For the first time, some users of Colorado River water will not get their promised deliveries after a shortage was officially declared in response to drought-depleted flows on the over-allocated river that furnishes water to 35 million Westerners.
The U.S. Bureau of Reclamation on Monday announced the cuts totaling 613,000 acre-feet, which will be borne mostly by Arizona growers, citing actions mandated in the 2019 Drought Contingency Plan crafted by Utah and six other Western states that rely on the Colorado for water and power. Under this agreement, the river’s three lower basin states—Arizona, Nevada and California—would forego a certain amount of water deliveries depending on projected levels of Lake Mead, the nation’s largest reservoir, now about a third full.
Federal officials pointed to the warming climate, linked to a 22-year drought in the West, as the main reason for the river’s disappearing flows.
“There’s no doubt that climate change is real. We’re experiencing it every day in the Colorado River Basin and in other basins in the West,” said Tanya Trujillo, assistant secretary of Interior for water and science. “I think the best strategy for planning is to think about a broad range of scenarios and a broad range of potential hydrology, and to work closely with our partners in the basin to try to think through all of those scenarios.”
According to the bureau’s latest “24-month study” released Monday, Mead’s elevation will likely drop to 1,066 feet above sea level by Jan. 1. Under the drought plan and the bureau’s 2007 operating guidelines, Arizona is to give up 512,000 acre-feet next year, representing 18% of its share, and Nevada another 21,000 acre-feet.
Under Monday’s announcement Mexico’s share will be cut by 80,000 acre-feet, while California’s cuts don’t kick in until Mead is projected to fall below 1,045 feet. Meanwhile, releases from Lake Powell’s Glen Canyon, will be reduced next year to 7.48 million acre-feet next year, effectively reducing the amount of water reaching Lake Mead, which will also see releases scaled back from Hoover Dam, according to the bureau’s report.
These measures are needed to keep levels in the two lakes from reaching critically low levels. Meanwhile, the bureau forecast Mead’s level could drop to 1,050 feet, triggering more cuts.
Farmers in Pinal County, an agricultural area south of Phoenix served by the Central Arizona Project, will carry most of Arizona’s cuts, but cities and tribes may also take a hit if the situation continues to worsen at Mead.
Lake Powell in trouble
Falling in tandem with Lake Mead is Utah’s Lake Powell. On July 23, Powell’s lake level dipped to its lowest point since it began filling in the 1960s following the completion of Glen Canyon Dam.
The elevation has dropped another 4 feet since then to 3,551 above sea level and the lake is now 31.6% full. As the lake falls, more and more submerged geological features and archaeological sites become exposed. On Aug. 14, a Salt Lake Tribune reader reported seeing daylight under Gregory Natural Bridge in the lake’s Escalante Arm. Among Utah’s largest natural bridges, Gregory had been submerged for more than 50 years.
At 3.4 million acre-feet, inflows this year into Lake Powell, also fed by the San Juan, Green and Escalante rivers, are just 35% of average, according to bureau data. Meanwhile, 7.2 million acre-feet of water has been released from Glen Canyon Dam in accordance with the century-old interstate compact that apportions the Colorado’s water to the seven states.
Most of the river’s flows originate in the upper portions of the Colorado Basin in the Rockies, but disproportionate share has gone to lower basin states, under the 1922 water-sharing plan.
The Upper Basin experienced an exceptionally dry spring in 2021, with April to July runoff into Lake Powell just 26% of average despite near-average snowfall last winter, according to the report. Total Colorado River system storage today is 40% of capacity, down from 49% at this time last year.
Lake Powell pipeline seems like a pipe dream, activists say
Utah and three other upper basin states are not directly affected by the shortage declaration, but Monday’s action could serve as a warning that these states may find it difficult to expand diversions from the Colorado and its upper tributaries. If Arizona communities are getting cut off, it will be hard for Utah to justify its proposal to divert 86,000 acre-feet of Lake Powell water through a 143-mile pipeline to support rapid urban growth around St. George, critics argue.
Given current trends, Lake Powell could soon cease functioning as a reservoir and Glen Canyon Dam as a hydropower generator without substantial revisions to how the Bureau of Reclamation manages the Colorado River Basin’s water resources. Already, boating on Lake Powell has become a challenge with the closure of launch ramps and marina facilities due to low water.
“There is no climate plan for the Colorado River. There’s just the federal government and the states watching the levels drop,” Utah Rivers Council’s Zach Frankel said. “We need a climate plan for the Colorado River and we needed it five years ago. What we need right now is a moratorium on all proposed water diversions, especially the Lake Powell pipeline. There is no water to put in the Lake Powell pipeline without taking it away from existing Utah users or taking it away from the Ute Indian tribe.”
Utah officials countered that the amount of water to be moved through that pipeline is trivial compared with the reduction in river flows seen in recent years.
“Talk about a million acre-feet of water that essentially didn’t come into the system,” Shawcroft said. “We’re focused on how to handle the significant reduction in the hydrology of the Colorado River basin system, not one diversion or this diversion,” said Gene Shawcroft, chairman of the new Colorado River Authority of Utah. “Some of the cuts in the [Drought Contingency Plan] are multiple times more than what the Lake Powell pipeline diversion would be.”
Utah lawmakers formed this agency this year to advance Utah’s claims to the Colorado River as the state vies with six other states and Mexico for its slice of that shrinking pie. Its first order of business is renegotiating the river’s operating guidelines, which are set to expire in less than four years.
“We are, in Utah, very, very concerned. We’re very aware of the [river’s declining] hydrology. We understand that it could in the near future, have significant impacts. We have to understand how those impacts affect Utah along with all our partner states,” Shawcroft said. “This isn’t a win-lose. We’ve got to figure out a win-win for everybody. And that’s what the seven states are trying to figure out. How we wrap our heads around this drought that has hit us faster than we ever, ever could have conceived.”