; natural cover such as submerged and overhanging large wood, aquatic vegetation, large rocks and boulders, and side channels; and juvenile and adult forage, including aquatic invertebrates and fishes, supporting growth and maturation. · Nearshore marine areas free of obstruction with water quality and quantity conditions and forage, including aquatic invertebrates and fishes, supporting growth and maturation; and natural cover such as submerged and overhanging large wood, aquatic vegetation, large rocks and boulders, and side channels. Shoreline Permit Application Report October 19, 2018 May Creek Trail Extension 16 · Offshore marine areas with water quality conditions and forage, including aquatic invertebrates and fishes, supporting growth and maturation. The PCEs for bull trout related to the Project includes: · Springs, seeps, groundwater sources, and subsurface water connectivity (hyporehic flows) to contribute to water quality and quantity and provide thermal refugia. · Migratory habitats with minimal physical, biological, or water quality impediments between spawning, rearing, overwintering, and freshwater and marine foraging habitats, including, but not limited to permanent, partial, intermittent or seasonal barriers. · Complex river, stream, lake, reservoir, and marine shoreline aquatic environments, and processes that establish and maintain these aquatic environments, with features such as large wood, side channels, pools, undercut banks and unembedded substrates, to provide a variety of depths, gradients, velocities, and structure. · Water temperatures ranging from 2 to 15 °C (36 to 59 °F), with adequate thermal refugia available for temperatures at the upper end of this range. Specific temperatures within this range will vary depending on bull trout life-history stage and form; geography; elevation; diurnal and seasonal variation; shade, such as that provided by riparian habitat; and local groundwater influence. · Substrates of sufficient amount, size, and composition to ensure success of egg and embryo overwinter survival, fry emergence, and young-of-the-year and juvenile survival. A minimal amount (e.g., less than 12 percent) of fine substrate less than 0.85 mm (0.03 in.) in diameter and minimal embeddedness of these fines in larger substrates are characteristic of these conditions. · A natural hydrograph, including peak, high, low, and base flows within historic and seasonal ranges or, if flows are controlled, they minimize departures from a natural hydrograph. · Sufficient water quality and quantity such that normal reproduction, growth, and survival are not inhibited. · Few or no nonnative predatory (e.g., lake trout, walleye, northern pike, smallmouth bass; inbreeding (e.g., brook trout); or competitive (e.g., brown trout) species present. Effects to PCEs The Project is located 0.5 mile upstream of the mouth of May Creek at Lake Washington. No in-water work is proposed, and nearshore/offshore marine areas and estuaries are not present in or near the Project area. The PCEs for Puget Sound Chinook, Coastal/Puget Sound steelhead, and Coastal/Puget Sound bull trout relative to nearshore/offshore marine areas and estuaries will therefore not be affected by the proposed Project. The Project includes installing the new trail extension at grade partially within the mapped floodplain of May Creek but above the water surface elevations for the 100-year event, which will result in minimal or no change to flood storage or fluvial dynamics in May Creek that could potentially affect in-water habitat for listed fish species. Freshwater spawning sites and water quality and quantity conditions will not be affected as no new pollution generating surfaces are proposed. The existing riparian vegetation provides nutrient inputs to the fluvial aquatic system and foraging opportunities that support growth and maturation during salmonid life stages. The natural cover and shade provided by the existing tree canopy will not be reduced, and the shrub understory will be enhanced by removing invasive plant species and planting native trees and shrubs to supplement the remaining native vegetation. The riparian and upland forest north of May Creek will be extended to the edge of Wetland 7.2R by removing the dense blackberry shrub thicket and restoring a native riparian/upland forest habitat. Shoreline Permit Application Report October 19, 2018 May Creek Trail Extension 17 No indirect effects to PCEs are anticipated as the Project includes extending an existing pedestrian trial. No new land developments are proposed or expected to result from the proposed project. Interrelated and/or interdependent activities will not occur as a result of the proposed Project. 