The U.S. government released projections Wednesday that indicate an even more troubling outlook for a river that serves 40 million people in the American West.

The Bureau of Reclamation recently declared the first-ever shortage on the Colorado River, which means Arizona, Nevada and Mexico will get less water than normal next year. By 2025, there’s a 66% chance Lake Mead, a barometer for how much river water some states get, will reach a level where California would be in its second phase of cuts. The nation’s most populated state has the most senior rights to river water.