Record-low snowpack in the Upper Colorado River Basin and the prospect of near-record-low runoff this spring into Lake Powell are likely to ratchet up conflicts in the seven-state negotiations over the river’s future, a longtime water expert says.
This past week, the federal Colorado River Basin Forecast Center reported that snowpack in the Upper Basin was 47% of average snowpack figures from 1991 through 2020. Moreover, snowpack is at the lowest levels seen in records at various weather stations across the Upper Basin dating back 30 to 45 years.
In addition, the runoff forecast of 38% of the average for the period April through July represents a drastic decline from the forecast of 63% of average runoff projected just a month ago. The tumbling forecast stems directly from unusually warm, dry weather in the Upper Basin in December and January, the federal forecasters say.
If the 38% forecast proves accurate into the spring and early summer, that will be the fifth-lowest spring-summer runoff into Lake Powell on record, said Brenda Alcorn, a senior hydrologist for the forecast center.
The low runoff figure could well push the river basin into the legal danger zone of failing to comply with the 1922 Colorado River Compact, said Eric Kuhn, an outside water researcher who has tracked the river's declining flows for many years now. That's because if runoff into Powell is low, releases downstream from the Upper Basin (Colorado, Utah, New Mexico and Wyoming) to the Lower Basin (Arizona, California and Nevada) would likely be reduced, he said.
Low runoff could push the 10-year average of water releases from Lake Powell to Lake Mead below the federally mandated minimum of 82.5 million acre-feet a year, said Kuhn.
If the runoff falls as low as now predicted, the U.S. Bureau of Reclamation will be under increasing pressure to reduce releases of river water from Powell to Mead to keep Powell from falling below 3,500 feet elevation, he said. The Glen Canyon Dam adjoining Lake Powell can’t generate electricity if the lake drops below 3,490 feet, and bureau officials want to keep the lake at 3,500 feet elevation, at least, as a buffer.
Lake Mead would, in turn, get less water if that happens, lowering its levels.
If the 10-year flow falls below that 82.5 million acre-foot figure — a number Kuhn and other experts call a “tripwire” — that would increase the chances of litigation by Arizona, California and Nevada against the Upper Basin states, Kuhn said.
Most likely, litigation would allege the Upper Basin states are failing to meet legal obligations under the 1922 Colorado River Compact to deliver a minimum amount of water to the Lower Basin states over a decade, he said.
Shown here dramatically free of ice on Jan. 10, 2026, the Gunnison River is a major tributary to the Colorado River. Unusually warm weather lingered through late autumn and into early winter throughout central Colorado, raising concerns over snowpack levels and water resources for Western states including Arizona.
As river flows get lower, “the stakes are higher,” said Kuhn, co-author of a book about the compact. And if the states fail in their negotiations to come up with a plan good enough to get the Lower Basin states to waive their rights to sue over compact compliance, "there are real consequences."
“With litigation comes more power for the (U.S. Interior) secretary, and more uncertainty about how you operate the river during litigation,” Kuhn continued. “There’s just lots of questions.”
The issue of Colorado River Compact compliance has already been a major sticking point in the deadlocked negotiations between the two basins as they attempt to work out a new set of guidelines to manage the river’s reservoirs.
The current guidelines expire later this year. The Interior Department has set a Feb. 14 deadline for the states to reach agreement, but the negotiations have shown little signs of progress until very recently.
Throughout the seven-state talks, the Upper Basin states have said they want the Lower Basin to commit to waiving any future legal claims over compact compliance. The Lower Basin states have refused to do that unless the Upper Basin states commit to reducing their use of river water.
The Upper basin states have said "no" to that, saying their cities and farms use far less water than those in the Lower Basin.
Asked Friday about the low runoff forecast, Arizona Department of Water Resources Director Tom Buschatzke said only, "The Basin States are aware of the hydrological forecast and it is being discussed as part of the negotiations."
A spokeswoman for Becky Mitchell, Colorado's Colorado River commissioner and lead negotiator, didn't respond to an email from the Star seeking comment on the runoff forecast.
Even before the latest forecasts, Arizona water officials were already warning that compact violations were looming over the horizon.
“It looks like we may breach the compact in 2026 and almost certainly in 2027," Central Arizona Project General Manager Brenda Burman, whose agency delivers drinking water to Tucson from the Colorado River via canal, said at a Feb. 2 meeting of various Arizona water officials. "That’s sobering news," she added. "That’s something that hasn’t happened before. Our Upper Basin neighbors always met that in the past.”
Several speakers at that meeting from cities and state agencies also blasted the U.S. Bureau of Reclamation’s new draft environmental impact statement on the Colorado River, saying it fails to address the issue of compact compliance.
The Upper Basin states have denied, however, that they would be violating the compact if water releases fall below the minimums cited by Kuhn and Lower Basin officials. They say climate change — not their water use — has depleted the river’s flows and that the compact sets a “non-depletion obligation,” not an actual delivery obligation, for the Upper Basin to fulfill.
They haven’t accepted any legal responsibility to deliver the full 82.5 million acre-feet over 10 years because 7.5 million acre-feet of that represents the U.S. obligation to deliver water to Mexico under a 1944 treaty. The Upper Basin states say they aren’t bound by that obligation.
Low runoff will also likely increase pressure on Reclamation to release more water from upstream reservoirs such as Flaming Gorge in Wyoming and Blue Mesa in Colorado into Lake Powell to prop Powell up further, Kuhn said.
That has also been a bone of contention between the Upper and Lower Basin states. The Lower Basin wants more water released from upstream reservoirs to boost Powell, while the Upper Basin wants to keep as much water in the Upper Basin reservoirs as possible.