7.3 Direct and Indirect Effects to Other Listed Species Marbled murrelets and other listed terrestrial and marine wildlife species will not be affected by the proposed Project. No in-water noise impacts will occur during the Project that would affect marine mammals. Marbled murrelets are not known to concentrate in Lake Washington for foraging, and no known nests occur within 1 mile of the Project. Marbled murrelets are therefore not expected to be affected by the proposed Project. 7.4 Direct and Indirect Effects to Floodplain Functions This section includes an assessment of direct and indirect effects to floodplain functions as they relate to ESA-listed species in the vicinity of the Project. 1. Water Quality: May Creek is a 303(d)-listed water by the Department of Ecology for temperature, bacteria, and Benthic Index of Biologic Integrity (B-IBI). Water quality post-construction is not expected to change as a result of the trail Project. No discharges of waste material to surface waters in the area will occur, and existing stormwater drainage patterns will not change as stormwater will continue to infiltrate into the soil. No new impervious surfaces will result from this Project, and no changes to water temperature will result. Forest cover in the riparian corridor will increase in the Project area. 2. Water Quantity: No changes to pre-project water patterns will occur as a result of this Project. The trail will have a bark surface and will allow stormwater to infiltrate. The Project will not require any use or of diversion of water from May Creek. 3. Flood Volumes: The proposed trail extension is located within the 100-year FEMA mapped floodplain of May Creek but above the water surface elevations for the 100-year event. The trail will be installed at-grade and will not result in a detectable effect on flood volumes, and thus the 100-year floodplain will not be affected. 4. Flood Velocities: Flood velocities will not be increased by the proposed Project because the trail will be installed at grade following the I-405 widening project. No impacts will occur outside the Project area, and no impacts to flood velocities will occur. 5. Flood Storage Capacity: The Project includes installing the trail at grade, and will not result in the loss of flood storage capacity in the floodplain of May Creek. 6. Spawning Substrate: The Project will occur in the riparian corridor of May Creek, and no in-water work will be performed. The Project area does not impact in-stream spawning habitat for ESA-listed species. 7. Floodplain Refugia: Some large wood exists within May Creek upstream of the Project area. Within the Project site, no large wood will be removed nor will floodplain edge complexity be diminished. Invasive plant species that will be removed will be replaced within the same growing season with native woody plant species. 8. Riparian Vegetation: Forested areas border the May Creek channel within the Project area and provide overhanging vegetative cover. Within the Project area, existing vegetation has minimal engagement with the water surface as May Creek is somewhat confined by steep banks. The vegetation replacement will continue to provide nutrients to the fluvial environment. Overhanging tree canopy effects (shading, nutrient input, etc.) will not be affected, as riparian tree removal for the Project has been avoided. Effects to subcanopy riparian vegetation will be temporary as these functions will be restored within one growing season. Shoreline Permit Application Report October 19, 2018 May Creek Trail Extension 18 7.5 Cumulative Effects to Primary Constituent Elements of Listed Species and Floodplain Functions No negative cumulative impacts to floodplain functions will occur. The proposal is a trail Project that will be installed at-grade, and will improve the existing riparian functions that are currently hindered by infestations of invasive plant species that prevent succession to a climax evergreen forest community. Clearing of herbaceous and shrub species within the shoreline/stream/wetland buffer will be offset by enhanced riparian functions in 1.6 acres of buffer habitat. The proposed Project will not result in foreseeable future federal, state, tribal, local or private actions in the Project action area after the I-405 widening project is complete. 7.6 FEMA Floodplain Habitat Assessment Effect Determination The proposed trail will occur in the riparian corridor of May Creek and will not affect flooding dynamics that could otherwise impact instream habitat. The proposed Project may affect, but is not likely to adversely affect (NLAA) listed salmonid species (Puget Sound Chinook ESU, Puget Sound steelhead), or their habitat because the Project will not adversely affect existing floodplain functions or primary constituent elements of these listed salmonids. Due to the lack of habitat and species presence, the Project will have no effect (NE) on Puget Sound/Coastal bull trout. The 3,660 SF of impacts to the riparian forest understory will be offset by removing invasive plant species and planting native woody vegetation across 1/3 acre in the buffer of May Creek and the adjacent wetlands. 