The Biden administration today will declare a water shortage on the Colorado River for the first time ever, triggering cutbacks in the Southwest due to a decadeslong drought that experts say is a sign of what’s to come.

Bureau of Reclamation officials will announce that water levels in the river’s main reservoirs have dropped so low they have triggered mandatory delivery reductions in Arizona and Nevada.

The announcement comes as heat waves and wildfires are scorching the West, presenting the Biden administration with another crisis. A 20-year “megadrought” in the seven-state Colorado River Basin has caused Lake Mead and Lake Powell to drop to levels not seen since they were originally filled a half-century ago.

“This drought has come on faster and harder than last time,” said Ellen Hanak, the director of the water policy center at the Public Policy Institute of California, referring to the last Golden State drought that ended in 2016. “We are in year two, but we’re in as bad a shape as year three of what was a record drought last time.”