Washington’s newest mega project: Fish barrier corrections

By Ann Briggs

You've probably heard about our four “mega projects:” Alaskan Way Viaduct, State Route 520 Bridge, Interstate 405 Corridor and the North Spokane Corridor, but did you hear about the newest one? It's called “Fish Passage” and it's currently unfunded.

Statewide, there are about 6,500 culverts on the state highway system. Of those, about 3,200 are in fish-bearing streams. We're required by law to maintain culverts, fish ways and bridges so that fish have unrestricted passage to upstream and downstream habitat.

SR 530 Moose Creek culvert before correction.

A recent federal court injunction requires the state to step up its fish barrier corrections in the northwest part of the state. About 989 culverts are affected by this court action, with 825 of them having significant habitat. To comply with the injunction, we'll need to fix about 30 to 40 barriers each year for the next 15 years.

The amount available for this work in the current biennium is $36 million. Right now we estimate approximately $300 million is needed each two-year budget cycle through 2029-31. The initial estimated cost to comply with the injunction is $2.4 billion at the low end, and likely to go up. As we do more detailed design work on a first round of 34 projects, we are finding that costs are higher than initial estimates for those projects. That's mostly due to limited site-specific information when the initial cost estimates were developed. We anticipate cost estimates for the entire program will stabilize as we learn more about individual site characteristics.

We've been working to improve access to habitat for fish since the 1990s. About 280 fish-barrier correction projects have opened access to more than 975 miles of potential fish habitat.
SR 530 Moose Creek culvert after correction.

Why do we do this? It's part of our agency's goals to protect natural habitat and water quality. It also supports the Governor's goals for the environment and salmon recovery.

So how did we get here? You have to remember that much of our state's infrastructure was built decades ago. Many of these culverts were installed simply for the purpose of conveying water, before we had the science and understanding of the needs of fish.

In some areas, like Interstate 90 at Snoqualmie Pass, projects that improve fish passage have improved conditions for other species, allowing deer, bear and other wildlife to cross safely under or over the busy freeway lanes – that's safer for drivers too!

Visit our Fish Passage project website for an interactive map of all barrier locations and project details.