7.7 Project Applicant Contact Information Applicant: City of Renton, ATTN: Angelea Weihs Associate Planner, City of Renton Contact: 1055 S. Grady Way Renton, WA 98057; (425) 430-7312 7.8 Fieldwork Dates and Report Author Qualifications Fieldwork for this report was conducted on June 11, 2018. Jeff Gray, PWS, is a wetland ecologist with nine years of experience performing environmental and ecological investigations, and obtaining required approvals from regulatory agencies for public and private projects. He holds a MS in Natural Resource Management and has performed freshwater and coastal wetland delineations and determinations, developed and implemented mitigation plans, and has prepared permit applications to multiple states and federal agencies. Jeff has obtained Jurisdictional Determinations (JDs) and preliminary JDs to support Section 404/401 permit applications to the US Army Corps of Engineers, and has assisted on endangered and threatened species and habitat field surveys. He has experience selecting, designing, and monitoring wetland mitigation and streambank restoration sites; organizing In-Lieu-Fee payments for mitigation; writing critical areas reports for local jurisdictions; delineating ordinary high water marks (OHWMs); construction monitoring of stream restoration and freshwater/tidal wetland mitigation sites; and providing documentation for Categorical Exclusions, EAs, and EISs in accordance with SEPA and NEPA standards. Stephanie Modjeski is a University of Washington certified wetland scientist and environmental technician. Her experience includes wetland classification and delineation, plant identification, ecological analyses, restoration and field botany, report writing, data collection, ArcGIS software, Shoreline Permit Application Report October 19, 2018 May Creek Trail Extension 19 environmental permit application preparation, and environmental law. She prepares SEPA and NEPA documentation, critical areas reports, and JARPAs and HPA applications. She has experience conducting field botany plant identification, aquatic invertebrate collection and identification, and wetland and buffer monitoring. Kevin O’Brien, PhD, is a wildlife biologist and ecologist with 25 years of experience working in the fields of ecology, zoology, and wildlife biology. Kevin holds a PHD in Zoology and BA in Biology. Kevin’s experience includes conducting stream habitat surveys and wetland delineations; assessing vegetation and wildlife habitat; assessing anadromous fish habitat and fish passage; collecting and performing statistical analyses on data for insects, birds, and mammals; studying habitat fragmentation; and conducting population and community-level ecological studies and experiments. One of Kevin’s primary roles is to conduct impact and risk analyses for threatened and endangered species and designated critical habitat, including analyses of direct and indirect impacts, interrelated and interdependent effects, and cumulative impacts analyses. He regularly leads stream habitat assessment and analysis efforts to provide information for baseline conditions in individual stream systems and at the broader basin and watershed scale. Kevin has extensive experience preparing Biological Assessments/Evaluations (BAs/BEs) to meet the requirements of the Endangered Species Act (ESA) and is certified as a senior BA preparer through WSDOT’s and ODOT’s qualification processes. He regularly prepares Environmental Impact Statements (EISs)/ Environmental Assessment (EA) and NEPA Categorical Exclusions, as well as technical support documents and discipline reports to meet SEPA/ NEPA guidelines, and is an expert at providing the necessary environmental documentation for projects involving in-stream restoration design and work in other environmentally critical areas. Shoreline Permit Application Report September 7, 2018 May Creek Trail Extension 20 Chapter 8. References City of Renton. 2018. Renton Municipal Code. Available online at https://www.codepublishing.com/WA/Renton/, accessed on August 13, 2018. Hruby, T. 2014. Washington State Wetland Rating System for Western Washington: 2014 update. Washington State Department of Ecology Publication # 14-06-029. Olympia, Washington. NRCS. 2018. Web Soil Survey. United States Department of Agriculture. Available online at http://websoilsurvey.nrcs.usda.gov/., accessed July 23, 2018. Otak, Inc. 2018. May Creek Trail Extension Critical Areas Review. Prepared for the City of Renton. Washington Department of Natural Resources (WDNR). 2018. Forest Practices Application Mapping Tool. Available online at https://fortress.wa.gov/dnr/protectiongis/fpamt/default.aspx, accessed on July 23, 2018. Washington State Department of Ecology, U.S. Army Corps of Engineers Seattle District, and U.S. Environmental Protection Agency Region 10. 