The suit said that BPA used a power emergency it declared last April to bypass federally mandated requirements for salmon recovery.

The agency is required by law to treat salmon protection with the same level of importance as hydroelectric power production. The suit accuses the agency of using the emergency declaration to reduce the amount of water that it spilled past hydroelectric dams.

The groups that filed the suit have alleged that the move affected salmon populations, and that juvenile salmon migration this year has been the worst on record.