Loading...
HomeMy WebLinkAboutAttachment_C_RS_Lake_Study_260211_v14163 Williams Shoreline Repair Lake Study/No Net Loss Determination Prepared for 4163 LLC 4163 Williams Avenue N Renton, WA 98056 Prepared by Northwest Environmental Consulting, LLC 3639 Palatine Avenue North Seattle, WA 98103 206-234-2520 December 2025 4163 Williams Shoreline Repair Lake Study 1 Project Purpose The project purpose is to repair shoreline access at one residence in the Barbee Mill housing community. The existing log that served as a wave break for erosion protection has deteriorated over time. A new log will be placed on the beach, new concrete steps will be placed from the beach to the existing stairs and walkway, and hand rails will be installed for the new and existing steps. Location The subject property is located at 4163 Williams Avenue N (King County parcel number 0518500340) in the City of Renton, Washington (Sheet 1). The parcel is on the waterfront of Lake Washington. Project Description The proposed work is to place a new log on the beach, secured by steel chains and Manta Ray soil anchors, and install concrete steps from the beach to the existing stairs and walkway, with hand rails for the new and existing stairs. Project drawings are included in Appendix A – Project Drawings. Approach Northwest Environmental Consulting LLC (NWEC) biologist Brad Thiele conducted a site visit in November 2025 to evaluate conditions on site and adjacent to the site. NWEC also consulted the following sources for information on potential critical fish and wildlife habitat along this shoreline: • City of Renton COR Maps online database (https://rp.rentonwa.gov/HTML5Public/Index.HTML?viewer=CORMaps) • Washington State DNR Natural Heritage Features database (https://www.dnr.wa.gov/publications/amp_nh_trs.pdf?znn6z) • Washington Department of Fish and Wildlife (WDFW): Priority Habitats and Species online database (http://apps.wdfw.wa.gov/phsontheweb/) • WDFW SalmonScape online database of fish distribution and ESA listing units (https://apps.wdfw.wa.gov/salmonscape/) Site Description The subject property is a suburban shoreline tract in Renton. It has shoreline on its eastern boundary with a housing development and beach club landward, a shoreline residential neighborhood to the south, and vacant land belonging to Quendall Terminals to the north. 4163 Williams Shoreline Repair Lake Study 2 The residential development is fully built out, with multi-unit homes, an access roadway, and a community building. Some mowed grass and ornamental landscaping surround the homes. The yard is landscaped with a planting bed with native shrubs that include red osier dogwood, snowberry, Oregon grape, and kinnikinnick that abuts a small rockery above the beach. A degraded set of wood stairs leads down to the beach from the yard. The shoreline is a gravel beach with several logs along and above the OHWM elevation of the lake. The substrate of the lake is sand, gravel, and cobble. May Creek enters Lake Washington on the southern edge of the Barbee Mill development. Residential docks exist south of the development; there are no docks within the Barbee Mill development. Lake and Stream Classifications As a Shoreline of Statewide Significance (RMC 4-3-090B1) Lake Washington is defined as a Shoreline of the State (RMC 4-11-190S). The Shoreline is designated as “Urban Conservancy” (City of Renton 2025). May Creek enters the lake on the southern edge of the development. May Creek is documented to support spawning of fall Chinook salmon, coho, winter steelhead, and sockeye salmon (SalmonScape 2025). Ordinary High Water Mark The Ordinary High Water Mark (OHWM) for Lake Washington is the line of mean high water (RMC 4-11-150 Definitions O). The Lake Washington water depth is controlled by the Army Corps of Engineers at the Hiram M. Chittenden Locks and is at 21.8 feet above sea level (Corps of Engineers Datum). The OHWM at the project site is shown in Appendix A – Project Drawings. Vegetative Cover of the Site There are no wetlands or floodplains mapped as occurring in the study area. Floodplains occur on both sides of May Creek further upstream. There are no DNR Natural Heritage