Salmon flourished after Pilchuck River Dam’s demolition

The concrete dam across the Pilchuck River was punctured and dismantled in summer 2020.

The concrete dam across the Pilchuck River was punctured and dismantled in summer 2020.


SNOHOMISH — The fruits of removing a dam on the Pilchuck River in 2020 came quickly.
Straight away, the first Chinook salmon were spotted about a month later.
They have re-habitated the area during spawning season even though it's been generations since they might have roved these waters.
The dam across the river dated to 1932.
When the dam was in place, Chinook and pinks (humpback) salmon would try jumping it to proceed upstream but fall back. (Coho salmon could make the leap.)
The dam by Granite Falls was there to divert drinking water for the City of Snohomish. But by the mid-2010s, the city got all its water from Everett. The city no longer employed its use.
The Tulalip Tribes worked with the city to get rid of it.
The dam's removal gave salmon access to 37 miles of streams and creeks upstream for the first time in decades, Brett Shattuck, a restoration ecologist with the Tulalip Tribes explained.
Salmon are explorers. As needed, they’ll venture up streams to seek new spawning grounds. Up came pinks, Chinooks, and chum salmon as well as steelhead.
“We’re seeing virtually all the salmon species that use the Snohomish River basin” now in this part of the Pilchuck River, Shattuck said.
Chinook and steelhead both are considered endangered species.
Any barrier removed is good, said Tom Murdoch, the executive director of the Adopt A Stream Foundation who’s worked as a stream ecologist since 1978.
With the Pilchuck River, its water systems are rural, giving young salmon better survival odds, Murdoch said.
“Removing this dam is great because salmon can go up to streams where these areas are conditioned” for a good habitat, Murdoch said.
The further away from people, the better for them.
Experts calculate the Pilchuck River produces maybe 250 Chinook salmon a year.
There were not specific goal numbers for how many salmon would spawn in the upper Pilchuck system, Shattuck said. The goal itself was to remove non-natural barriers to the Pilchuck upper waters. The river’s start is south of Verlot in the foothills of Mount Pilchuck.
Additionally, removing the dam didn’t cause downstream flooding, Shattuck said.


Photo courtesy The Tulalip Tribes

This is said to be the very first Chinook salmon seen in these waters after the dam's removal.

Future work to do
Salmon runs are significantly depressed statewide. There’s a big push to recover their habitat by blowing dams and other big barriers to fish. Enlarging culverts is another piece.
While there isn’t more work immediately in partnership with the City of Snohomish, two areas identified for future salmon restoration projects are near the city’s wastewater treatment plant and at the mouth of the confluence of the Pilchuck and Snohomish rivers, Shattuck said.
More immediately is to work on the Pilchuck River Basin downstream of the dam to remove the rocks that were embedded in the riverbanks.
There is also work to be done on Bunk Foss Creek and Sexton Creek, Shattuck said. The latter is in the Pilchuck River’s stream network.
What’s more, projects are pushing back and reducing the size of levees. A major undertaking on Smith Island was finished in the past few years, and work is being done now to lower the levee at Thomas’s Eddy.
The purpose of lowering levees is to allow floodwater to spread out during flooding times. The effect slows down water current when it floods; a slowdown prevents the current from damaging salmon spawning nests called redds.
The Tulalip Tribes have invested heavily toward salmon preservation projects across Snohomish County like this because the tribes took care of these areas. The tribe has “a huge interest in retaining resources” to prevent depletion of salmon, Shattuck said.
Tribal members haven’t harvested river fish for over a decade, but do harvest the salmon which come back to hatcheries, Shattuck said.
The Snohomish River doesn’t necessarily have barriers in the main river system, but there are thousands of fish passage barriers in the smaller stream systems that feed the Snohomish, Shattuck said.
Chinook production in the much broader Snohomish River basin, which includes the Snoqualmie and Skykomish rivers, has been decimated to 10% of its historical salmon run, a 2005 report says.
In Monroe, Murdoch is eyeing a project to remove a disused railway trestle over Woods Creek. The trestle’s legs underneath are narrow and tend to get clogged with river debris easily, posing a fish barrier there. Trains now travel a newer bridge nearby.
More information about the Pilchuck Dam Removal project is at www.pilchuckriverdam.com