The California water board has approved a plan for water releases into the Sacramento River that could kill off an entire run of endangered chinook salmon and put at risk another population that is part of the commercial salmon fishery.

The State Water Resources Control Board has informed the federal Bureau of Reclamation it would accept its final plan for managing water flows from Shasta Lake into the Sacramento River, which is both the main source of water for Central Valley farms and the spawning habitat for chinook salmon. Because the bureau’s plan involves releasing water to irrigation districts earlier in the season, the river will be lower and warmer during salmon spawning season and could result in killing as many as 88% of endangered winter-run chinook eggs and young fish.