Officials at the Bureau of Reclamation, the federal agency that manages Colorado River dams, outlined several actions they are considering in the coming months to boost water levels in a rapidly shrinking Lake Powell, which could drop to a record low later this year that would halt hydropower production from Glen Canyon Dam for the first time.
The Colorado River’s second-largest reservoir behind Lake Mead is entering one of the most difficult periods in its six-decade history. The basin is drying due to a warming climate. Powell is just a quarter full, and projected to drop lower this year. Winter has been a dud, with warm temperatures and a historically bad snowpack in the Colorado mountains that feed into the reservoir.
Decisions in the next three months about how much water to release from Powell and how much to hold back will reverberate across the basin, affecting hydropower production, legal obligations, watershed ecology, threatened species, and millions of people who use its water and energy.
“Things are happening in parallel and not in sequence,” said Wayne Pullan, Reclamation’s Upper Colorado Basin regional director. “We’re going to be doing everything all at once.”
Pullan and other Reclamation officials discussed their options during a meeting Wednesday of the Glen Canyon Dam Adaptive Management Work Group, an expert committee that advises on the dam’s ecological impacts.
The number that federal officials are paying attention to is 3,490 feet. Below that point, Glen Canyon Dam cannot produce hydropower. Powell would be too low for water to flow through the power-generating turbines.
A 2024 decision allows Reclamation to “consider all tools that are available” to keep Powell from dropping below 3,500 feet, an elevation that provides a little wiggle room for maintaining hydropower production. Powell today sits at 3,531 feet.
“I think it’s safe for us to assume that unless Mother Nature is uncharacteristically generous, that Lake Powell elevations are going to fluctuate at elevations that we’re not comfortable with,” Pullan said.
The tool from the 2024 decision is Section 6(E), which grants Reclamation the authority to restrict water releases from Powell to as low as 6 million acre-feet. The planned released this year is 7.48 million acre-feet, so the Section 6(E) authority represents a potential 20 percent reduction.
A cut of that magnitude might not be necessary because Reclamation has another tool it can use in tandem.
That option is releasing more water from Flaming Gorge and other smaller reservoirs located higher in the watershed. This is called a DROA release after its authorizing document. Pullan said this action, which states in the lower basin are advocating for, is being discussed and the volume of those releases would be determined in the spring, around April or May.
“It’s important to remember that this is all in flux,” Pullan said. “This cake is being mixed and isn’t baked in any way yet.”
A previous DROA release in 2022-23 moved 463,000 acre-feet from Flaming Gorge into Lake Powell. Flaming Gorge today is 82 percent full, holding almost 3 million acre-feet.
Reclamation’s current projections show Powell dropping below hydropower production level by December, in an average water supply scenario. If snowpack and runoff continue to run below average, then that threshold could be breached, barring interventions, in August.
Katrina Grantz, Reclamation’s deputy regional director, said that in the most probable water supply scenario the agency has the tools to be able to keep Powell above 3,500 feet over the next 12 months. But it is still analyzing how and when to deploy them.
“Reclamation is working on various scenarios of how this could play out,” Grantz said.
There are other considerations in the mix. Powell is the source of cold-water releases to help native fish. The water this year could be record warm. Powell is also the source of high-volume flows to move sediment that rebuilds Grand Canyon beaches and steadier flows that assist aquatic insects. Releases have implications for boating and recreation, too.
The basin’s abysmal hydrology coincides with deep political and legal uncertainty. Current reservoir management guidelines expire at the end of the year, and the seven basin states have not been able to agree on their replacement. Reclamation instead is forging its own path, aiming to finalize a decision this summer.
Reduced releases from Powell could also cause the four upper basin states – Colorado, New Mexico, Utah, and Wyoming – to violate the Colorado River Compact, which requires a certain volume of water to move downstream. This requirement and its legal ramifications are not clear and could be litigated.
It all amounts to an unsettling time for those working in the basin.
“We have to work with the resources we have,” Pullan said. “Wishing will not make things so.”
This article first appeared on Circle of Blue and is republished here under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