2006a. Wetland Mitigation in Washington State - Part 1: Agency Policies and Guidelines (Version 1). Washington State Department of Ecology Publication #06-06-011a, Olympia, WA. Washington State Department of Ecology, U.S. Army Corps of Engineers Seattle District, and U.S. Environmental Protection Agency Region 10. 2006b. Wetland Mitigation in Washington State - Part 2: Developing Mitigation Plans (Version 1). Washington State Department of Ecology Publication #06- 06-011b, Olympia, WA. Washington State Department of Transportation (WSDOT). 2018. Wetland and Stream Assessment Report, I-405, Renton to Bellevue Corridor- Milepost 4.0 – 13.7. Appendix A — Critical Areas Memo and Photo-log Technical Memorandum To: Angelea Weihs, City of Renton From: Jeff Gray, MS, PWS Stephanie Modjeski, Wetland Biologist Copies: Lori McFarland, Otak Date: August 20, 2018 Subject: Critical Areas Review for the May Creek Trail Extension Project Project No.: 032978 Introduction This memorandum presents the findings of the critical areas survey for the May Creek Trail Extension Project (project) in the City of Renton (City) in King County, Washington. Compliance with the Shoreline Master Program Regulations at Renton Municipal Code (RMC) Chapter 4-3-090 will be required for the project, including no net loss of ecological functions and consistency with applicable critical areas regulations at RMC Chapter 4-3-050. Critical areas covered in this review include flood hazard areas, habitat conservation areas, streams and lakes, and wetlands. The proposed project includes a pedestrian trail extension from Jones Avenue NE to the exis ting May Creek Trail west of Interstate 405 (I-405). The trail extension will be routed underneath I-405 along the north side of May Creek. The portion of the proposed trail within Washington State Department of Transportation (WSDOT) right of way (ROW ) has already been authorized under LUA17-00808 SM, CAR, SMV. This critical areas review memorandum is provided to support permitting for the trail sections outside of the WSDOT ROW. The entire project will be constructed by WSDOT as a mitigation component of the I-405 widening. The portion of the trail outside of the WSDOT ROW will be 6-feet wide and generally follow the existing ground elevations and alignment of May Creek. In addition, the May Creek riparian buffer will be cleared of invasive plants and restored with native woody vegetation to improve riparian habitat and ecological functions in the project area. Wetland and stream delineations were completed in the project area by WSDOT in May 2016 for the I-405 widening project and documented in the Wetland and Stream Assessment Report, I-405, Renton to Bellevue Corridor Milepost 4.0-13.7 (2018). The scope of this critical areas review includes verifying critical area boundaries identified in that report for the project area. Methods Otak biologists conducted a site visit on June 11, 2018 to verify previous delineations and characterizations of wetlands and streams by WSDOT, and assess potential impacts associated with clearing and grading within critical areas. The project is located in Section 32, Township 24, Range 05 East of the Public Land Survey System. Page 2 May Creek Trail Extension Critical Areas Review August 20, 2018 Wetland boundaries were determined using methodology derived from the Regional Supplement to the Corps of Engineers Wetland Delineation Manual: Western Mountains, Valleys, and Coast Region (USACE, 2010) and the Corps of Engineers Wetland Delineation Manual (Environmental Laboratory 1987). Vegetation communities, soil profiles and site hydrology were assessed to identify and confirm wetland boundaries. Wetland determination data forms were completed to document wetland presence/absence determinations and are included with this memorandum. The boundaries of streams within the project area were determined using methodology from Determining the Ordinary High Water Mark for Shoreline Management Act Compliance in Washington State (Ecology 2016). Identification of ordinary high water mark (OHWM) was based on field indicators and stream physical characteristics such as: line of vegetation, erosional or depositional features, changes in sediment and vegetation characteristics, wracking, erosion/scour, and silt deposits. Background Information Review Otak completed a review of existing environmental information and data associated with the proposed trail alignment, including available mapping from the City, King County, Washington Department of Fish and Wildlife (WDFW), Washington State Department of Natural Resources (DNR), WSDOT, United States Fish and Wildlife Service (USFWS), and the Natural Resource Conservation Service (NRCS). Background information maps are included with this memorandum. The following WSDOT materials were reviewed: ▪Wetland and Stream Assessment Report, I-405, Renton to Bellevue Corridor