The Interior Department ordered sweeping new Colorado River water cuts for Arizona, California and Nevada on Friday, as Lake Mead and Lake Powell — the river's two largest reservoirs — sank to their lowest levels since they began filling nearly a century ago.

Under the plan announced by the Bureau of Reclamation, the three states must collectively reduce their water use by 1.25 million acre-feet annually for 2027 and 2028, with Mexico agreeing to cut its own intake by another 250,000 acre-feet. Arizona absorbs the biggest hit at 760,000 acre-feet, followed by California at 440,000 acre-feet and Nevada at 50,000 acre-feet, according to ABC News. States are also being encouraged to voluntarily conserve and store at least 700,000 acre-feet more over the same period. Upstream states Colorado, Utah, Wyoming and New Mexico face no mandated cuts for now.

Reservoirs at historic lows

The cuts come after what PBS NewsHour reported was the worst snowpack on record last winter across the Colorado River Basin. Lake Mead recently dropped to its lowest level since the reservoir began filling nine decades ago, and Lake Powell hit its own record low about a week later — leaving combined storage in the two reservoirs at its lowest point in nearly seventy years. As of August 20, Lake Powell sat just 9 feet above the elevation Reclamation considers critical for continued hydropower generation at Glen Canyon Dam.

Interior Secretary Doug Burgess framed the stakes bluntly in the agency's announcement. "Forty million people, millions of acres of farmland and ranchland, industries that power the American West, and some of our nation's fastest growing metropolitan areas depend on the Colorado River," he said.

"We've been in this 26-year prolonged drought period ... continuing to work together as a whole within the basin is going to be extremely important." — Andrea Travnicek, Interior Department Assistant Secretary for Water and Science

State officials described the deal as a stopgap rather than a fix. Tom Buschatzke, director of Arizona's Department of Water Resources, said the new reductions would "provide substantial stability for folks" as farmers, cities and tribes plan around less water. California's chief Colorado River negotiator, JB Hamby, was more pointed, calling the plan "a bridge, not a permanent solution," according to Nevada Current.

The Interior Department says it will try to keep Lake Powell at or above 3,510 feet — 20 feet above the point at which Glen Canyon Dam could no longer generate hydropower — and has not ruled out deeper cuts over the next decade if drought conditions persist. The current set of interim water-sharing guidelines governing the seven Colorado River Basin states expires in October, and officials say the seven states still have not reached a long-term consensus on how to permanently divide a shrinking river among tens of millions of people.