IRA FLATOW: The Southwest has been dealing with a water crisis for years. This is really nothing new, is it? As the amount of water available goes down, especially in the Colorado River, states need to figure out how to reduce the amount of water they use. And really, there’s no easy answer.

About a week and a half ago, we got one step closer to a solution. Arizona, California, and Nevada presented a plan that would voluntarily cut their water use. This comes after a lot of pressure from the federal government, which would have imposed its own plan if states couldn’t work it out on their own.

So what’s it all about? Here to tell us are my guests Dr. Sharon Megdal, director of the Water Resources Research Center at the University of Arizona, in Tucson; Luke Runyon, managing editor and reporter for KUNC, based in Grand Junction, Colorado.

Welcome back, both of you, to Science Friday.

SHARON MEGDAL: It’s my pleasure.

LUKE RUNYON: Yeah, thanks for having us, Ira.

IRA FLATOW: Nice to have you both.

OK, Luke, can you break it down for us? What exactly is in this proposal?

LUKE RUNYON: So this is a proposal that’s coming from the three states that make up the lower basin of the Colorado River. And that’s Arizona, California, and Nevada. And what they’re putting forward is 3 million acre feet in conservation.

And for those people not totally drenched in the water world, an acre foot is about what it takes to supply two average households for their annual water use in the Southwest. And in exchange for coming up with this conservation goal, the states are going to be receiving more than $1 billion in federal funding from the Inflation Reduction Act. And that was this huge investment in climate change mitigation and adaptation from Congress and the federal government last year.

So this is a huge investment in these lower basin states in order to meet this conservation goal.

IRA FLATOW: Sharon, as Luke said, this is going to impact the lower basin states. So Arizona, California, and Nevada. What’s this going to look like then for those states?

SHARON MEGDAL: Well, we’ve already had a partial glimpse of what it will look like because we’ve been reducing water use based on lower Colorado River water deliveries for a few years now. And what this is going to mean is less water delivery to some of the users, including agricultural users, who use the bulk of the water, but also to some cities, to some tribal nations.

The idea is for less water to be taken from the river so it can remain in the system, particularly in Lake Mead, which is the large storage reservoir behind Hoover Dam, so that the system avoids crashing. That has been the big threat that we’ve faced– is that nature hasn’t been producing enough water and the storage in the Lake has gone down and down. Fortunately, we had a very good winter, which took off some of the pressure. But what it’s going to look like is less water use.

But the key word is people have agreed to this based on the compensation the federal government will offer. But this is not necessarily the permanent solution. This is just really buying us time for the next three years. Because there’s a big, big renegotiation of how to deal with less water on the River that has to get underway and has to be in place by 2026.

So this is breathing room. Some people are calling it a Band-Aid. But this is not the long-term solution to less water in the Colorado River.

IRA FLATOW: Luke, Sharon was talking about a wetter than normal year for several Western states. Does that have anything to do with why we’re seeing this now?

LUKE RUNYON: That’s a huge reason why this agreement came together. A lot of the discussion last summer was about the even more conservation that was needed on the Colorado River in order to stabilize the river system. And this huge amount of snow pummeled the Rocky Mountains over this past winter. And what that does is it alleviates the pressure on the negotiators, the policymakers, who are sitting down at the negotiating table coming up with these agreements.

The sense of urgency among all of those people decreased as that snow started piling up. You’ve just got a tremendous amount of new water that’s entering the Colorado River system this year. But that’s a short-term boost for some of these reservoirs. What we know in the Southwest is that the region is warming and drying. And so you can still have these really wet years, but the trend is towards warming and drying.

IRA FLATOW: And how will this plan, Luke, affect the upper basin states? At all?

LUKE RUNYON: Not yet. This agreement is really coming from the three lower basin states. And this was a negotiating tactic on behalf of the four upper basin states– Colorado, Utah, Wyoming, and New Mexico– who basically said the bulk of the volume of water that’s used in the Colorado River Basin is in the lower basin states. They’re the ones who need to be putting forward this conservation right now. And it’s not our turn to be putting forward these hard conservation agreements just yet.

IRA FLATOW: Sharon, I mentioned at the top that if the states hadn’t come up with a plan, the federal government would come up with one of its own. Do you think that was a scary thing for the states?

SHARON MEGDAL: Absolutely. That is something the states always want to avoid. And actually, the federal government wants to avoid that as well. Because the concern is that if the federal government imposes its solution on the states, it is very likely to make one or more of the states or parties within the states unhappy. And then people go to the courtroom and things get delayed or all mixed up in the courts. Which don’t produce any more water– just delay implementation of solutions.

IRA FLATOW: Yeah.

SHARON MEGDAL: And so everybody wants to avoid that. But what was happening– and this is why the breakthrough that was announced a week and a half or so ago was so important– was that you had Arizona and California, the two biggest users of Colorado River water in the lower basin, not in agreement about sizes of cuts and distribution of the cuts. And the federal government was not on board. But yet, as I’ve heard– and maybe Luke has heard– through some almost sleepless nights and negotiation over the weekend, they came to agreement.

And the upper basin signed on as well. Because the upper basin is always watching what the lower basin states are doing to make sure that they’re not adversely affected. And they came to agreement. Which I think was just a big sigh of relief. And the federal government indicated that it is pulling back this process– it’s suspending the process that was underway– looking at the two alternatives they had put out, in addition to the do-nothing alternative. And everybody agreed, the do-nothing alternative is not an alternative.

And now they’re going to reissue their environmental impact statement for review with this new agreement as part of it. And so I don’t know how long that will take. But I think everybody is breathing a sigh of relief at least for the short run.

IRA FLATOW: Right. Luke, what comes next? How does this actually work? I mean, do they actually stop pulling water out and people say, well, I can’t use as much water? Do you need the cooperation of the public on this?

LUKE RUNYON: Well, some of the states that have signed on to this agreement say that they’re ready to start implementing this right away. And some of this gets down into the weeds of contracting with irrigation districts, large agricultural users in the lower basin. But yes, some of these cuts are going to start being implemented right away. They’re not necessarily waiting for this federal review process to finish. They say, we’ve got this agreement in place. We’re ready to start taking less water from the Colorado River.

But really what comes next is this breathing room that Sharon mentioned. This is really the states gearing up for an even harder set of negotiations that are going to be taking place over the next three years to come up with a new set of managing guidelines for the Colorado River.

Those were first agreed to in 2007. They expire at the end of 2026. And that’s really where the extremely hard conversations are going to be had.

IRA FLATOW: Sharon, if this proposal does move forward and it’s successful, will it actually be enough to slow down how quickly the Colorado River is drying up?

SHARON MEGDAL: It won’t slow down how quickly nature has the Colorado River drying up. It will slow down the implications of that by preventing the system from going so low in terms of storage that you can’t produce hydropower, that you are even risking water getting past the dams to be delivered downstream of Hoover Dam.

And so nature is nature. And even with this new agreement that we expect can get us through the next three years, that’s not guaranteed. If we follow this very wet winter with multiple very dry winters, this agreement may have to be adjusted and more cutbacks put in place.

IRA FLATOW: Wow. That is an interesting case. We will have to follow along with you. Thank you both for taking time to be with us today.

SHARON MEGDAL: Thank you for having me.

LUKE RUNYON: Yeah, thank you, Ira.

IRA FLATOW: Dr. Sharon Megdal, director of the Water Resources Research Center. That’s at the University of Arizona, in Tucson. Luke Runyon, managing editor and reporter for KUNC, based in Grand Junction, Colorado.

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