Big project will restore Yakima River to natural flows between Selah and Union Gap

YAKIMA – Imagine this: A broad boardwalk spanning wetlands with native bird species within eyeshot amid natural foliage and a nearby 8-mile channel filled with fish.

That’s the vision promised by a massive $39 million project aiming to free the Yakima River from the levees that have long constricted it.

The county is the lead on the project dubbed the Gap-to-Gap Ecosystem Restoration Project.

Levees and dikes were built long ago to control the river’s flow as the area was developed. Now the better plan is to allow the river to return to its natural flows, which would cut the hefty cost of levee maintenance and repair and open more than 1,000 acres of natural habitat along the river between Selah and Union Gap, project officials say.

It would also reduce the risk of flooding in crucial areas.

“So you’re changing how things work over a big broad area,” said Yakima County’s water resource specialist Joel Freudenthal.

Interested parties include Yakima County, the U.S. Corps of Engineers, the city of Yakima, the North Yakima Conservation District and the Bureau of Reclamation.

Getting underway

After years of planning, land acquisitions and establishing partnerships with interested parties, the project could see some huge strides this winter with work beginning north of State Route 24.

There, levees will be removed with a new one built hundreds of feet to the east, widening the flood zone and replenishing side-channels near Lake Bucannon and Sportsman Park.

Material from the current levee – about 183,000 yards – will be used to construct the setback and fill mining pits left behind by Central Pre-Mix, said water resource manager Troy Havens.

“There is enough material there to build a whole new setback,” he said.

Next year, probably in October or November, work is expected to begin on levees south of State Route 24.

This phase of the project sets the stage for habitat restoration and a remodel of the lower entrance of the Yakima Greenway trail near Valley Mall Boulevard.

The entrance – now south of the park-and-ride – will be moved to the north. There, the trail will open to a boardwalk that spans wetlands revived by allowing water back into the area.

A gate keeping water from a nearby slough will be reopened, allowing water and fish back into the channel that parallels the river and reaches 8 miles north.

“This should improve fish production in the Yakima Basin as a whole,” said Luke Stilwater, the county’s natural resource specialist.

Making it all happen will be the relocation of a large levee on the east side of the river. That levee will be moved farther east, allowing the river to reclaim its natural path farther away from Interstate 82.

Portions of the Greenway trail hidden by vegetation will be moved into the open, for better visibility, said Greenway Executive Director Kellie Connaughton.

“What that does for our Greenway users is anyone who is using the Greenway is now going to have a true access to a wetlands area,” she said. “There will be wildlife naturally attracted to that type of habitat.”

Flood zone widening

Forcing the river away from some areas over time has made matters worse, county officials have said.

Take the levee east of Yakima’s sewer plant. It’s forcing the river where it bends westward toward the plant. A gravel bar was installed there to protect the plant, but it’s subject to wear and tear and costly repairs.

Moving the east levee farther east will fix the problem, Freudenthal said.

The river will move away from the sewer plant, water velocity and height will drop as a result, and the gravel bar will no longer be stressed, he said.

“It won’t be beating against that levee,” he said.

Over the past decade, the Corps has spent about $10 million on repairs alone, Havens said.

County officials point at the levee near the Terrace Heights bridge is another example.

There, a levee on the east bank is under stress because it tightly channels the river’s flow toward I-82, then into a bend and a tight right turn under the bridge. The restriction on flows creates back pressure around the bridge and sediment backs up as a result.

That’s another problem with restricting a river’s flow – sediment builds up, the river rises as a result and levees need to be raised to accommodate the change.

Part of that levee was set back in 2017 and the rest will be part of the upcoming phase of the project.

The entire project will only enhance the Greenway, which spans the Yakima River from the Selah Gap to Union Gap and westward along the Naches River, Connaughton said.

“It will be just an awesome, awesome enhancement we’re looking forward to,” she said.