Project overview
Reconnecting waterways where our roads act as barriers is a priority for the state. In western Washington, that means building hundreds of fish passable structures under state highways to create habitat essential for meeting fish recovery goals. Beginning as early as winter 2024, WSDOT will install a new fish passable structure that will carry Tibbetts Creek under SR 900 north of Squak Mountain State Park.
What to expect
WSDOT will select a qualified design-build contractor to complete the design of the fish passable structure for Tibbetts Creek under SR 900. Highway closure needs will be determined by the type of structure and the construction method proposed by the contractor.
This project is being combined into a single contract with other fish passage projects on I-90. Because of the multiple locations, we can’t say at this time when the work will occur on SR 900. Work could begin as early as spring 2024. We anticipate work at this location to be between three months and one year, depending on the structure and the construction method.
A map showing the location of the culvert carrying Tibbetts Creek under SR 900 near Squak Mountain.
To protect and restore fish runs, WSDOT is correcting fish barriers found under state highways. Since 1991, when WSDOT created a dedicated program, 365 barriers have been corrected, opening a total of 1,215 miles of fish habitat.
Replacing the culvert that carries Tibbetts Creek under SR 900 with a new fish passable structure increases the likelihood of fish migration.
Opening habitat allows more salmon and steelhead at all life stages, including juveniles that aren’t yet strong swimmers like adults, to access important spawning and rearing habitat, including areas that haven’t been accessed in years.
Improvements to fish passage also benefits commercial seafood operations, recreational fishers, and provides more food for our declining orca population. In addition, replacing these culverts helps us meeting our obligation to remove barriers under a 2013 U.S. District Court injunction.
About the creek
Tibbetts Creek travels under SR 900 at milepost 19.5, north of Squak Mountain State Park. The existing culvert is only considered 33% passable, making it difficult for coho, resident trout, steelhead, sockeye and sea-run cutthroat to successfully navigate up and downstream. Replacing the existing culvert with a new fish passable culvert will result in a potential habitat gain of 1,763 meters.
