PROJECT PARTNER(S)
Seattle Public Utilities, Seattle Department of Planning and Development, Seattle Department of Transportation, King County, Washington Department of Ecology, Washington Department of Fish and Wildlife
Consultant Team: SvR Design Company, Associated Earth Sciences Inc., HDR, Inc. LOCATION Northgate Urban Center in the Thornton Creek Watershed, Seattle, WA

GREEN INFRASTRUCTURE ASSETS
Natural Drainage Treatment, Riparian Habitat, Biodiversity, Public Open Space

DESCRIPTION
The Thornton Creek Watershed is a highly developed, urban watershed located in the Northgate Urban Center of northeast Seattle. Urbanization within the watershed has created water quality and flow control problems in Thornton Creek and its tributaries with resultant degradation of the creek’s function as aquatic habitat.

The Thornton Creek Water Quality Channel is a 2.7-acre public amenity and water quality facility that forms part of a larger strategy to revitalize the Northgate Urban Center. The facility has 2 overarching goals:
1. Improve stormwater entering Thornton Creek by enhancing water quality, as well as by slowing down and infiltrating flows from smaller frequent storms; and
2. Provide a safe and pleasing public open space that is integrated with the immediately adjacent “Northgate Commons” mixed use residential project as well as surrounding streetscapes.

It is designed to treat runoff generated from an 680 acre area during small, high-frequency storms; and it is intended to remove pollutants from stormwater by slowing urban runoff before these flows enter the lower reaches of Thornton Creek. Treated stormwaters derive from several adjacent sources: Interstate 5, North Seattle Community College campus, Northgate Transit Center, Northgate Mall, and nearby arterial streets.

The facility, which provides habitat and functions as a bioswale, provides large-scale natural drainage treatment in a public setting by mimicking the structure of a natural stream bed and riparian zone. It is integrated into adjacent commercial and transit-oriented mixed-use development by providing a central public open space as well as pedestrian connectivity to an adjacent regional transit hub.

The facility was constructed by Seattle Public Utilities with funding support from Washington State Department of Ecology via a Washington State Water Pollution Control Revolving Fund Loan.

Link to: Thornton Creek Water Quality Channel, Final Report (October 28, 2009):
http://www.seattle.gov/util/stellent/groups/public/documents/webcontent/spu01_006146.pdf

PHOTOS AND DRAWINGS

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LESSONS LEARNED what can we learn from this place? you could address issues of performance, funding, maintenance, interpretation, aesthetics, anything...

ADDITIONAL RESOURCES
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