Click on this image for a time-lapse video of the box culvert's installation.
Update (August 29) -
Lake Washington Boulevard has reopened south of Northeast 38th Place. Please use caution while drive through the construction area as flagging operations and lane closures will continue through September. Thank you for your patience.
The 900-foot section of Lake Washington Boulevard between Northeast 38th Place and Northeast Points Drive will have just one travel lane open in each direction starting Aug. 15 and ending Sept. 23.
KLB Construction, Kirkland’s Cochran Springs culvert replacement contractor, will be using the remaining space—including the bike lanes—to prepare Lake Washington Boulevard for the 15-foot-wide by seven-foot-tall box culvert its crews will be installing in Cochran Springs Creek during the five consecutive days that begin with Aug. 26.
Although emergency responders will have access to the area during this five-day, full-closure, all other commuters—including those who travel by foot, by bike, by car or by bus—will, for the sake of safety detour around the closed construction zone by either traveling south along Northeast 38th Place or north along Northup Way.
During the five weeks of lane closures, however, the project will accommodate all forms of travel. The two on-street travel lanes will be 14 feet wide, wide enough, according to state regulations, for car and bike travel. And the project will keep open a sidewalk—either on the south or north side of the road.
The closures are part of a project to replace a pair of 24-inch culverts at Cochran Springs with a box culvert that is 15 feet wide and five feet deep.
The City will be removing an estimated 2The 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 Lake Washington Boulevard.
Top photo: City of Kirkland Project Engineer Patrick Herbig measures the depth of sediment that has accumulated downstream of a pair of culverts on Cochran Springs, near Northup Way
. Bottom photo: Herbig inspects a box culvert that conveys a creek beneath Lake Washington Boulevard, just north of the Highway 520 interchange. Herbig is the City of Kirkland engineer on a project to replace a pair of small culverts on Cochran Springs, pictured in the left image, a few hundred yards to the north—with a box culvert similar to the one pictured here.