Features listed in the study area (Figure 2). The site is maintained as a multi-family housing development with some landscaping. Ecological Functions of Lake Washington at Site The site lacks native plantings that would provide habitat functions along the shoreline. The shoreline is gravel beachfront. There is a vacant parcel north of the site belonging to Quendall Terminals with shoreline vegetation. The 303(d) list shows the lake bed immediately north of the site as Category 5 (polluted) for sediment bioassay, and the water in the same area as Category 5 for HPAH (High Molecular Weight Polyaromatic Hydrocarbons), LPAH (Low Molecular Weight Polyaromatic Hydrocarbons), and phenol; Category 2 (of concern) for PCBs (Polychlorinated biphenyls). May Creek is Category 5 for temperature, fecal coliform, E. coli, and sediment bioassay; and Category 2 for dissolved oxygen and mercury. The shorelines of Lake Washington and May Creek are designated Riparian Management Areas by WDFW (Figure 3). 4163 Williams Shoreline Repair Lake Study 3 Species Use Birds Birds observed near the site include raptors, herons, eagles, waterfowl, and songbirds. Bald eagles, protected by the Bald and Golden Eagles Protection Act and the Migratory Bird Treaty Act, are protected as a “sensitive species” within the state of Washington (WAC 232-12-011). Eagles were not observed in the area during the site study and no nest or adequate nesting trees were visible along the shoreline. Bald eagles and other raptors are common on along the shoreline of Lake Washington. Bird Island, less than a half mile to the east, supports many native birds. Mammals No wild mammals were observed during the site visit, but Lake Washington is known to have river otters, beavers, nutrias, and muskrats. Deer and coyotes are known to be present in the vicinity. Fish WDFW’s PHS mapping and SalmonScape mapping tools show the following salmonid species using Lake Washington for migration and/or rearing: residential coastal cutthroat (Oncorhynchus clarki), winter steelhead (O. mykiss), Dolly Varden/bull trout (Salvelinus malma), sockeye salmon (O. nerka), fall Chinook (O. tshawytscha), coho salmon (O. kisutch), and kokanee (O. nerka). The Salmonscape database maps the site as critical habitat to the Evolutionarily Significant Unit (ESU) of Threatened Chinook and steelhead (Figure 3). Fall Chinook salmon and winter steelhead are mapped as rearing in the first mile of May Creek, and spawning upstream. Coho salmon are mapped as rearing in the first few hundred feet of May Creek, and spawning upriver. The nearest salmon stream is May Creek, which enters the lake at the southern edge of the Barbee Mill development, a few hundred feet from the project area. The project site is accessible to any fish migrating or rearing in the lake, and Lake Washington is designated as critical habitat for Endangered Fall Chinook salmon. Measures to Protect Trees and Vegetation No trees will be disturbed during construction as all work will occur on the beach. No vegetation will be removed. Project Impacts and Conservation Measures Direct Impacts: Sediments: Sediment disturbance will be minimal from installing Manta Ray anchors to secure the log in place. Contaminated sediments north of the site will not be disturbed. Impacts to sediments should be minimal from work on the beach. Forms will be used for the concrete steps, and uncured concrete will not be permitted to contact the water. The project actions are not expected to exceed State Water Quality Standards. 4163 Williams Shoreline Repair Lake Study 4 Lakebed: The proposed project will not affect the lake bed. All work will be done on the beach. Noise: Noise will not be significantly higher than background levels. No impact equipment will be used. Noise will have negligible effects on fish and wildlife in the area. Work will be completed during the in-water work window when juvenile fish are not expected to be present. Potential spills: Short-term risks include the potential for spillage of wet concrete while casting the steps. Forms will be used, which minimize the likelihood of wet concrete escaping the immediate area. The chance of impact to the