A conservation group is suing the U.S. Army Corps of Engineers, saying the agency is polluting the Columbia River with hot water, oil and toxic chemicals that are killing large numbers of endangered salmon.
Columbia Riverkeeper filed the lawsuit Wednesday in federal courts in both eastern Washington and Oregon.
The lawsuit contends four dams operated by the Army Corps on the Columbia River between Portland and the Tri-Cities of Richland, Pasco and Kennewick in Washington discharge illegal pollution in violation of the Clean Water Act.
The dams make the water too hot for endangered salmon and steelhead to survive, the lawsuit said.
The lawsuit contends the corps failed to obtain permits that would place regulatory limits on its discharges of heated water, grease and oil from the dams. The Clean Water Act prohibits discharges of pollutants in federal waters unless permitted.
“Salmon are dying because the water is too hot. It’s past time for the Army Corps to reduce illegal heat pollution from dams,” said Brett Vanden Heuvel, executive director of Columbia Riverkeeper. “No one is above the law."
The corps issued a statement saying they take seriously the obligations of the Clean Water Act.
"Our team is working tirelessly to find solutions that balance all of the purposes of the system, including the needs of fish and wildlife, flood risk management, navigation, power generation, recreation, water supply, and water quality,” the agency said in a statement from its Portland office.
“Although the pools behind the Lower Columbia River dams are considered reservoirs, they are largely not storage reservoirs, but rather run-of-river facilities,” the corps said. "This limits our ability to impact water temperatures by drawing down water levels in the spring.”
The dams involved are Bonneville, The Dalles, John Day and McNary, Columbia Riverkeeper said.
The lawsuit was filed in both Oregon and eastern Washington because the dams touch the borders of each state as they straddle the Columbia River, the environmental group said.
The lawsuit said the Columbia River “is one of the West’s great river systems. This river supports rich fishing traditions, provides water for communities and agriculture, supports recreation opportunities, and powers hydroelectric dams."
But the lawsuit noted that in 2015, water reached temperatures warm enough to kill thousands of migrating sockeye salmon.
“Scientists estimate that more than 277,000 sockeye, about 55 percent of the total run returning from the ocean to spawn, died in the Columbia and Snake Rivers due to warm water temperatures” that year, the lawsuit said.