The City is currently working on a Basin Plan for Ecology approval that will document the design of various regional stormwater facilities proposed within the Overlake neighborhood.
2010. Following the Overlake Neighborhood Plan update, the City adopted an Implementation Plan to guide the City in its objective to improve management of stormwater within the Overlake neighborhood. This plan focused on the commercial and employment areas of the neighborhood that are zoned for the highest density of development. The plan was developed to implement policies of the Overlake Neighborhood Plan. The proposed stormwater facilities and some new streets were further defined by the Overlake Village Street Design Guidelines, adopted by City Council in April 2011.
2012-2013. Overlake Village LID Retrofit. The first investment the City made in improving stormwater in this neighborhood is construction of rain gardens in existing streets where there was more pavement than needed for transportation demands. Removed pavement was replaced with attractive and functional rain gardens that provide stormwater treatment and flow control to protect creeks downstream from urban runoff. These improvements made the area more pedestrian friendly and give a peek into the future of the Overlake Village.
2013-2015. Overlake Village South Detention Vault. The first large stormwater facility is a regional detention facility that detains stormwater that has been treated locally within public rights-of-way and private development areas. Once surrounding property develops in the future, park facilities will be constructed on top of the stormwater vault. In the meantime, parking use will continue by the owner of the property. Utility relocations to accommodate the new vault were completed in 2013. The first cell of the vault was made operational in late 2014 and the vault construction will be complete in 2015.
2016-2018. Overlake Village Station Infiltration Vault. The second large stormwater facility proposed is a regional infiltration facility that will provide retention of stormwater and treatment by infiltrating the stormwater into the ground. This facility is proposed for construction in coordination with the Sound Transit East Link Light Rail, proposed to open in 2023. The City has to come to agreement with Sound Transit; the City will pay Sound Transit to finish design and build the project as part of the light rail project. This vault is scheduled to be operational by 12/31/2017.
2025. Overlake Village Central Infiltration Vault. The third and final large stormwater facility will occur as redevelopment occurs in the future. This large facility will complete the retrofit of the Overlake basin to current stormwater runoff treatment and flow control standards. A two acre park will be constructed on top of the stormwater vault, surrounded by new streets, (NE 26th Street, NE 27th Street, 151st Ave NE, and 152nd Ave NE). It is expected that private development will be triggered by the opening of the new light rail station and that this facility will be constructed in the mid to late 2020s.
2030. The urban pathway connecting the three large stormwater sites is intended to be developed within dedicated easements adjacent to City rights-of-way, and would be designed to include low impact development (LID) components. As public and private development move forward, these infiltrating, smaller-scale stormwater facilities will allow more efficient use of the large regional stormwater facilities and will help create much improved flow conditions in the streams where this stormwater flows.