aquatic environment is reduced because a crew trained in using spill containment measures will be on site and employ these measures should a spill occur. Indirect Impacts: Shoreline Armoring: The project contributes to shoreline armoring in Lake Washington; however, this technique using natural materials is less invasive, and protects the beach gravel already in place. Stormwater: The new concrete steps will increase runoff from impervious surfaces on site. The steps are for foot traffic only and will not increase stormwater associated pollutants. Lake Washington is exempt from runoff quantities and the new impervious surface is minimal. Other Conservation measures: Work window: The work will be completed during the prescribed in-water work window for this area of Lake Washington (July 16 to December 31). Operating within this time frame helps protect Chinook salmon, steelhead, bull trout and other salmonid fish species. Best Management Practices: Applicable BMPs will be used to prevent uncured concrete from contacting the water. Hazardous material containment materials such as spill absorbent pads and trained personnel will be required onsite during any phase of construction where machinery is in operation near surface waters. Mitigation Strategy Avoidance and Minimization Impacts to Lake Washington cannot be avoided. The project has been designed to reduce impacts by using BMPs to reduce potential impacts from construction. The repairs minimize impacts by using natural materials for erosion protection. The maintenance repairs are the minimum necessary to complete the work. All work is landward of the Ordinary High Water Mark. Shoreline Function and Values Project activities will not affect shoreline functions. The proposal is for a maintenance of existing erosion protection and to rebuild degraded wood steps. 4163 Williams Shoreline Repair Lake Study 5 Conclusion Juvenile Chinook salmon, and other salmonids, rear and migrate along the Lake Washington shoreline. There will be temporary impacts from disturbed sediments during installation of the Manta Ray anchors to secure the log on the beach. The steps will not introduce stormwater pollutants and are built over an existing foot path and wood stairs. The project will minimize construction effects on the environment by following the prescribed in water work window and use applicable BMPs to prevent construction spills and debris from escaping the area. Anchoring large woody material (LWM) in the nearshore environment will provide habitat complexity and provide complex substrates for aquatic insects and invertebrates providing additional forage opportunities for fish. The LWM may also provide cover for juvenile fish improving rearing habitat during high water. This project will use Best Management Practices to reduce project impacts. The conservation measures are designed to preserve ecological functions or prevent further degradation of habitat and will result in No Net Loss of ecological functions at the site. Document Preparers Brad Thiele Biologist 31 years of experience NWEC Kristin Noreen Permit Specialist 26 years of experience NWEC The conclusions and findings in this report are based on field observations and measurements and represent our best professional judgment and to some extent rely on other professional service firms and available site information. Within the limitations of project scope, budget, and seasonal variations, we believe the information provided herein is accurate and true to the best of our knowledge. Northwest Environmental Consulting does not warrant any assumptions or conclusions not expressly made in this repo rt, or based on information or analyses other than what is included herein. 4163 Williams Shoreline Repair Lake Study 6 REFERENCES City of Renton. 2025. COR Maps. Accessed August 2025 at https://maps.rentonwa.gov/Html5viewer/Index.html?viewer=CORMaps. City of Renton Municipal Code (RMC). 2021. RMC Section 4-8-120. Code Publishing. Accessed August 2025 at https://www.codepublishing.com/WA/Renton/#!/Renton04/Renton0408/Renton0408120. html Washington Department of Fish and Wildlife (WDFW). 