Federally-funded Yakima Basin project to save fish by fixing bridge design flaws

YAKIMA COUNTY, Wash. — New funding from the federal government could correct issues with a bridge over the South Fork Tieton River that have led to an accidental, unintentional and seasonal waterfall that can claim the lives of the fish attempting to pass through it.

Assistant Secretary for Fish and Wildlife and Parks Shannon Estenoz visited the site of that bridge Friday morning to share that $400,000 of the new Bipartisan Infrastructure Law will be allocated toward correcting what she called a “bad engineering” decision on the bridge.

“It doesn’t matter if you fish, it doesn’t matter if you grow something: if you live here, you rely on this river,” Estenoz said. “And that’s what this work reflects.”

When the county and federal governments began to replace the decades-old wood trestle bridge over the South Fork Tieton River, they realized the river’s natural channel was bracketed by a slow-moving glacial-clay landslide and weak volcanic rock.

To get around those issues, they filled in the natural channel and split rock down the middle to redirect the river, creating a new channel. However, that placement, now creates a 40-foot waterfall under the bridge every September when the Rimrock Reservoir is drawn down.

Over the years, it’s created a nightmare for any fish looking for safe passage to their spawning area in the reservoir. Authorities said kokanee salmon can’t get through it at all and while some bull trout can make it in, they might not survive the return trip through the waterfall.

“It’s not hard to imagine, if you just look over that bridge, how difficult it would be to navigate that if you were a fish,” Estenoz said. “The idea is to put the river back in its own natural channel, so that that barrier is gone.”

To do that, they’ll be moving the bridge to rest again over the natural channel, which should give fish an easier route to get to where they need to be, wherever that is in the Yakima River Basin.

“It’s going to help the water flow easier; the fish will get past that barrier at low tides or low flows,” Yakima County Commissioner Ron Anderson said.  “And so it’s just going to be a win-win for everybody.”

Phil Rigdon with Yakama Nation Department of Natural Resources said the return to the natural order of things will be a win for the tribe as well.

“These places are sacred to us as a people, Rigdon said. “This brings back the harmony, so that the fish could go back and be a part of the land as they once were.”

The South Fork Tieton Bridge project is still in the planning phases, but officials are hoping to break ground a year from now and have the project completed by April 2024.

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