PORTLAND — A U.S. appeals court on Monday affirmed an order to spill more water over Columbia and Snake river dams to help protect salmon and steelhead and aid their migration to the sea.
The decision came after U.S. District Court Judge Michael Simon of Oregon ruled last spring that the U.S. Army Corps of Engineers must spill more water through spillways rather than turbines that pose a danger to the fish.
He sided with conservationists who say allowing extra water to flow between April and mid-June will help young salmon.
The Army Corps, National Marine Fisheries Service and another federal agency appealed Simon's ruling.
A three-judge panel of the 9th U.S. Circuit Court of Appeals said Monday that Simon rightly concluded that the salmon and steelhead are imperiled and will remain so without further conservation efforts.
The judges also pointed to decades of studies that show higher spill volumes lead to increased survival rates.
"At best, federal defendants establish uncertainty about the benefits of increased spill, but the existence of scientific uncertainty does not render the district court's findings clearly erroneous," Chief Judge Sidney Thomas wrote in the opinion.
The new spill operations are set to begin Tuesday at some dams on the Snake River and next week on some dams in the Columbia, one of the largest rivers in North America. The Snake is its largest tributary.
Conservation groups said it's the fourth time since 2005 that increased spill has been mandated by the district court.
"It's tragic that the federal agencies are still ignoring their own science in fighting spill at every step of the way," said Glen Spain, Northwest regional director of the Pacific Coast Federation of Fishermen's Associations.
Corps spokesman Matt Rabe declined comment on the litigation. He said the corps will follow the ruling and increase spill Tuesday.