2025. Priority Habitats and Species. Online database. Accessed November 2025 at http://apps.wdfw.wa.gov/phsontheweb/ WDFW. 2021. SalmonScape. Online database. Accessed November 2025 at http://apps.wdfw.wa.gov/salmonscape/ Washington State Department of Natural Resources. 2025. Sections that Contain Natural Heritage Features. Accessed November 2025 at https://www.dnr.wa.gov/publications/amp_nh_trs.pdf?znn6z Appendix A: Project Drawings PROJECT SITE: LAT: 47.529811° N LON: -122.205113° W NW 1/4 S:32 T:24N R:5E PROJECT INFORMATION VICINITY MAP4 1 6 3 W I L L I A M S S H O R E L I N E R E P A I R OWNER: 4163 LLC SITE ADDRESS: 4163 WILLIAMS AVE N RENTON, WA 98056 PARCEL NUMBER: 051850-0330 BODY OF WATER: LAKE WASHINGTON LEGAL DESCRIPTION: BARBEE MILL TGW UND INT IN TRS A,B,C,D,E,F,G, H,I,J,L,M,N,O & P PLAT LOT: 33 PROJECT DESCRIPTION: INSTALL A NEW LOG LANDWARD OF THE EXISTING ORDINARY HIGH WATER MARK. INSTALL NEW CONCRETE STEPS LANDWARD OF THE ORDINARY HIGH WATER MARK. INSTALL THREE HANDRAILS ON EXISTING STEPS TO THE SHORELINE. A1.0 REVISIONS: DATE: 8/26/2025 41 6 3 W I L L I A M S S H O R E L I N E R E P A I R 41 6 3 W I L L I A M S A V E N RE N T O N , W A 9 8 0 5 6 PROJECT INFO SITE PLAN SECTIONS Architecture & Design 7413 Greenwood Ave N Seattle, WA 98103 OHW 21.85' LOG SECTION DETAIL SCALE 1/2" = 1'-0" EXISTING LOG (APPROX 2' IN DIAMETER) INSTALL MANTA RAY SOIL ANCHOR INSTALL NEW LOG (APPROX 2' IN DIAMETER) INSTALL STEEL CHAIN ADD 9" CRUSHED ROCK LANDWARD OF LOG TO REPLACE WASHED AWAY ROCKS 0'4'2' 4163 LLC 4163 WILLIAMS AVE N PAMELA MANDEL 4157 WILLIAMS AVE N WENDY & RAYMOND MYERS 4169 WILLIAMS AVE N 154.49' 157.27' 37 . 0 0 ' 3 7 . 0 6 ' EXISTING LOGS (NO WORK) OHWM 21.85' INSTALL NEW LOG LANDWARD OF OHWM INSTALL NEW CONCRETE STEPS LANDWARD OF OHWM EXISTING CONCRETE PATHWAY (NO WORK) S I T E P L A N SCALE 1" = 10'-0" 8'-0" 4' - 0 " 33 ' - 0 " INSTALL HAND RAILS ON EXISTING STEPS LAKE WASHINGTON 0'20'10' OHW 21.85' INSTALL NEW CONCRETE STAIRS EXISTING CONCRETE PATHWAY STAIR SECTION DETAIL SCALE 1/2" = 1'-0" 0'4'2' 8'-0" 1'-4" TYP. 5" T Y P . 2' - 9 " INSTALL HANDRAIL 2' - 1 1 " King T24R05E T23R05E 33 28 456 29 30 32 31 WNHP Rare Plant and Ecosystem Locations Esri, NASA, NGA, USGS, FEMA, Sources: Esri, TomTom, Garmin, FAO, NOAA, USGS, © OpenStreetMap contributors, and the GIS User Community Public Land Survey Sections Public Land Survey Townships State Boundary County Boundaries World_Hillshade 11/30/2025, 3:44:15 PM 0 0.2 0.40.1 mi 0 0.35 0.70.17 km 1:21,029 WNHP Plant & Ecosystem Map Viewer KNOWN PLANT AND ECOSYSTEM LOCATIONS REFLECT KNOWN OCCURRENCE LOCATIONS BUT MAY NOT REFLECT ALL OCCURRENCES OF RARE PLANTS OR ECOSYSTEMS. DISCLAIMER. This report includes information that the Washington Department of Fish and Wildlife (WDFW) maintains in a central computer database. It is not an attempt to provide you with an official agency response as to the impacts of your project on fish and wildlife. This information only documents the location of fish and wildlife resources to the best of our knowledge. It is not a complete inventory and it is important to note that fish and wildlife resources may occur in areas not currently known to WDFW biologists, or in areas for which comprehensive surveys have not been conducted. Site specific surveys are frequently necesssary to rule out the presence of priority resources. Locations of fish and wildlife resources are subject to variation caused by disturbance, changes in season and weather, and other factors. WDFW does not recommend using reports more than six months old. Priority Habitats and Species on the Web Report Date: 12/18/2025 The Priority Habitats and Species (PHS) datasets do not contain information for your project area. This does not mean that species and habitats do not occur in your project area. PHS data, points, lines and polygons are mapped only when occurrences of these species or habitats have been observed in the field. Unfortunately, we have not been able to comprehensively survey all sections in the state and therefore, it is important to note that priority species and habitats may occur in areas not currently known to the Department. 12/18/25, 2:07 PM PHS Report about:blank 1/1 Appendix B: Site Photographs