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HomeMy WebLinkAboutRS_Stream Study_240614_v1.pdf ATTACHM ENT 20: STANDARD STREAM OR LAKE STUDY 425-869-2670 ■ 15325 SE 30th Place, Suite 300 ■ Bellevue, Washington 98007 ■ www.dowl.com Stream Classification The Windsock Apron is adjacent to (within 200 feet of) the Cedar River and its floodplain area. The Cedar River is classified as a Shoreline of the State by Renton Municipal Code (RMC) 4-3- 090. This project is entirely outside of and will not interact with the floodplain area. Vegetative Cover The Windsock Apron project area is entirely covered with pavement. The surrounding areas to the south and west are mowed grasses. There is a narrow strip of grass to the east and then a fence. Outside of the fence, there is a narrow strip of riparian vegetation including trees and shrubs. The proposal will not impact any vegetation in the vicinity of the Cedar River. Ecological Functions Overall, the reach of the Cedar River that flows through Renton has limited ecological functions due to urban development. Access to the floodplain is limited and the channel has been straightened. Trees and shrubs along the bank provide shading and nutrient input. However, the riparian corridor is limited due to adjacent development. The Cedar River provides instream habitat for salmonid species and prey species including sculpin and lamprey. The Cedar River serves as an important migration corridor, as it outlets to Lake Washington which outlets to the Puget Sound. The proposal will not result in any impacts to the ecological functions provided by the Cedar River. Fish and Wildlife Use The Cedar River provides habitat for resident and migratory salmonid species including sockeye (Oncorhynchus nerka), coho (Onchorhynchus kisutch), Chinook (Oncorhynchus tshawytscha), cutthroat trout (Oncorhyncus clarki), kokanee (Oncorhyncus nerka), steelhead (Oncorhyncus mykiss), Dolly Varden (Salvelinus malma), and bull trout (Salvelinus confluentus). Other documented fish species in the Lower Cedar River watershed include mountain whitefish (Prosopium williamsoni), northern squawfish (Ptchochelius oregonensis), several species of sculpin (Cottus sp.) and western brook lamprey (Lampetra richardsoni). Observations on e-Bird for the Renton-Cedar River Trail (on the east side of the river, opposite from the Renton Municipal Airport) included typical urban species including American crow, European starling, Canada goose, mallard, dark-eyed junco, song sparrow, spotted towhee, red-winged blackbird, American goldfinch. Waterfowl (including western grebe, ring-billed gull, double-crested cormorant, red-breasted merganser, and various species of ducks) and raptors (osprey, bald eagle and Cooper’s hawk) were also reported. There are no known nests or feeding/foraging areas in the vicinity of the project area. The proposal will not impact fish or wildlife species. Construction activities may result in temporary noise impacts which may result in bird species temporarily avoiding the project area. DATE: July 22, 2024 SUBJECT: Renton Aprons – Stream Assessment Narrative MEMORANDUM Page 2 of 2 However, the project is in an urban area and species in this area are already subject to noise from urban and aviation activities. Therefore, construction noise is not anticipated to result in any significant disturbance to any species. Tree Protection Measures The project does not include any tree removal. Therefore, no tree protection measures are required. No Net Loss of Ecological Functions The project will not alter the existing conditions and will not result in any impacts to the Cedar River. Therefore, the project will not result in any loss of ecological functions and is compliant with the No Net Loss requirements described in RMC 4-3-090D2.