Milepost 4.0-13.7, prepared by WSDOT, dated January 2018. ▪JARPA figures for the I-403, Renton to Bellevue Project, prepared by WSDOT, dated November 8, 2017 The following online resources were also reviewed for additional background information, accessed on June 8, 2017: ▪City of Renton (COR) Map Viewer (http://rp.rentonwa.gov/Html5Public/Index.html?viewer=CORMaps) ▪King County iMap (https://gismaps.kingcounty.gov/iMap/) ▪WDFW Priority Habitats and Species (PHS) on the Web (http://wdfw.wa.gov/mapping/phs/) ▪WDFW SalmonScape (http://apps.wdfw.wa.gov/salmonscape/map.html) ▪DNR Forest Practices Application Mapping Tool (https://fpamt.dnr.wa.gov/default.aspx) ▪USFWS National Wetlands Inventory (NWI) (https://www.fws.gov/wetlands/data/mapper.HTML) ▪United States Department of Agriculture- National Resource Conservation Service (USDA-NRCS) Web Soil Survey (https://websoilsurvey.sc.egov.usda.gov/App/HomePage.htm ) ▪FEMA Flood Map Service Center: https://msc.fema.gov/portal/home Norma sandy loam is the only soil unit mapped within the project area by NRCS. Norma sandy loam that occurs on floodplains is listed as a hydric soil. However, no wetlands are mapped within the project area per King County iMap, WDFW PHS on the Web, or the NWI m apper. WSDOT maps one forested wetland (identified as Wetland 7.2R) north of the project site within shoreline jurisdiction. Wetland 7.2R is rated as Category III per the Washington State Wetland Rating System for Western Washington – 2014 Update (Hruby 2014) and is assigned a 75-foot or 125-foot wide buffer variably within the report. The City of Renton COR Map Viewer shows a wetland in the same location of Wetland 7.2R that extends beyond May Creek to the south. May Creek is listed as a Type S (shoreline) watercourse, and the project area is zoned as Urban Conservancy per the City’s Shoreline Management Program. Type S watercourses have a standard buffer width of 200 feet per RMC 4-3-090B (Regulated Shorelines). ESA-listed species that utilize May Creek include Puget Sound Page 3 May Creek Trail Extension Critical Areas Review August 20, 2018 Chinook salmon (Oncorhynchus tshawytscha) Evolutionary Significant Unit (ESU) and Puget Sound/Coastal steelhead (Oncorhynchus mykiss) Distinct Population Segment (DPS), but May Creek has not been designated as critical habitat for either species. Per WDFW’s SalmonScape, other salmonid species documented within May Creek include Sockeye and Coho salmon. Resident cutthroat trout (Oncorhynchus clarki) is also known to occur in May Creek. A Special Flood Hazard Area (100 year flood, Zone AE) is mapped on the north side of May Creek east of I-405 and is also shown on Flood Insurance Rate Map Panel 664 of 1700 (Map Number 53033C0664G). Sections of the trail appear to be located within the mapped floodplain. Results of the Field Survey An informal dirt trail currently connects the existing May Creek Trail to Jones Avenue NE. The informal trail follows the north side of May Creek beneath I-405 and extends through a thicket of Himalayan blackberry (Rubus armeniacus) and reed canarygrass (Phalaris arundinacea) before connecting with Jones Avenue NE. No wetlands or terrestrial habitat conservation areas were identified within the project area. The boundary of Wetland 7.2R mapped by WSDOT is consistent with field observations. The wetland boundary was staked in the field by Otak surveyors and verified by Otak biologists. T he southernmost boundary of Wetland 7.2R is located at the northern edge of the blackberry thicket generally along the tree line. Wetland 7.2R does not extend onto the project area as indicated on the COR Map Viewer. Two data points (DP1 and DP2) were taken during the field survey to document upland conditions in the project area north of May Creek . DP1 is located within the non- forested Himalayan blackberry thicket, and DP2 is located at the top of bank of May Creek within the forested riparian area. Both data points are shown on City of Renton Critical Areas Map included with this memorandum. Wetland 7.2R is located within the 200-foot shoreline boundary of May Creek. The Category III rating of W etland 7.2R was confirmed along with the habitat score of 5 (20-28 points using the 2004 wetland rating system). Per RMC 4-3-090D.2.d.iv a Category III wetland with moderate wildlife function points (20-28 points) within shoreline jurisdiction has a buffer width of 125 feet. The OHWM of May Creek was delineated by WSDOT and verified in the field by Otak biologists. Several of the OHWM flags hung by WSDOT biologists in 2016 were still in place. The delineated OHWM was consistent with field observations and previous mapping by WSDOT . May Creek is a Type S watercourse with a 200-foot wide buffer. The riparian buffer of May Creek and the buffer off the southern edge of Wetland 7.2R is dominated by invasive plant species. A large Himalayan blackberry upland field