Project overview
In 2021 and 2022, between Maple Valley and Black Diamond we replaced the culvert that carries Ravensdale Creek under SR 169, along with two other nearby culverts. The existing culverts were narrow, which forces the water through too quickly for salmon and other fish to continue upstream.
What to expect
In January 2022 we shifted traffic onto a two-way bypass just west of the current SR 169 roadway. This allowed us to keep people moving along the corridor north of Black Diamond during construction. The new bridge opened to traffic in mid-July 2022 and the pedestrian bridge downstream opened to the public in fall 2022.
Construction affected a few trails in the Ravensdale Creek Natural Area as well. We temporarily closed about a quarter-mile of trails and permanently closed one-tenth of a mile of trail, which is about 0.5 percent of the entire system.
While construction on the road was finished by fall 2022, there was a lot of plant establishment work left to do in late 2022 and early 2023 in the project area. Crews wrapped up punch list items by early fall 2023.
We are working with King County Parks on this project to replace three old culverts in the Black Diamond Natural Area. This will open an additional 2.4 miles of habitat for salmon, steelhead and other fish.
