The Colorado RiverRJ Sangosti/MediaNews Group/The Denver Post/Getty/Grist

This story was originally published by Grist and is reproduced here as part of the Climate Desk collaboration.

There are three main forces driving the conflict on the Colorado River. The first is an outdated legal system that guarantees more water to seven Western states—Arizona, California, Colorado, Nevada, New Mexico, Utah, and Wyoming—than is actually available in the river during most years. The second is the exclusion of Native American tribes from this legal system, which has deprived many tribes of water usage for decades. The third is climate change, which is heating up the western United States and diminishing the winter snowfall and rainwater that feed the river.

The states and tribes within the Colorado River basin have been fighting over the waterway for more than a century, but these three forces have come to a head over the past few years. As a severe drought shriveled the 1,450-mile river in 2022, negotiators from the seven states crisscrossed the country haggling over who should have to cut their water usage, and how much. As the arguments dragged on, the Biden administration chastised states for letting the water levels in the river’s two main reservoirs fall to perilous lows. The Navajo Nation, the largest tribe on the river, went before the Supreme Court to argue for more water access.

These issues are all converging ahead of this fall’s presidential election, which could upend negotiations by ushering in a new Congress and new leadership at the federal Bureau of Reclamation, which controls the river. With the clock running out, two major deals are now taking shape. They could fundamentally alter the way states and tribes use the river, bringing about a fairer and more sustainable era on the waterway—if they don’t fall apart by November.

The first deal would see the states of the river’s so-called Lower Basin commit to lowering their water usage by as much as 20 percent even during wetter years, addressing a decades-old water deficit driven by Arizona and California. There are still questions about how much water the states of the Upper Basin, led by Colorado and Utah, will agree to cut, but state leaders expressed optimism that a final agreement between all seven states will come together in the next few months.

“This is not a problem that is caused by one sector, by one state, or by one basin,” said John Entsminger, the lead river negotiator for Nevada, in a press conference announcing the Lower Basin’s plan to cut water usage. “It is a basin-wide problem and requires a basin-wide solution.”

The second deal would deliver enough new river water to the Navajo Nation to supply tens of thousands of homes, ending a decades-long legal fight on a reservation where many residents rely on deliveries of hauled water.

If both of these deals come to fruition, they would represent a sea change in the management of a river that supplies 40 million people with water. But neither one is guaranteed to come together, and the clock is........

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