Will another snowy winter boost the Colorado River? It hasn't happened in this century
Six months after three southwestern states struck a deal to keep more Colorado River water behind drought-shrunken Hoover Dam, those states face the first test of whether it’s enough to keep the region out of crisis.
The arrival of the winter snow season, which sustains the river and last year bailed out water users facing critically low reservoirs, brings new questions for water managers: Will El Niño conditions in the Pacific Ocean produce a wet winter in the Southwest and parts of the Rockies? And could a second straight wet winter wallop the region with above-average snowfall and again forestall more drastic conservation measures?
Jack Schmidt’s unofficial daily weather report during a visit to the ski town of Park City, Utah, on Wednesday morning revealed his skepticism. “It’s going to be 60,” the Center for Colorado River Studies program director and former head of the Grand Canyon Monitoring and Research Center noted.
That’s an inauspicious omen for a ski season that was set to start there on Friday. The temperature actually climbed only to 56 that day, but that was 29 degrees warmer than the same date last year.
Arizona had a wet winter last year: Will El Niño bring more of the same?
It’s only one point on a map, one day on the calendar. To Schmidt, though, it demonstrates how fickle the West’s climate has become, and how little room there is for complacency in shoring up the reservoirs that water a farming empire, 40 million people and, to name just one treasured nature preserve, the Grand Canyon.
Schmidt isn’t predicting the weather, but he has crunched the numbers on the drought or aridification patterns that plunged the Colorado into peril over the last 23 years and they aren’t pretty.
Last winter was the second-wettest of that time, behind 2011. There have been a handful of high-snow, high-flow years in that span, but none was followed immediately by another. Each such winter has provided no more than a two-year arrest in the system’s downward slide. Without another one this winter, Schmidt said, the region will be back in crisis despite the states’ agreed cutbacks.
And history shows that those who hope another wet winter will forestall tough choices risk disappointment.
“We might get that free pass,” he allowed, “but it’s certainly not a lock.”
Water issues: Feds will pay Arizona farmers and tribes $64M to use less water from the Colorado River
Why experts don't see favorable trends
Already, the region has used about a fifth of last winter’s windfall, Schmidt said. That’s enough to set water storage back where it was in June of 2021, a time that was better than last year, but still an impending disaster that sent water managers scrambling and forced central Arizona farmers to prepare for a cut off.
Like Schmidt, federal forecasters and some water system managers are tamping down optimism for this El Niño, the term for years in which warm ocean surface temperatures in the equatorial Pacific tend to alter the jet stream and precipitation patterns.
“You hear people say, ‘Oh, well, it’s an El Niño year, (so) we’ve got nothing to worry about,’” Schmidt said. “El Niño is not a great signal or a great predictor of anything. We certainly aren’t off to the gangbuster start we had last year.”
National Weather Service meteorologists reinforced the uncertainty in a Phoenix briefing this week. Their predictions for northern Arizona’s high country, which saw big snows in tandem with the Rockies last winter, amount to essentially even odds.
This year’s El Niño is a strong one, meaning ocean temperatures are warm enough to clearly indicate it’s underway, according to Ken Drozd, a meteorologist with the Weather Service’s Tucson office.
Scanning moderate to strong El Niños in recent decades, he found that about half bring wet winters to the state, meaning snow in the north. About 30% are drier than normal, including the winter of 2015-2016. About 20% are near normal. At present, the Weather Service’s Climate Prediction Center gives roughly even odds to all three possibilities: wet, dry and normal.
“They really don’t see any favorable trend,” Drozd said.
At both the Central Arizona Project, which delivers Colorado River water to Phoenix and beyond, and Salt River Project, which manages water that flows from the Arizona high country, officials told The Arizona Republic they were likewise unclear about this El Niño's promise.
The U.S. Interior Department and its dam managers at the Bureau of Reclamation this fall have publicized big investments they’ve made in short-term conservation and long-term efficiency programs meant to keep Lakes Powell and Mead from dropping to critical levels over the next three years. That’s the timeframe in which the department must negotiate or, if negotiations fail, impose a new set of rules for cutting allocations to seven states if drought returns and pushes water toward the point where it can’t generate power or consistently flow past dams.
States are using less water than they have in decades
In Phoenix this month, Reclamation Commissioner Camille Calimlim Touton joined Arizona Gov. Katie Hobbs in celebrating the latest seven of 18 deals the federal government has signed with cities, tribes and irrigators in the state to keep nearly 1 million acre-feet of water in Lake Mead through 2025. Taken together, that’s more than a third of what the state once diverted from the Colorado in a given year. The cost to federal taxpayers is $378 million.
An acre-foot is roughly 326,000 gallons. Each acre-foot is enough to supply two or three Arizona households, though most of the water is used on farms.
Atop other cutbacks imposed or offered over the last decade, Arizona Water Resources Director Tom Buschatzke said, the state and its neighbors in Nevada and California are using less Colorado River water than they have since 1984.
Lake Powell and Lake Mead, the nation’s two largest dam-controlled reservoirs, were full around the turn of the 21st century but dropped to about a quarter of capacity before last winter’s snow melted and ran down the river and into them. They’re currently hovering around one-third full.
It was a timely bump as states negotiated over how to get through the next few years, but Schmidt’s analysis shows that there have never been two years in a row in the century when water users used less than what the river added back.
Before snow fell last year, Interior and Reclamation officials warned states that they must find at least 2 million acre-feet a year in new cuts. Instead, buoyed by the big winter, the Lower Basin states of Arizona, California and Nevada offered 1 million a year for three years. Reclamation enthusiastically embraced that deal this fall, calling it a “historic consensus-based secured by the Biden-Harris administration in partnership with states.”
While it didn’t meet the government’s original demand, Buschatzke said that, in combination with the strong meltwater runoff this year, it did what the government required: It stabilized the river system through the upcoming negotiations for what happens after 2026.
“It was the right step at the right time,” he told The Republic.
'We sure do hope it snows this winter'
The Bureau of Reclamation this week released its latest 24-month study, a monthly projection for the next two years of reservoir levels. It shows the most likely outcome is that neither of the big reservoirs will dip to critical levels in that time.
“So I would say that enough has been done for now to avert the crisis, and I give credit to the states (especially Arizona and California) for coming up with an agreement that can reasonably be expected to keep the system stable through 2026,” Arizona State University Kyl Center for Water Policy Director Sarah Porter told The Republic in an email. “Without these measures, negotiations over the 2026 guidelines would be much more difficult.”
The federal funding, secured in the Inflation Reduction Act for use throughout the watershed, was important, she said. “Continued funding is probably key.”
In Schmidt’s view, the deal clawing back 3 million acre-feet over three years is helpful, but not enough.
“What they’re really saying is the 3 (million) was the best we could get,” he said. “But what they’re also saying is we sure do hope it snows this winter.”
He isn't giving the Upper Basin states a free pass. So far, the Lower Basin users in Arizona, California and Nevada have borne the brunt of reductions because they use most of the water. Everyone along the river, including the Rocky Mountain states, needs to pitch in more, Schmidt said.
If it doesn’t snow big, he expects a repeat of every other wet year since 2000. In each case, the gains in reservoir storage were gone within two years.
“We’re not making any monumental strides” in conservation, Schmidt said. “If we don’t have a good winter, then that’s when we go off the cliff again.”
Brandon Loomis covers environmental and climate issues for The Arizona Republic and azcentral.com. Reach him at brandon.loomis@arizonarepublic.com or follow him on X, formerly known as Twitter, @brandonloomis.
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This article originally appeared on Arizona Republic: As winter snows loom, critical season for Colorado River looms
