Three environmental groups and two commercial fishing advocacy groups say they will file a lawsuit against the federal government over heat-related fish kills in the Columbia River Basin in the Pacific Northwest.
The groups on Monday sent a 60-day notice of their intent to sue the U.S. Environmental Protection Agency for what the groups say are violations of the Clean Water Act.
The groups say 250,000 adult sockeye salmon died in 2015 due to high temperatures in the Columbia River and lower Snake River.
Idaho Rivers United, the Pacific Coast Federation of Fishermen's Associations and the other groups say a die-off could happen again.
The groups say the federal agency has failed to create a plan to control water temperatures.
An EPA spokeswoman didn't immediately return a call from The Associated Press on Monday.