Cochran Springs deposits more than 30 tons of sediment each year downstream of these culverts beneath Lake Washington Boulevard. That sediment chokes the culverts and the creek, inhibiting the creek’s ability to convey large amounts of water and the ability of fish to swim upstream through the clogged culverts.
One lane will close intermittently this winter and spring along a short section of Lake Washington Boulevard while the City of Kirkland and other utility operators relocate their respective utilities to make room for a box culvert that will reduce flood risks and improve fish habitat in Cochran Springs Creek.
Lake Washington Boulevard will close completely for 30 days during the box culvert’s installation. Project engineers expect that to happen between July and Sept. 30.
The project will replace a pair of 24-inch culverts at Cochran Springs with a box culvert that is 15 feet wide and five feet deep.
The box culvert will allow City workers to more easily remove the sediment that accumulates on the downstream side of Lake Washington Boulevard. Those sediment deposits smother fish-rearing habitat and cause water in the stream to back-up and, on occasion, flood the roadway.
To install the new box culvert, Kirkland’s contractor will first have to relocate short sections of a pair of water main pipes. Those pipes are on both sides of Lake Washington Boulevard.
The lane closures for Kirkland’s two water mains will begin at the end of January and continue through February. Other utility providers will close a lane intermittently until July.
Starting in July, the City will close Lake Washington Boulevard near Northeast 38th Place and establish a detour route around the project site. The detour route will use Northeast 38th Place, 108th Avenue Northeast and Northup Way. This will alter transit routes.
For up-to-date information, visit kirklandwa.gov/cochransprings