is located immediately east of the I-405 underpass. The banks of May Creek are forested with a dense understory of Himalayan blackberry, knotweed (Polygonum sp.), bracken fern (Pteridium aquilinum) and reed canarygrass. Tree species within the project area include red alder (Alnus rubra), big leaf maple (Acer macrophyllum), black cottonwood (Populus balsamifera spp. trichocarpa), and non-native black locust (Robinia pseudoacacia). In addition, an unnamed tributary to May Creek was identified outside of the project area flowing west along the southern edge of Parcel #3345700097 towards Jones Avenue NE. The tributary flows through a culvert and discharges to May Creek south of the project area. The tr ibutary is shown on King County’s iMap and the COR Map Viewer. Roadside ditches along the east side of the Jones Avenue NE had flowing water at the time of the field survey that discharged to the unnamed tributary. These features were determined to be outside of the project area. Page 4 May Creek Trail Extension Critical Areas Review August 20, 2018 Shoreline Management Plan and Critical Areas Regulations Review The proposed trail extension project is located within shorelands regulated under the City’s Shoreline Master Program. The project area is zoned as Urban Conservanc y. Public trails over land are a permittable activity within Urban Conservancy overlay district, provided that the use does not degrade the ecological functions or natural character of the shoreline area (Table 4-3-090.E.1-Shoreline Use Table). Allowed activities in buffers of Category III wetlands within shoreline jurisdiction include recreational or educational activities (e.g., trails), if the following criteria are met [RMC 4-3-090D.2.d.ix(f)]: (1) Trails shall not exceed four feet (4') in width and s hall be surfaced with gravel or pervious material, including boardwalks; (2) The trail or facility is located in the outer fifty percent (50%) of the buffer area unless a location closer to the wetland edge or within the wetland is required for interpretive purposes; (3) The trail or facility is constructed and maintained in a manner that minimizes disturbance of the wetland or buffer. Trails or facilities within wetlands shall be placed on an elevated structure as an alternative to fill; (4) Wetland mitigation in accordance with subsection D2dx of this Section. Use regulations for trails within the Urban Conservancy overlay district are described at RMC 4 -3-090E.10(d): i. Trails that provide public access on or near the water shall be located, designed, and maintained in a manner that protects the existing environment and shoreline ecological functions. Preservation or improvement of the natural amenities shall be a basic consideration in the design of shoreline trails. ii. The location and design of trails shall create the minimum impact on adjacent property owners including privacy and noise. iii. Over-water structures may be provided for trails in cases where: (a) Key trail links for local or regional trails must cross streams, wetlands, or other water bodies. (b) For interpretive facilities. (c) To protect sensitive riparian and wetland areas from the adverse impacts of at grade trails, including soil compaction, erosion potential and impedance of surface and groundwater movement. iv.Trail width and surface materials shall be appropriate for the context with narrow soft surface trails in areas of high ecological sensitivity where the physical impacts of the trail and the number of users should be minimized with wider hard-surfaced trails with higher use located in less ecologically sensitive areas. Shoreline development shall result in no net loss of ecological functions and comply with Critical Areas Regulations at RMC 4-3-050 unless otherwise specified. An impacts assessment and evaluation of mitigation sequencing is required. Per RMC 4-3-090D.2.d.x(e), compensation for wetland buffer impacts shall occur at a minimum 1:1 ratio. Compensatory mitigation for buffer impacts shall include enhancement of degraded buffers by planting native species, removing structures and impervious surfaces within buffers, and other measures. A Vegetation Management Plan is also required to maintain effective buffer conditions and functions (RMC 4 -3- 090D.2.d.xii). Per RMC 4-3-090F.1 (Vegetation Conservation), a vegetation conservation buffer width of 100 feet measured from the OHWM of May Creek. Vegetation in the conservation buffer areas that are largely undistributed native vegetation shall be retained except where the buffer is to be enhanced or where alteration is allowed. Removal of noxious weeds and invasive species is allowed within the vegetation conservation buffer area. Page 5 May Creek Trail Extension Critical Areas Review August 20, 2018 The proposed project includes mitigating for impacts to the shoreline environment by avoiding direct impacts to wetlands and