A fish passage barrier is anything that hinders fish from moving upstream. Culverts, large pipes under roadways, allow water to flow but may not allow fish to swim through. Water might be too swift, too shallow, or has a waterfall into or out of the culvert.
WSDOT corrects fish barriers on state highways to support salmon recovery and comply with state laws. A federal court injunction also requires the correction of barrier culverts to improve fish passage.
New fish passable structures
A new fish passable structure, typically a culvert or bridge, will be installed at each location. Installation can only be done during the fish windows when crews are allowed to work in the water.
The new structures are much bigger than the outdated culverts currently in place. The work will open potential fish habitat upstream. Opening habitat helps fish to thrive, reproduce, and find food and shelter.
The structures are also beneficial to other wildlife besides fish. The larger structures can allow four-legged animals to pass under the highway. Reducing conflicts with wild animals and vehicles is one way to help reduce collisions.
Why close the highway?
Road closure benefits
- Shortens the overall construction timeline
- Minimizes the environmental footprint
- Reduces cost
Why work during the busy summer travel season?
We’re fully aware these proposed closures are planned during the summer travel season. Frankly, we’d do them during the dead of winter if we could. There is a limited time frame when crews are allowed to work in the water. The seasonal “fish window” is a time when this work will be the least disruptive to aquatic life. The fish window is not the same at every fish passage job but is usually in mid to late summer.