After years of dwindling water supplies and record-low reservoir levels, an unlikely rescuer has arrived across the American Southwest — heavy rain and flooding that, while destructive in places, is pumping much-needed water back into the region’s parched lakes and underground supplies. The storms are offering a moment of genuine relief in a part of the country that has been locked in a stubborn, long-running megadrought for years.
Flooding that swept through the U.S. Southwest in late October and early November sent powerful walls of water through streambeds that are typically dry or barely flowing. Hundreds of residents were ordered to evacuate, and some communities were temporarily cut off. But according to Martin Hoerling, a climate scientist and hydrologist at the University of Colorado, Boulder, most of that water will ultimately recharge depleted lakes and underground aquifers.
“That’s somewhat of an unexpected boost from Mother Nature,” Hoerling said.
Lake Powell Sees a Dramatic Rise
One of the clearest signs of the storms’ impact is at Lake Powell, the second-largest reservoir in the United States. The lake rose more than 20 feet (6.1 meters) from its mid-September low — a gain that far exceeded what this year’s lackluster snowfall contributed when it melted. Even so, the lake along the Arizona-Utah border remained just over a quarter full as of last week, with 15 of its 17 boat launches still unusable.
Hoerling estimates the floodwaters and additional rainfall could add more than 1.2 million acre-feet of water to the lake in total — enough to supply roughly 4 million average American families for an entire year.
Local Communities Feel the Difference
Towns across the region reported some of the wettest conditions they had seen in decades. In Pagosa Springs, Colorado, roughly 7 inches (about 18 centimeters) of rain fell in October. Before the storms hit, more than 10,000 residents in the town and surrounding areas were living under water restrictions. Restaurants had been asked to serve water only when customers specifically requested it. Those restrictions have since been lifted.
Pagosa Springs Town Manager David Harris acknowledged the storms’ mixed impact.
“While the storm was destructive, I think there is a silver lining,” Harris said. “You’re getting a good start to the winter snowpack in the higher elevations.”
In Flagstaff, Arizona, the results were equally striking. Upper Lake Mary — which captures spring snowmelt and can supply up to 40% of Flagstaff’s water — received more than 3 billion gallons since early October, according to city water production manager Brian Huntzinger. Last weekend’s storms alone dumped the equivalent of more than two full years’ worth of water into the town’s surface water supply.
“It’s just a great, great thing to see,” Huntzinger said. “We might be overflowing at this rate before we see any snow fly.”
In central Arizona, significant floodwaters that trapped residents in their homes flowed into streams feeding the Verde River. That led water managers to release water from two nearly full dams into the normally dry section of the Verde River running through metro Phoenix, said Bo Svoma, the principal meteorologist at the Salt River Project, which oversees reservoirs on both the Salt and Verde rivers.
El Niño May Keep the Relief Coming
The climate pattern known as El Niño has been a driving force behind the intense rainfall, and experts say its effects will persist for several more months. That raises the possibility of continued improvements to water supplies stored in lakes, aquifers, and snowpack across the West.
Still, the region has not emerged from drought. Decisions about water allocations in the Colorado River basin are largely set, and federal managers are unlikely to revise water releases from Lake Powell or other sites until they know how much snow has accumulated — a figure that typically peaks around April. Jack Schmidt, a professor at Utah State University who studies the Colorado River, confirmed that the Bureau of Reclamation will wait for that data before acting.
Reclamation spokesperson Mary Carlson acknowledged the improved conditions but noted that
“considerable uncertainty remains.”
Under an existing federal agreement, California, Nevada and Arizona are required to collectively cut their Colorado River water use by 1.25 million acre-feet per year over the next two years — roughly equivalent to filling more than 600,000 Olympic-sized swimming pools. Even larger cuts remain possible depending on future conditions. Nevada and Arizona are currently challenging that plan in court. Meanwhile, some Arizona cities have agreed to fund early-stage work to expand a dam on the Verde River, allowing more storm runoff to be captured, Svoma said.
Hoerling put the situation plainly:
“We need to figure out how to be resilient in a drier future. And we’re not quite there yet.”
Reporting on Southwest water issues is covered by KNAU and Arizona News. For related coverage, read about how Navajo voters hop tractors, make extraordinary efforts to vote after widespread flooding.
