The coho salmon has already conquered the Ballard Locks fish ladder, swum 17 miles through urban Seattle waterways and powered through a tunnel under nine lanes of Interstate 405.
It faces a gantlet of pipes and concrete tunnels ahead, the legacy of human development over once-pristine habitat. Next up is a nearly 300-foot pipe beneath an indoor shooting range and a parking lot.
If the coho makes it through, all the way to the upper reaches of this obscure stream in Bellevue, it will find the single most expensive construction project in the state’s costliest-ever salmon-recovery undertaking: $110 million for new bridges to carry Interstate 90 and local traffic high above a restored creek.
But just a third of a mile farther upstream, the fish will slam into a pile of boulders and junk metal, before confronting two concrete pipes perched 5 feet above the streambed. Surveyors determined no salmon could make that leap.
Yet the Washington State Department of Transportation ignored those barriers on Sunset Creek and hundreds of others like them across Western Washington in its massive effort to restore salmon habitat. And the estimate has now doubled to as much as $7.8 billion — the cost of replacing the Highway 99 viaduct along Seattle’s waterfront, twice over, plus change.