Colorado scientist Brad Udall spent hours digging — with frustration — through the federal government’s 700-page proposal for managing key dams and reservoirs in the Colorado River Basin over the next three years.
“I just wish they would really simply say, ‘And here’s how the system would perform under these really bad years we’ve seen over the last 23 (years),’” said Udall, senior water and climate research scientist at Colorado State University. “If they would do that, you would see that this system crashes.”
Udall is one of many water experts and officials across the West who are carefully analyzing the federal proposal released Oct. 25 by the Bureau of Reclamation. The draft document focuses on how water is stored in and released from two key reservoirs: Lake Powell and Lake Mead. It says basin conditions have improved and outlines options to either maintain the status quo or to conserve 3 million acre-feet of water in the Lower Basin, which includes Arizona, California and Nevada.
Water officials and experts say the proposed savings are “a start,” and Reclamation’s option to conserve water would be a “prudent” choice. Regardless, this winter’s precipitation, officials say, will be key in whether the basin’s stored water supply can skate through 2026 without issue — or whether 40 million water users could be hit with another water supply crisis. Udall had some concerns, mainly that the federal analysis could be too optimistic.
“The biggest takeaway is that the wet year in 2023 gave us some breathing room,” Udall said. “But I will say that based on my own knowledge of how this system operates … we’re still on the edge.”
The Bureau of Reclamation started its near-term planning process in 2022 and released its first draft proposal in April. People have until Dec. 11 to submit comments in response to the revised proposal, after which the Bureau of Reclamation will release its final plan.
The draft analysis provides more details about how exactly the Lower Basin would cut water use by 3 million acre-feet — more than three times the amount of water in Blue Mesa Reservoir, Colorado’s largest body of water — over three years.
Reclamation dubbed this plan as its proposed action, but it could still choose to take no action and maintain current dam operations.
“I don’t think anybody believes that plan, honestly,” said Jennifer Gimbel, senior water policy scholar at Colorado State University. “I think they’re all headed toward the Lower Basin agreement.”
Colorado is not committing to cutting its water use as part of the Lower Basin plan, but Colorado River Commissioner Becky Mitchell urged Coloradans to stay engaged in the process.
“We need to hold not only the Lower Basin accountable, the federal government accountable, but ourselves accountable to operating the system in a way that’s good for all,” said Mitchell, the state’s top negotiator for Colorado River Basin issues.
What’s the Lower Basin plan?
Under the proposed plan, Lower Basin water users would conserve 1.5 million acre-feet of water in 2024, and then conserve another 1.5 million acre-feet over the next two years. One acre-foot of water supports about two families of four to five people for one year, according to the 2023 Colorado Water Plan.
The federal government plans to compensate water users for up to 2.3 million acre-feet of conserved water. After that, farmers, ranchers and other water users would either save water without compensation, or they’d have to look to local and state entities for funding.
“It’s a big deal to have main stem water users in Arizona and main stem water users in California — essentially they’re agricultural water users — participate. Even if it’s compensated, it’s a big deal,” said Sarah Porter, director of the Kyl Center for Water Policy at Arizona State University. “In that respect, there may be a kind of shifting of gears. That’s notable.”
Key players in the Lower Basin would all cut water use. The Southern Nevada Water Authority would be responsible for all of Nevada’s savings, promising to conserve 285,000 acre-feet, according to the federal proposal.
California will reduce its use by 1.6 million acre-feet, of which an estimated 800,000 acre-feet will come from the Imperial Irrigation District, where farmers grow about 80% of the nation’s winter vegetables.
In Arizona, cities, tribes and irrigation districts will contribute about 1.2 million acre-feet of water savings. Both the Gila River Indian Community and the subcontractors on the Central Arizona Project will contribute about 402,000 acre-feet, according to the federal proposal.
“It’s looking at the conditions we have now, assessing the risk — which includes a possibility of a very dry winter — this seems like a very prudent approach,” Porter said.
