State Route 516 in Des Moines will be reduced to one lane with alternating traffic on weeknights starting Tuesday, Sept. 5, until Friday morning, Sept. 15, for work on the Barnes Creek fish passage project.

Construction is not planned during the weekend.

From 9 p.m. to 5 a.m. nightly, contractor crews working for the Washington State Department of Transportation (WSDOT) will close one lane of SR 516 between South 230th Street and 16th Avenue South. Flaggers will alternate traffic through the work zone near Barnes Creek.

Crews will use the overnight closures to perform earthwork around Barnes Creek. The work will prepare the area for a nine-day full closure of SR 516, tentatively set for Sept. 15-24.  During the closure, crews will remove a failing clay culvert that blocks fish passage and install a new cement box culvert that fish and other wildlife can use.

The detour route for the full closure uses Marine View Drive, South 240th Street and 16th Avenue South.

For the latest construction closure information, visit WSDOT’s real-time travel map, download the WSDOT mobile app or sign up for WSDOT’s email updates.