After years of severe drought combined with climate change, the water level in Lake Powell, the second largest reservoir on the Colorado River, has dropped to just 24% of full capacity and is continuing to fall to unprecedented levels. seen since the reservoir was full. in the 1960s.
In an effort to boost the shrinking reservoir, the federal government on Tuesday announced that it would withhold large amounts of water this year to reduce the risk of the lake falling below the level at which the Glen Canyon Dam would fall. no longer produces electricity.
“Today’s decision reflects the truly unprecedented challenges facing the Colorado River Basin and will provide operational certainty over the coming year,” said Tanya Trujillo, assistant secretary for water and science. of the federal Interior Department, said in a statement announcing the measures.
This is the first time the U.S. Bureau of Reclamation has invoked its authority to alter its operations in this way at the Glen Canyon Dam on the Arizona-Utah border. The agency said the plan is to protect the infrastructure at the dam and its hydroelectric generation capacity, and to ensure that water supplies will continue to be available to the nearby city of Page, Ariz, and part of the Navajo Nation.
This plan is intended to reduce the risk of Lake Powell falling to an extremely low level. The measures would involve releasing about 500,000 acres of water from the Volcanic Canyon Reservoir, located upstream, and leaving an additional 480,000 acres in Lake Powell by reducing the amount of water released from the Glen Canyon Dam during the year. now.
By comparison, California, Arizona and Nevada used 6.8 million acres of Colorado River water in 2020.
The Colorado River supplies water to nearly 40 million people in cities from Denver to Los Angeles and to farmland from the Rocky Mountains to the US-Mexico border. The river has been regularly overused and its reservoirs have been severely depleted since 2000 during a severe drought that scientific studies show is being enhanced by global warming. bridge.
The federal government last month proposed a plan to combat the decline in Lake Powell to states in the Colorado River Basin. In a letter, Trujillo asked seven river-dependent states to contribute to the plan.
“We believe that additional actions are needed to reduce the risk of Lake Powell falling” to 3,490 feet below sea level, Trujillo said in the letter.
Trujillo warned that below the 3,490 feet threshold, Glen Canyon Dam facilities face “unprecedented operational reliability challenges, with water users in the Basin facing increased instability increases, downstream resources may be affected, the western grid will be at risk and unstable.”
The water level of the reservoir on the Arizona-Utah border is currently about 32 feet above that threshold.
“We are approaching operating conditions for which we have only very limited practical operational experience,” Trujillo said in the letter.
Representatives from the seven states responded in a letter on April 22, saying they agreed that “additional cooperative actions should be taken this spring to reduce the risk of Lake Powell falling below normal.” important high.”
State officials said they support the government’s plan to drain Lake Powell “to reduce the risk we all face.”
To cut the total annual release from the Glen Canyon Dam to 7 million acres, the Bureau of Reclamation is keeping the 350,000 acres of water in Lake Powell that was retained earlier this year and will retain an additional 130,000 acres. UK – ends at the end of September.
David Palumbo, the office’s acting commissioner, praised the seven states’ swift response. While implementing these short-term measures, “we recognize the importance of simultaneous long-term planning to stabilize our reservoirs before we face a major crisis,” he said. greater crisis.”
Trujillo said all those who depend on the river “must continue to work together to reduce usage and think of additional proactive measures we can take”.
Even if less water flows downstream this year, managers with the Metropolitan Water District in Southern California say they have stored enough Colorado River water to fill the aqueduct now and won’t have to. limit the amount of water assigned to the area.
“Drought and climate change are creating incredible challenges that need to be addressed both in the short and long term,” said Adel Hagekhalil, superintendent of the school district. He said that while reduced discharges at Glen Canyon Dam “will not affect our ability to supply the Colorado River this year, they are a reminder that the Southwest is in the territory.” untapped water”.
Hagekhalil said the district is urging all Southern Californians to “immediately cut water use by 20% — or more in some areas — to prolong supplies and available storage.” ”
MWD imports water from the Colorado River and Sacramento-San Joaquin River Delta, serving agencies across six counties that feed 19 million people – about half the state’s population. Supply from the Delta, provided through the State Water Project, has fallen to just 5% of its full allocation this year.
Shortages in the State Water Project last week prompted MWD to order water restrictions in areas heavily dependent on those supplies. But cities that rely largely on the Colorado River water will not face mandatory restrictions.
“As for the Colorado system, we’ve been preparing for years like this, so we can bring Colorado River water into the future,” said Bill Hasencamp, MWD’s Colorado River Resources manager.
“We can start to have limits on Colorado,” Hasencamp said. “But it’s still a few years away before we predict we’ll get to that level. So at least for the next two to three years we have enough supply to fill the pipes.”
The Metropolitan Water District’s approach, with mandatory water restrictions in some areas and none in others, has been criticized by some.
Felicia Marcus, a Stanford University researcher and former chair of the California state water board, said she thinks leaving areas dependent on the Colorado River without mandatory restrictions, and no cuts across the region, like “high bet gambling”.
“Even if they’ve had enough for this year, the question is, will they have enough for the next three to five years?” Marcus said. “To me, it seems like we need to have more dramatic action.”
Over the past few years, state and federal officials have repeatedly negotiated agreements to try to reduce the risk of reservoirs to extremely low levels.
In 2019, representatives from seven states gathered on a terrace overlooking the Hoover Dam and signed a series of agreements called Drought Contingency Plans, including a pact between California, Arizona, and Nevada to take less water from the river to try to limit the decline. in Lake Mead, the nation’s largest reservoir.
Last summer, the federal government first declared a water shortage on the Colorado River, causing significant cuts in the water supply to Arizona, Nevada and Mexico.
With reservoirs continuing to dwindle, water officials from California, Arizona and Nevada signed another agreement in December to significantly reduce the amount of water they take in, aiming to keep an additional 1 million acres in Lake Mead within two years.
Some of that will be reduced through payments for conserving water in farming areas, including payments to growers to leave some fields dry and uncultivated. cultivation. The tribes also agreed to leave water in Lake Mead in exchange for payments.
Bart Fisher, a farmer who is a member of the Colorado River Board of California, says the latest short-term plan is “another kind of Colorado River Hedgehog Day.” Over the past few years, repeated efforts have not been enough, he said, and state representatives need to start negotiating a new set of rules to manage shortages beyond 2026.
“In California at least, the consensus is let’s stop whaling,” Fisher said.
“Let’s sit down and start serious negotiations about the next set of guidelines,” he said. “The clock is ticking. We need to get started. “
Jennifer Pitt, director of the Colorado River program for the National Audubon Society, wrote in an article last month that the Colorado River Basin is moving closer to “Day Zero,” a term that emerged in 2018 when Cape Town, South Africa, facing a real danger of running out of water.
“In recent days, state and federal officials have announced plans to address the immediate crisis. Pitt writes. “They do nothing to mitigate the unrelenting risk of the Colorado River’s unbalanced water supply and demand, because all they do is move water from one place to another.”
She emphasized that climate change is drying up the Colorado River and that over the past two decades, the river’s flow has been about 20% less than the 20th-century average. Conditions in the river basin today are likely to worsen in the coming decades.
“What is urgently needed now is for federal and state water administrators to work, in partnership with tribes and other stakeholders, to take the necessary steps to build upon it,” Pitt said. build confidence in the long-term management of the Colorado River,” Pitt said. “This will require focused and dedicated resources to develop and implement plans that bring water demand into balance with supply.”
https://www.latimes.com/environment/story/2022-05-03/feds-reduce-water-release-colorado-river-lake-powell-reservoir Feds will release less water from Colorado River reservoir