California is fighting a plan by President Donald Trump’s administration to push more water through the Delta – a move state officials say would harm endangered fish species and deprive millions of Southern Californians of water.

The state Department of Fish and Wildlife, in a letter to the U.S. Bureau of Reclamation, said the federal plan would harm the nearly-extinct Delta smelt and other species. The state said the plan would also hurt the mostly urban water agencies that belong to the State Water Project, which might have to surrender some of its supplies to compensate for the federal plan.