We're very excited that the King County Wastewater Treatment Division and King County Executive Dow Constantine have recommended that Green Stormwater Infrastructure be used to control CSO Overflows from the Barton pump station in West Seattle. In doing so, they are leading the way nationally in thinking about how we invest in a systematic changefor retrofitting CSO infrastructure.
For a number of months, we have been working with the Carollo and Tetra Tech team to evaluate the feasibility of this "demand management" solution by retrofitting the neighborhood with roadside raingardens. In addition to the primary benefits of reducing discharge of sewer overflows into Puget Sound, there are benefits to stormwater management, habitat, the neighborhood streetscape and community connections to the biological world . Incorporating green infrastructure will also result in a great walking environment for the residents in the area.
The County's press release (via the West Seattle Blog)
The [Barton] project would employ a system of rain gardens and swales – known as a Green Stormwater Infrastructure (GSI) project – between the sidewalks and streets in the Sunrise Heights and Westwood neighborhoods to reduce overflows from the Barton Pump Station near Seattle’s Lincoln Park....
During heavy rains, the GSI alternative would control CSOs at Barton Pump Station using soils and vegetation to capture and reduce stormwater that would enter the conveyance system. The area’s gentle topography and the connection of street drains to the combined sewer system make the alternative technically feasible.
West Seattle neighbors expressed support for this enviro
nmentally friendly solution, which also supports the County’s commitment to energy conservation and sustainability.
In a letter to the residents of the area, Christie True, Director of the County's Department of Natural Resources writes about the Barton Basin Project:
A green infrastructure project for the Barton Basin will consist of planted areas between sidewalks and curbs in the Sunrise Heights and Westwood neighborhoods of West Seattle. Also known as "rain gardens," these planted areas will be constructed in the city-owned right of way. The rain gardens are designed to reduce CSO overflows by capturing and infiltrating rainwater that would otherwise enter our
sewer system. This area is uniquely suited for this type of project because of its gentle topography and the connection of street drains to the combined sewer system.
The project offers these important advantages:
- Vegetation allows stormwater runoff to infiltrate into soil rather than entering the combined sewer system. By maximizing use of natural processes, the project supports the region's commitment to energy conservation and sustainability.
- King County will work with the neighborhood to enhance street aesthetics, minimize parking impacts, and respond to neighborhood preferences for the project.
- The project does not require any operating facilities, and responds to many West Seattle residents who expressed strong support for a "green" solution.
- This approach significantly reduces the risk of combined sewer overflows at Barton and reduces flows to the Murray Basin.
These are very exciting developments and we congratulate everyone who worked long and hard on these difficult decisions.