Drivers should expect more construction and disruptions on state Route 169 for the near future.

First, Roberts Drive in Black Diamond closed on March 24 for four weeks.

This is a continuation of the roundabout project that has been tearing up the highway since the fall of 2023; lanes are being moved to the east side of the highway so workers can construct the western half of the roundabout at Roberts Drive.

Once Roberts Drive opens again in early May, the first of the two roundabouts will be finished; it’s expected to be one more year before the $10 million project is complete.

The city recommends the detours on SE 288th Street to 126th Avenue SE to Lake Sawyer Road, or Jones Lake Road to Morgan Street.

Note that Jones Lake Road has a 20,000 pound weight limit for large trucks.

FISH CULVERT REPLACEMENT UPDATE

Once the roundabouts are completed, the Washington State Department of Transportation is coming in to replace several fish culverts — some underneath SR 169 near the south border of Black Diamond by Jones Lake (called the Rock Creek culverts), and the rest are underneath the soon-to-be-finished roundabouts to the north (at Ginder Creek).

According to the state, these culverts are failing and prevent migrating fish from passing through. WSDOT is required by a 2013 Washington State Supreme Court injunction to repair fish culverts around the state.

The state estimates repairing these culverts will result in a potential habitat gain of 4.6 miles.

Work was originally expected to begin at Rock Creek sometime this year, but estimates have been pushed back to 2026.

Work on Ginder Creek is also expected to start in 2026, after the roundabouts are completed.

It’s not known how these projects will affect traffic at this time, but work on these projects can take up to two year.

The whole project comes with a $73 million price tag.