ROB SCHMITZ, HOST:
When it comes to water, what happens in Colorado does not stay in Colorado. Over the last 25 years, water levels in the Colorado River have been steadily dropping, causing crucial reservoirs across the West to dry up, impacting more than 40 million people in seven U.S. states, dozens of tribal communities and Mexico.
Yesterday, the federal government offered a solution. It proposed a 10-year framework to reallocate access to water from the Colorado River among these states. This comes at a time when states like Colorado itself are going through yet another historic drought. Joining us now is Russ Schumacher. He's a professor of atmospheric science at Colorado State University, and he advises the state on climate matters. Welcome, Russ.
RUSS SCHUMACHER: Thanks for having me.
SCHMITZ: So, Russ, tell us a little more about this plan.
SCHUMACHER: In the West with water in the Colorado River Basin, there's a somewhat complicated compact that was established a little over 100 years ago about who gets to use how much water in the Colorado River.
SCHMITZ: OK.
SCHUMACHER: It's divided between the Upper Basin states - which are Colorado, Wyoming, Utah, New Mexico - and the Lower Basin states - California, Arizona, Nevada. And so essentially the Upper Basin states and the Lower Basin states get an equal allocation of water from the Colorado River Basin, but there's not as much water in the system now as there was in the 1920s when that compact was established.
There's more demand for water because a lot more people are living in the West, and so it's led to this complicated situation of negotiations between the Upper Basin and Lower Basin states and the federal government about what to do with the declining water supplies. And the plan that was released by the federal government indicates that the Lower Basin states especially would be subject to reductions in use of Colorado River water.
SCHMITZ: What will that mean for those states? - for the states in the lower part of the river. These are states like California, Arizona, Nevada. These are states with huge populations, obviously.
SCHUMACHER: Yeah. And what a lot of that Colorado River water supports is agriculture in those states, and so it'll mean that most likely in dry years, those states will have to reduce their use of the Colorado River water, whereas the Upper Basin states - the cutbacks will be more voluntary. The majority of the reductions or the conservation requirements will be on the Lower Basin states.
SCHMITZ: And how have these Lower Basin states reacted?
SCHUMACHER: The negotiations, or some of the tension over the years, have been that generally the Lower Basin states have been using more of their allocation, whereas the Upper Basin states haven't. But at the same time, the agricultural production in those Lower Basin states is crucially important, big populations, and this is where a lot of the tension comes around.
The supply is up where we are in Colorado, in our mountains. So the snow that falls in our mountains in the winter is the source of that water that goes into the Colorado River as it melts out in the spring and summer. And then it goes into those reservoirs and then gets released for use further downstream.
So when we have bad snow years like this one, there's less water on the supply side. The demand tends to go up in the dry years, and we've had a lot more dry years than wet years in the last couple of decades, and so that's brought us to the challenges that we have here today.
SCHMITZ: Now, Russ, I'm asking you a lot of questions about this new federal plan, but you are a climatologist, and I wanted to ask you about this drought that the Southwest region of the United States has been experiencing for so many years. Why has it persisted?
SCHUMACHER: Yeah, we've had years with not very much snow in the southwest or in the mountains. This past winter was, in Colorado, the worst winter for that mountain snow that we've had since snowpack has been measured in our mountains. And it's also been very warm. We had record-setting months for warmth in December and February and March, and now we've gone into a quite hot and dry summer as well, and so we've had fast-growing wildfires. We've gotten some relief with the monsoon setting in in July and getting those afternoon thunderstorms that have helped with the fire risk, but then that's led to flash floods.
I think this year, going back to last fall and into this year, has been one of the worst that we've had, but we've had a lot of these bad years with not very many of those bountiful years in between. And so the supply of water that comes from that snow that falls in the mountains has been on the decline. And then, of course, the demand for water in the southwestern U.S. has continued to go up, and that's left the Colorado River Basin as well as some of the other river basins in the West in the rough position that we're in right now.
SCHMITZ: Yeah, I was just in Colorado, actually. I was just in southwestern Colorado, and I was within a mile of a wildfire that was sort of on its tail end, and then suddenly - you mentioned the monsoons - it started raining quite a bit, and there was actually flash flooding in the area. You know, this summer in particular has been among the driest in the region's history. What do you think that spells out for the future of Colorado?
SCHUMACHER: Yeah, you know, we're cautiously hopeful that as we get into the fall, maybe into next winter, we have this probable super El Nino that's been discussed quite a bit that's now in place and expected to strengthen. El Nino leads to bad weather and climate outcomes in a lot of the world, but in the western U.S., especially in the Southwest, it does tend to be wetter during fall and winter and spring during El Nino. So there's a bit of cautious optimism that we'll at least get some relief from the drought as we get later into the fall and winter.
But in the near term, we've got another big heat wave on the way. And we can't count on - there's no guarantees with El Nino that it's going to provide a lot of relief. And then in the longer, longer term, we have climate change. We have warming that's especially been affecting the southwestern U.S. When droughts happen - of course, droughts are natural part of the weather and climate in this part of the country, but they're getting made worse as we warm up because warmer air is thirstier for water, and so the atmosphere is trying to just pull more of that water out of the landscape, and so that - you know, a hot and dry drought is worse than just being dry. And we're, I think, really seeing the effects of that this year.
SCHMITZ: That's Russ Schumacher. He's a professor of atmospheric science at Colorado State University. Russ, thanks so much.
SCHUMACHER: Thank you.
(SOUNDBITE OF MUSIC) Transcript provided by NPR, Copyright NPR.
NPR transcripts are created on a rush deadline by an NPR contractor. This text may not be in its final form and may be updated or revised in the future. Accuracy and availability may vary. The authoritative record of NPR’s programming is the audio record.
