SR 169 to close for 35 days near Black Diamond for fish passage improvements

Construction starts Aug. 17 near Jones Lake as work begins on multi-year culvert replacement project

BLACK DIAMOND - Construction starts Monday, Aug. 17, on a fish barrier removal project in Black Diamond. The work requires a 35-day closure of State Route 169 near Jones Lake.

Over the next two years, contractor crews working for the Washington State Department of Transportation will replace culverts at five locations along SR 169. The new fish passable structures will open 4.6 miles of potential upstream habitat across five waterways.

This project will require separate extended closures on SR 169 in 2026 and 2027. Signed detours will guide people around the closures.

What to expect in 2026

Starting at 12:01 a.m. Monday, Aug. 17, both directions of SR 169 will close between Southeast 332nd Street and Plass Road. All lanes are scheduled to reopen Sept. 21, pending favorable weather and site conditions.

Here is what people can expect during the 35-day road closure:

• Separate signed detour routes for passenger vehicles and freight vehicles.
• SR 169 limited to local access only between Roberts Drive and Southeast 332nd Street, and Southeast Green Valley Road and Plass Road.
• People who live along SR 169 will have access to their driveways.
• Businesses along this section of SR 169 will be open and accessible.
• Cyclists and pedestrians must follow detour routes.

During the 2026 construction season, crews will replace two culverts near Jones Lake, south of Black Diamond's historic downtown. In 2027, crews will correct a third culvert near Jones Lake and two additional culverts near the SR 169 intersection with Black Diamond-Ravensdale Road.

Construction will pause from fall 2026 until spring 2027, when work resumes on the three remaining waterways. More details on the 2027 construction schedule and detour information will be released early next year. All construction is expected to finish in October 2028.

Improving waterways beneath SR 169

This project will improve fish passage on Rock Creek, two unnamed tributaries to Jones Lake, Ginder Creek and an unnamed tributary to Ginder Creek. Crews will remove existing pipe culverts beneath SR 169 that prevent fish from swimming upstream. They will replace them with three-sided concrete culvert structures ranging from 16 to 55 feet wide.

Crews also will make habitat improvements in each location and restore natural stream conditions where each waterway flows beneath SR 169.

This project supports WSDOT's ongoing commitment to improve fish passage beneath state highways and restore salmon and steelhead habitat under a 2013 federal court injunction.