Is Reclamation’s outlook too rosy?
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Reclamation said this year’s wet conditions played a critical role in its draft proposal. After taking 2023 data into consideration, the bureau said it’s significantly less likely that the water levels in Lake Powell and Lake Mead will drop below certain critical levels — 3,490 feet and 1,000 feet, respectively — through 2026. Below 3,490 feet at Lake Powell, Glen Canyon Dam cannot generate hydroelectric power for households across the West.
Reclamation’s modeling, however, depends on 30 years of historical data — and past data is an increasingly unreliable indicator of future conditions as the basin’s climate changes, Udall said. Wet conditions, like those in the 1990s, can skew the model analysis to provide more optimistic conclusions in the proposal, called a supplemental environmental impact statement, or SEIS.
“We can’t look to previous years as a guide to the future. We can’t look to long-term averages for safety. We have had the worst years in recorded runoff,” Udall said. “The way the EIS is done, it gives us this rosy picture by utilizing really wet years in some of the modeling.”
After all, he added, in the early 2000s, water officials thought there was a 0% chance the basin would not have surplus water, and that was followed by the driest 22-year period in 1,200 years.
“Tell me how this system performs if you throw 2002, ’03 and ’04 at it, or if you throw 2020, ’21, followed by 2022. Show me what happens in those two instances because I’m almost certain this system crashes if those three years occur starting right now,” Udall said. “Are we prepared to deal with that? That’s my bottom line.”
Current water levels
A shift toward long-term planning
Resolving this near-term plan would help state and tribal officials in Colorado look to the next stage of negotiations: replacing the current management rules, which expire in 2026, for the river’s main reservoirs.
“I think it makes logical sense to pursue this for the next couple of years and focus on the long-term,” Gimbel said.
One priority for Colorado is to address overuse in the basin. Colorado and other Upper Basin states — New Mexico, Utah and Wyoming — say that the Lower Basin has been using more than its share of the river for years, arguing that’s one of the main reasons lakes Mead and Powell fell to near-catastrophic levels in the early 2020s.
“When we’re talking about addressing Lower Basin overuse, this is a start. It’s not the finish line,” Mitchell said about the near-term proposal.
The proposal did not address some of Colorado’s priorities, like accounting for water lost because of evaporation. Upper Basin states account for these losses, while Lower Basin states do not. This has been a sticking point for the four upstream states.
“Obviously we feel like evaporation and transit losses are a consequence of physics and should be addressed,” Mitchell said.
Tribes with land in Colorado, like the Ute Mountain Ute Indian Tribe, are watching the near-term process to make sure that tribes are included in the process and their water rights are not impacted, Peter Ortego, the tribe’s general counsel, said in a written statement.
The tribe is working around infrastructure, legal and financial barriers to put all of its water rights to use. For now, its members watch their water flow downstream to the Lower Basin even while being impacted by drought.
“This is especially despicable when you consider that those using the Tribe’s water can participate in conservation programs and receive compensation for not using the water they would typically consume (again, the Tribe’s water),” Ortego wrote.
As officials turn their focus toward long-term planning for the river’s future, Coloradans can look to their own mountains this winter to gauge conditions in the Colorado River Basin.
Most of the basin’s water supply comes from winter snowfall that packs onto mountains in places like western Colorado. If the mountain snowpack and basin precipitation are “crummy” this year — if the river system gets less than 11 million acre-feet — then water managers should prepare for a second bad year, Udall said, adding that these bad water years are more than twice as common now compared with the 20th century.
However, every good year makes the possibility of a bad outcome go down significantly.
“Maybe three years is such a short period of time, nothing bad is going to happen here. But the lessons of the last 24 years are: expect the unexpected,” Udall said. “Let’s hope we get through this. I suspect we will, but who knows. One really bad year and we’re going to have to start rethinking quickly how we operate the system.”