SACHA PFEIFFER, HOST:
Water levels at the nation's two largest reservoirs are at record lows. Lake Powell and Lake Mead hold water from the Colorado River. The reservoirs drying up is a major threat to the water supply for tens of millions of people across the West. From member station KJZZ, Alex Hager reports.
ALEX HAGER, BYLINE: Standing on a red rock cliff overlooking Lake Powell on the Arizona-Utah border, the signs of its decline are visible. Even with the reservoir less than a quarter full, speedboats are still cruising across the surface, but they're doing it under about 180 feet of towering white bathtub rings on the canyon wall. They're a sign of how high the water used to be, and how the Colorado River, which fills this reservoir, is in trouble.
ERIC BALKEN: The last time Lake Powell reservoir was this low, Neil Armstrong had not set foot on the moon yet, so this really is a historic moment.
HAGER: Eric Balken is director of the Environmental nonprofit Glen Canyon Institute. Balken says Powell looks like this because of drought, climate change and steady demand from people.
BALKEN: We have to start thinking about how to manage this system when all of the reservoirs are at critically low levels.
HAGER: Lake Mead, downstream near Las Vegas, also hit a record low last week. The federal government is scrambling to put out a new plan for managing the Colorado River after the states that use it couldn't agree on how to bring down demand. They're in a pinch because of what would happen if it drops much lower. Below the massive dam that holds back Lake Powell, the Colorado River flows downstream, and long power lines stretch up to the desert above.
If the lake drops just 30 feet lower, water can't flow through the turbines that generate electricity inside the dam. Much lower than that, it might not be able to pass water through at all, threatening the supply for cities like Phoenix and San Diego, plus a massive farming industry. At the base of the iconic dam, Sara Porterfield, with the conservation group Trout Unlimited, says it's a time of reckoning.
SARA PORTERFIELD: What do we do with this incredibly important piece of infrastructure that is important, not just for the power it produces, the water storage capacity but also is culturally important?
HAGER: Climate scientists say Powell and other Colorado River reservoirs are unlikely to fill again anytime soon. Climate change and drought mean less coming in, and policymakers need to adjust how much people take out.
For NPR News, I'm Alex Hager in Arizona.
(SOUNDBITE OF SLAPES' "MALUMA") 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.