Despite some improvements in water conservation, Nevada and the U.S. face mandatory water cuts for the fourth consecutive year as drought and climate change continue to threaten Lake Mead, federal officials announced Thursday.

Federal water authorities announced that Stage 1 water cuts – the least severe shortage – would be needed next year to maintain Lake Mead’s water levels.

Lake Mead’s water level is expected to fall below 1,075 feet in 2025, a level that would trigger a water shortage, according to a 24-month study from the Bureau of Reclamation.

Lake Mead is currently 37 percent full, the agency said. The federal Water Resources Agency warned that if water levels continue to drop, Lake Mead will most likely be unable to supply water downstream or generate hydroelectric power.

The cuts will cause Nevada to lose about 7% of its water allotment, or 21,000 acre-feet of water. However, the cuts are not expected to impact Nevada water users.

Southern Nevada is allowed to take 300,000 acre-feet of water from the Colorado River, but has not fully used it for years thanks to conservation efforts. Last year, Nevada used only about 188,000 acre-feet of water.

“We are well below our total allocation, and the water we clean, the water we don’t use, is water we can store as a reserve for the future,” said Mack Bronson, spokesman for the Southern Nevada Water Authority.

Cuts are also expected in Arizona, California and Mexico starting next year. Arizona will lose 18 percent of its total allocation for the Colorado River, Mexico 5 percent and California 7 percent.

The cuts announced Thursday fall into the same “Stage 1” category declared in 2021 and 2022 when the first federal cuts to the Colorado River took effect. A “Stage 2” water shortage for 2023 resulted in even steeper cuts.

The Colorado River basin provides drinking water to 40 million people in the lower basin (Arizona, California, Nevada and Mexico) and the upper basin (Colorado, New Mexico, Utah and Wyoming).

States in the lower and upper Colorado River basins are each allocated 7.5 million acre-feet of water, for a total of 15 million acre-feet. But officials admit that only 12.4 million acre-feet of water flows out of the river each year, and that water volumes are continuing to decline due to climate change.

Federal hydraulic studies show that water flow is likely to decline by an additional 3 million acre-feet over the next decade. Based on Reclamation’s latest hydraulic models, Lake Mead’s water level could drop to 1,050 feet by the end of 2025, or cause a Stage 2 water shortage, making further conservation efforts essential and prompting even greater cuts to water allocations.

“The future will be warmer and drier in the Colorado River basin, and there will be years when our allocation will be reduced,” Bronson said.

In recent years, Nevada has passed a number of laws to reduce water use in anticipation of even greater water cuts. These include a 2021 law banning ornamental grass in most public areas, a 2022 Clark County resolution limiting pool sizes and a 2023 law to phase out the use of water-intensive septic tanks.

“The steps we have already taken to reduce our water usage put us well on track to handle any future savings,” Bronson said.

The Southern Nevada Water Authority was able to reduce its water use to 89 gallons per person per day last year, the lowest since the early 1990s. But due to hotter and drier weather conditions this summer, per-person water use is expected to increase this year.

“Last year was a really good year, but we also had a lot of help from Mother Nature,” Bronson said. “Compare that to the summer we’re experiencing right now, with a record July, our warmest summer on record. So we’re seeing that water use this year is certainly a little higher than last year, but we’re still below the average of the last three years.”

Federal officials also expressed optimism this week about recent water conservation efforts in the region ahead of the release of the 24-month study.

On Wednesday during the Second Annual Southern Nevada Water SummitBureau of Reclamation Commissioner Camille Calimlim Touton praised the voluntary efforts of states in the Colorado River Basin to reduce their water use and highlighted an agreement by the Imperial Irrigation District in California, which decided this week to up to 700,000 acre-feet of water in Lake Mead until 2026.

“These conservation programs work. Yes, it’s painful, but it works, and it preserves a very important and vital water source for this entire area,” Reclamation hydrologist Shana Tighi said during Wednesday’s summit.