watercourses, minimizing impacts to wetland and stream buffers, and compensating for unavoidable impacts through buffer enhancement. The project includes clearing invasive species from the vegetation conservation and wetland buffers on site. The current functions of the stream buffer are impeded by dense Himalayan blackberry growth that prevents the establishment of native woody species and the natural succession toward a multi-strata forested plant community. Clearing invasive plants from the regulated buffers and shorelands and installing native trees and shrubs will increase the overall ecological functions in the shoreline environment on site. Encl. Background Information Maps for the Project Area, Site Photographs, Figure 1 (City of Renton Critical Areas Map), Existing Buffer Exhibit References City of Renton COR Maps. 2018. Available at http://rp.rentonwa.gov/Html5Public/Index.html?viewer=CORMaps Accessed June 8, 2018. Cowardin, L.M., V. Carter, F. Golet, and E.T. LaRoe. 1979. Classification of wetlands and deepwater habitats of the United States. FWS/OBS-70/31. 131 pp. Washington, D.C: U.S. Fish & Wildlife Service, Office of Biological Services. King County iMap. 2018. Available at http://gismaps.kingcounty.gov/iMap/ . Accessed June 8, 2018. U.S. Army Corps of Engineers (USACE). 1987. Corps of Engineers Wetland Delineation Manual. Technical Report. Y-87-1. Vicksburg, Mississippi: U.S. Army Corps of Engineers Environmental Laboratory. USACE. 2010. Regional Supplement to the Corps of Engineers Wetland Delineation Manual: Western Mountains, Valleys, and Coast Region, Version 2.0, ed. J.S. Wakeley, R.W. Lichvar, and C.V. Noble. ERDC/EL TR-10-3. Vicksburg, Mississippi: U.S. Army Engineer Research and Development Center. U.S. Department of Agriculture- National Resource Conservation Service (USDA-NRCS) Web Soil Survey. 2018. Available at https://websoilsurvey.sc.egov.usda.gov/App/HomePage.htm . Accessed June 8, 2018. U.S. Fish and Wildlife National Wetlands Inventory. 2018. Available at https://www.fws.gov/wetlands/data/mapper.HTML . Accessed June 8, 2018. Washington Department of Natural Resources (WDNR). 2018. Forest Practices Application Mapping Tool. Available online at https://fortress.wa.gov/dnr/protectiongis/fpamt/default.aspx, accessed on June 8, 2018. Washington Department of Ecology (Ecology). 2010. Determining the Ordinary High Water Mark For Shoreline Management Act Compliance in Washington State– Revised October 2016. Ecology publication #16-06-029. Olympia, WA. Page 6 May Creek Trail Extension Critical Areas Review August 20, 2018 Washington Department of Fish and Wildlife Priority Habitats and Species (PHS) on the Web. 2018. Available at http://wdfw.wa.gov/mapping/phs/. Accessed June 8, 2018. Washington State Department of Transportation. 2018. Wetland and Stream Assessment Report, I-405, Renton to Bellevue Corridor, Milepost 4.0-13.7. Background Information Maps for the Project Area Map 1. City of Renton’s COR Map Viewer showing critical areas (wetlands and streams) in the approximate study area (identified by the red polygon) for the project. Source: http://rp.rentonwa.gov/Html5Public/Index.html?viewer=CORMaps Page 7 May Creek Trail Extension Critical Areas Review August 20, 2018 Map 2. NWI Map. Freshwater riverine habitat (May Creek) is shown flowing north underneath I-405. No NWI-mapped vegetated wetland habitats exist within the project vicinity. Source: https://www.fws.gov/wetlands/data/mapper.HTML Page 8 May Creek Trail Extension Critical Areas Review August 20, 2018 Map 3. WDFW Priority Habitats and Species Map. May Creek is shown flowing into Lake Washington. No wetlands or other priority habitats or species are mapped within the project vicinity. Project location is represented by the red star. Source: http://apps.wdfw.wa.gov/phsontheweb/ Page 9 May Creek Trail Extension Critical Areas Review August 20, 2018 Page 10 May Creek Trail Extension Critical Areas Review August 20, 2018 Site Photographs Photo 1. View west from near Jones Avenue NE of the informal trail leading through the blackberry thicket east of I-405. Photo 2. View of the vegetation community at Data Point 1 (DP1). Reed canarygrass and blackberry dominate the understory. Page 11 May Creek Trail Extension Critical Areas Review August 20, 2018 Photo 3. View of the vegetation community at DP2, including a dense understory dominated by blackberry. Photo 4. View west of riparian vegetation along May Creek east of I-405, including non-native species knotweed (Polygonum sp.), Himalayan blackberry, and reed canarygrass. Page 12 May Creek Trail Extension Critical Areas Review August 20, 2018 Photo 5. View north along Jones Avenue NE near the proposed trail terminus. Appendix B — WSDOT Wetland and Stream Assessment Report Available upon request –the size of the documentation does not allow for inclusion in this Appendix Appendix C — Neighborhood Detail Map