Evans Creek Tributary 108 Small Stream Basin Retrofit
The Evans Creek Tributary 108 is located in the Northeast Quarter, Sections 4, 5, 8, and 9, Township 25, Range 6 East WM, in King County. Tributary 108 is within the Bear-Evans Creek watershed.
This project was partially funded by Washington State Department of Ecology (Ecology) Grant. Evans Creek was selected for this project because it has a high score on Ecology’s Watershed Integrity Index and ranked high on the County’s list of Small Basins for Retrofit.
The basin is approximately 397 acres, dominantly Alderwood and Everett soils, and surface area of approximately 37 % forest and 16% impervious area. The Tributary 108 basin has experienced a significant amount of development that occurred before adequate stormwater controls were required on new development, which has degraded the tributary's water quality/health and contributed to documented degradation of Evans Creek.
The purpose of this project is to conduct small basin stormwater retrofit planning and design.
- Identified a retrofit blueprint for the entire stream basin, including prioritization criteria that can be used to guide future capital investments. Refer to the Evans Creek Task 4 memo document (2.9 Mb pdf).
- Produced pre-design reports for retrofit project Northeast 87th Place (4.4 Mb pdf) verifying the costs, benefits and readiness of this project
- Shared results and lessons learned from the new systematic design approach through presentation to the American Public Works Association Stormwater Managers (13.3 Mb pdf).
- Received Ecology Stormwater WQC-2016-KCWLRD-00056 grant for NE 76th Place and NE 78th Street detention vaults.
NE 76th Place and NE 78th Street Detention Vaults Stormwater Retrofit
This project will improve water quality in the Evans Creek Tributary 108 through installation of detention vaults in the right of way, in between house addresses 20620 and 20626 NE 76th Place and in front of house address 20508 Northeast 78th Street near Redmond, in unincorporated King County. This project will reduce peak flows and sediment loading to Evans Creek Tributary 108 by providing stormwater detention. This project is partially funded by the Washington State Department of Ecology Water Quality Combined Financial Assistance Grant WQC-2016-KCWLRD-00056.
Summary milestone schedules
- Complete Construction of Project by November 1, 2017