JUANA SUMMERS, HOST:

Yesterday six of the seven states that share the Colorado River announced a new agreement to save a lot of water. California was the lone outlier. It does not like the plan. But coming up with a plan is important because if the states keep using water at the present rate, America's two biggest reservoirs could drop so low that they will no longer be able to produce hydroelectric power. Here to explain more is Alex Hager, who covers water for member station KUNC in Northern Colorado. Hey, Alex.

ALEX HAGER, BYLINE: Howdy. Thanks for having me.

SUMMERS: Thanks for being here. Alex, start off by telling us about this deal.

HAGER: Well, the federal government is in a real crunch to keep more water in Lake Mead and Lake Powell. They have both shrunk to record lows after 23 years of drought. So they're considering changes to the amount of water that will be released from those reservoirs for the next couple years. They asked the states for input, and this is how the states responded. Six of them got together and said, we've got an idea for how to find one and a half million acre feet of extra water. That is enough to supply millions of homes every year. So the states said, every year we release a certain amount of water from Lake Mead down to parts of Nevada, California and Arizona. But the amount of water in the lake drops even more from evaporation. So if you just reduce the amount of water being released from Lake Mead by the amount that evaporates, that will help keep water levels from falling further.

SUMMERS: So this plan to me sounds like it's sort of correcting for an accounting issue in many ways. Is it also asking cities or farmers that draw on the Colorado to sacrifice and use less water?

HAGER: No. They came up with this plan because it is so hard to make cuts on the river. It supplies 40 million people and a massive, multibillion-dollar agricultural industry. If you keep more water in the reservoir, that is water that will not flow to someone's tap. So, in effect, it is a cut to people in California and Arizona. But accounting for evaporation is something that a lot of the states can agree on. Right now some users have a legal right to water that doesn't even really exist because it's evaporating before it can flow downstream from the reservoir. Important to remember here - this is not enough water to save the river. It is just a Band-Aid. The federal government says they would need to keep 2 to 4 million acre feet in the reservoirs. This evaporation proposal would only account for 1.5 million. The Southwest is really just trying to hold it together until 2026, when the current rules for the river expire and they can have some big discussions about more permanent changes.

SUMMERS: OK. So if California's going to get less water, I can understand the state's opposition to this plan by the six other states. But does California have a different solution?

HAGER: Yeah. California uses more water from the Colorado River than any other state, and their water rights are some of the oldest. So that means that when there's a shortage, they will be the last in line to lose their water. There's some big farming areas in Southern California that are driving some of this discussion. They're saying, we're legally entitled to this much water, and we intend to use it. The state says it's going to put out its own proposal. They have not yet given any details on that. A lot of the experts I talked to think this standoff is bound for litigation and that the courts are going to decide how it ends.

SUMMERS: So, Alex, what are the next steps in the standoff?

HAGER: Yeah, well, this agreement is not a deal. It is just a proposal for how the feds could proceed. So, you know, we'll see. I talked to a lot of analysts who said the Biden administration will probably adopt parts of this proposal but not all of it. But no matter what happens, the water supply is likely to keep shrinking. Climate change has made the region drier than it's been in 1,800 years. It's getting hotter, and there are a whole lot of reasons that water is really not likely to come back. So the states need to get together and find a way to bring down demand to meet that challenge that's brought on by the change in climate.

SUMMERS: Alex Hager of member station KUNC in Northern Colorado. Thank you.

HAGER: Thank you. Transcript provided by NPR, Copyright NPR.