Feb. 26, 2026

By Michael Wright 

A federal judge in Oregon has ordered changes to dam operations on the Columbia and Snake rivers to help salmon runs.

In a ruling released Wednesday, U.S. District Judge Michael H. Simon toldfederal agencies that run eight dams on the two rivers to spill more water over the top of the dams and maintain reservoir levels at the height they were last year.

Increasing spill is meant to help young salmon on their way to the ocean pass over the top of the dams rather than swim through a gauntlet of turbines that are known to kill them. Reservoir levels affect the speed of salmon migration.

The decision marks the latest turn in a decades-long legal fight over the dams and their impact on the salmon and steelhead that migrate between the ocean and their natal streams in Washington, Oregon and central Idaho.

In 2023, under the Biden Administration, the plaintiffs agreed to halt the litigation in exchange for $1 billion in federal money for fish habitat and energy projects. The Trump administration canceled that deal, prompting the plaintiffs to resume their legal fight.

Last year, Tribes, fishing groups and conservationists, represented by the environmental law firm Earthjustice, requested the changes to dam operations as part of a preliminary injunction request. The state of Washington filed an amicus brief supporting the injunction.

Simon’s ruling didn’t give the plaintiffs everything they wanted, but he wrote that action is needed due to the “dire situation” facing the 14 endangered and threatened salmon and smelt species in the Pacific Northwest.

He wrote that there’s a “disappointing history of government avoidance and manipulation instead of sincere efforts at solving the problem and genuinely remediating the harm.”

“One of the foundational symbols of the West, a critical recreational, cultural, and economic driver for Western states, and the beating heart and guaranteed resource protected by treaties with several Native American tribes is disappearing from the landscape,” Simon wrote.

Amanda Goodin, the Earthjustice attorney who represents the plaintiffs, said in a statement that the changes the court ordered “are immediate and reasonable steps to prevent salmon extinction.”

Abbie Abramovich, the Idaho Conservation League’s salmon program senior associate, said in an interview that the changes at the dams are doable and will help fish get to prime habitat in places like the Clearwater and Salmon rivers and their tributaries.

“Idaho holds some of the best habitat in the Lower 48, which includes cold mountain streams,” Abramovich said. “We just have to give these fish an opportunity to reach it.”

Still, she said, the ruling isn’t a permanent solution.

“This is basically life support that we’re offering these fish,” she said. “It’s entirely possible for the northwest to have clean energy and recover salmon populations, and this ruling is an important step in that direction.”

Republican politicians, agriculture groups and others criticized the decision. They raised doubts that it would help fish and characterized the ruling as a threat to the system’s dams.

“These vital pieces of infrastructure allow irrigation and navigation for farmers, their commodities, and many other products that move on the rivers,” U.S. Rep. Dan Newhouse, R-Washington, said in a statement. “The dams and salmon can, and do, coexist, and I remain committed to ensure the system has the resources needed to improve fish passage at lower spill levels.”

Idaho Republican Gov. Brad Little said in a statement that the decision is a “direct attack on agriculture and Idaho’s energy security.”

“Idaho will not stand by while decisions made outside our borders put our public safety and economy at risk,” Little said. “… Our people depend on the Columbia River System, and we will fight to ensure Idaho meets the real-world energy demands of today and tomorrow.”

Wednesday’s ruling affects operations at four dams on the lower Columbia – Bonneville, the Dalles, McNary and John Day – and four on the lower Snake – Ice Harbor, Lower Monumental, Little Goose and Lower Granite.

The plaintiffs’ injunction request sought a suite of emergency conservation measures, such as ordering the defendants to remove salmon-eating predators, in addition to the operational changes at the dams. Simon declined to order the conservation measures, instead narrowing the decision’s mandates down to reservoir levels and spill operations.

The plaintiffs had asked the judge to order dam operators to keep reservoirs at their minimum operating levels, arguing that doing so helps fish migrate to the ocean faster. The defendants argued that operating reservoirs at the minimum level could harm dam operations.

Simon ordered the levels be maintained where they were in 2025 – a level higher than plaintiffs wanted but lower than what is allowed. He wrote that the dams operated successfully at those levels last year, meaning “all parties can be assured of the viability of the operations for power generation, transportation, and irrigation.”

The spill increases direct dam operators to spill water over the top of the eight dams 24 hours a day from spring to mid-November, with a winter shutdown period between mid-November and late February.

At Little Goose Dam, spring spill hours will shorten based on the number of adult chinook salmon that cross the dam.

The volume of spill required changes by seasons. The highest spill amounts are set for the spring, starting in April. Spill will be reduced some in mid-June, and then reduced to their lowest level on Sept. 1.

In the past, summer spill levels were reduced at the end of July.