Enough water likely will fill the Colorado River’s two major reservoirs for the next three years to stave off a hydroelectric power failure and other worst-case scenarios, federal officials said Wednesday.
The declaration is based on unexpectedly heavy snowfall in the Rocky Mountains last winter and states’ commitments to reduce water use. Analysts with the U.S. Bureau of Reclamation relied on promised cuts by water users and data collected in June to redo forecasts for Lake Mead and Lake Powell, finding slim chances that water levels in the two reservoirs would fall beneath critical elevations before the end of 2026.
Water levels at such low levels would threaten the dams’ abilities to generate power and move water downstream.
The chances that water levels will fall below critical elevations before 2027 are now 8% at Lake Powell and 4% at Lake Mead, according to the new analysis. Previous estimates, based on September 2022 data and an assumption that nothing would change in the management of the reservoirs, had found a 57% chance of critically low elevations at Lake Powell and 52% at Lake Mead.
With the improved forecasts, the federal government appears poised to move forward with a plan by the seven states in the Colorado River Basin to reduce use for the next three years. Earlier this year, federal officials proposed forcibly cutting the amount of water sent downstream to the Lower Basin if the states could not find a compromise on reducing use.
On Wednesday, the officials said they had ruled out those forced cuts.
The analysis released Wednesday, as part of the latest draft of a federally required environmental impact statement, will shape how the reservoirs are operated through 2026. That is when current operational guidelines created in 2007 will expire.
Long-term negotiations continue for how the river should be managed after 2026.
“Throughout the past year, our partners in the seven Basin states have demonstrated leadership and unity of purpose in helping achieve the substantial water conservation necessary to sustain the Colorado River System through 2026,” Deputy Interior Secretary Tommy Beaudreau said in a news release. “Thanks to their efforts and historic funding from President Biden’s Investing in America agenda, we have staved off the immediate possibility of the system’s reservoirs from falling to critically low elevations that would threaten water deliveries and power production.”
The Bureau of Reclamation now will undertake a more thorough analysis of the states’ plan. The plan, created by the three Lower Basin states — California, Arizona and Nevada — would reduce water use by those states by 3 million acre-feet over the next three years. Most of that reduced use would be achieved through projects paid for by federal money from the Inflation Reduction Act, including conservation projects in Tucson and Phoenix.
The four Upper Basin states — Colorado, New Mexico, Wyoming and Utah — signed onto the plan this spring.
Colorado’s top negotiator for the river said in a news release Wednesday that she and her team were reviewing the revised federal analysis and considering whether the analysis can “provide meaningful and enforceable reductions in use to address near-term challenges facing the Colorado River System.”
“If there’s a lesson to be learned from the last few years, it is that we must live within the means of the river if we hope to sustain it,” said Becky Mitchell, the state’s Colorado River commissioner.
Pursuing the states’ plan instead of implementing forced cuts was a good choice, said Taylor Hawes, the Colorado River program director for The Nature Conservancy. The decision provides certainty that’s needed in the basin, Hawes said, while minimizing the litigation that likely would have followed any federally imposed mandatory cuts. That litigation could’ve held up any progress on the issue for years, she said.
“That is not an option right now,” Hawes said.
Long-term drought and overuse continue to dry the Colorado River, which provides water to 40 million people in the West, in the long term. The last two decades have been the driest period on the river in more than a century and one of the driest periods in the last 1,200 years, according to the Bureau of Reclamation.
Since the current river guidelines were adopted in 2007, river authorities repeatedly have had to make changes and additions to the guidelines to account for ongoing drought conditions.
Despite the heavy snowpack from last winter, Lake Powell remains only 37% full and Lake Mead sits at 34% capacity.
“Absent a meaningful and unexpected change in hydrologic conditions and trends, water use patterns, or both, Colorado River reservoirs will continue to decline to critically low elevations, threatening essential water supplies across seven states in the United States and two states in Mexico,” the new draft supplemental environmental impact statement says.
It’s hard to say what would’ve happened had the Rocky Mountains not experienced a heavy snowpack last winter, said Rhett Larson, a water law professor at Arizona State University.
“Good hydrology and federal money can’t be what we rely on every decade to buy time,” he said.
Moving closer to finalizing the short-term plan for the river allows attention to focus on long-term planning, Hawes said. The good water year allowed people to breathe a sigh of relief, she said.
“We’ll take the breather, but we recognize it’s just that — a breather,” she said.