Cuts are expected in the Colorado River for Arizona, Nevada and Mexico.

SALT LAKE CITY (AP) — The federal government is expected to announce water shortages Tuesday for states that rely on the Colorado River as drought and climate change reduce river flows. and the reservoirs that store it are depleted.

The Colorado River supplies water to 40 million people in seven Mexican states along the American West and helps feed an agricultural industry worth $15 billion a year. Cities and farms across the region are anxiously awaiting official hydrology projections — projections of future water levels in the river — that will determine the extent and scope of cuts to their water supplies.

Water officials in Arizona, California, Colorado, Nevada, New Mexico, Utah and Wyoming are expecting federal officials to approve the Lake Mead project — located on the Nevada-Arizona border and the largest man-made reservoir in the United States. Reservoirs – could become dangerously low, disrupting water supplies and hydroelectric production and reducing the amount of water allocated to Arizona and Nevada, as well as Mexico.

And that’s not all: State officials are also scrambling to meet a deadline set by the U.S. Bureau of Reclamation to cut their water use by at least 15 percent in order for the river to recover. The water level in the storage reservoirs can be prevented from falling further.

Together, the estimates and cutback deadlines are presenting Western states with unprecedented challenges and facing difficult decisions about how to plan for a droughty future.

University of Oxford hydrologist Kevin Wheeler said that while the Bureau of Reclamation is “very focused on just getting through next year,” any cutbacks would likely need to last longer.

“What the science contributes is that it’s pretty clear that these deficits are only going to persist until the drought ends or we realize they’re actually going to get worse and the cuts are going to get deeper,” he said. ” They said.

The expected cuts announced Tuesday build on a plan that seven states, as well as Mexico, signed in 2019 to help maintain reserve levels. Under the plan, the amount of water allocated to states depends on the water level on Lake Mead. Last year, the lake dropped so low that the federal government declared a water shortage for the first time in the region, triggering mandatory cuts in 2022 for Arizona and Nevada, as well as Mexico.

Officials expect hydrologists to project further lake declines, leading to additional cuts in Nevada, Arizona and Mexico next year. Cuts are not expected in states with high-priority water rights.

Reservoir levels have been falling for years — and faster than experts predicted — due to climate change and a 22-year drought caused by overuse of the river. Hotter temperatures and less spring snowmelt have reduced the amount of water flowing through the Rocky Mountains, where the river rises 1,450 miles (2,334 km) southwest before emptying into the Gulf of California.

Already, extraordinary measures have been taken this year to keep water in Lake Powell, the other major Colorado River reservoir, which sits upstream of Lake Mead and straddles the Arizona-Utah border. The lake’s water flows through the Glen Canyon Dam, which generates enough electricity to power 1 million to 1.5 million homes each year.

After Lake Powell’s water level dropped enough to threaten hydropower production, federal officials said they would withhold an additional 480,000 acre-feet (156 billion gallons or 592 million cubic meters) of water to ensure The dam can still generate energy. . This water would normally flow into Lake Mead.

Under Tuesday’s shortfall, Arizona is expected to lose slightly more water than it did this year, when 18 percent of its supply was cut. In 2023, it will lose an additional 3%, a total reduction of 21% from its initial allocation. Central Arizona farmers will endure massive cuts, as they did this year.

Mexico is expected to lose 7% of the 1.5 million acre-feet it receives from the river each year. Last year it fell by around 5 percent. The water is a lifeline for northern desert cities that include Tijuana and a large farm industry in the Valley of Mexico, just south of the border with California’s Imperial Valley.

Nevada is also poised to lose water — about 8% of its supply — but most residents won’t feel the effects because the state recycles the majority of its domestic water use and its full supply. Does not use allocations. Last year, the state suffered a loss of 7 percent.

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Neishadham reported from Washington. The Associated Press is supported by the Walton Family Foundation for coverage of water and environmental policy. AP is solely responsible for all content. For all of AP’s climate coverage, visit https://apnews.com/hub/climate-and-environment

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