The Fish and Wildlife Service proposed Endangered Species Act protections Thursday for a crucial population of the longfin smelt, an unassuming California fish that has pit farmers against environmentalists and could end up redirecting the future course of the state’s water.

Reversing earlier calls made during both the Obama and Trump administrations, FWS said the San Francisco Bay-Delta distinct population segment of longfin smelt should be added to the list of endangered species.