Phase 2 - Madison Valley Stormwater Project
In June 2008, the Seattle City Council and the Mayor authorized SPU, via City Ordinance, to design and construct a pipeline in the NW section of the Madison Valley basin that will collect and convey stormwater to a new storage system in Washington Park.
View Ordinance (pdf)
The location of the stormwater pipeline was determined based on engineering factors as well as impacts to community, cost and schedule constraints. The storage system in Washington Park has been designed to hold 2.2 million gallons of stormwater with approximately half of the storage capacity in a mostly below-ground tank and half in an above-ground landscaped area. Based on modeling results, stormwater would only appear in the Washington Park above-ground holding area during especially large storms like the August 2004 and December 2006 storms. Stormwater will flow from the storage system to the combined sewer system as soon as capacity is available, typically within hours after heavy rain storms.
SPU hosted three public meetings in 2009 at different stages of the design to get input from the community and stakeholders.
Construction of Phase 2 is expected to begin in summer 2010, and take 15-18 months to build.
- Graphic overview of the project with pipeline route (pdf)
- Graphic of landscape plan (pdf)
- Graphic of landscape details (pdf)
- Phase 2 - Art Wall (pdf)
- Project Schedule (pdf)
Public Art for Madison Valley Stormwater Project will be created by artist Adam Kuby.