Six western states that rely on the Colorado River for their water supply have agreed to drastically cut water use in response to the federal government’s call for a concerted plan to conserve water amid looming, and possibly catastrophic, critical shortages. A seventh state, California, remains at odds with the plan reached by Arizona, Colorado, Nevada, New Mexico, Utah and Wyoming, suggesting major cities like Phoenix and Las Vegas should be cut off from the water supply in order to protect California’s agriculture. Two decades of climate change-fueled drought have brought reservoirs at Lake Powell and Lake Mead dangerously close to what’s known as “dead pool,” when water level becomes so low it no longer flows through the dams. This is David Hayes, a Stanford professor and former climate adviser to President Biden.

David Hayes: “The crisis is incredibly severe. In fact, the Interior Department is faced with the potential for not being able to make deliveries of water out of the Hoover Dam to the city of Las Vegas or to the state of California, period. The water levels behind the dams have become so low that they may not be able to make deliveries. And that’s the worst of all possible worlds.”