More water cuts for lower Colorado River Basin states
Jennifer Solis
(Nevada Current) Despite some improvements in water conservation, Nevada is facing a fourth consecutive year of mandatory water cuts, as drought and climate change continue to threaten Lake Mead, federal officials announced Thursday.
Federal water managers announced that Tier 1 water cuts — the least severe shortage condition — would be necessary next year to preserve water levels at Lake Mead.
Water in Lake Mead is projected to fall below 1,075 feet in 2025, an elevation that would trigger a water shortage, according to a 24-month study by the Bureau of Reclamation.
Lake Mead is currently at 37% capacity, according to the agency. Federal water managers have warned that if water levels continue to fall there is a high probability that Lake Mead would no longer be able to deliver water downstream, or produce hydropower.
Under the cuts, Nevada will lose about 7% of its allocation, or 21,000 acre-feet of water. However, the cuts are not expected to affect Nevada water users.
Southern Nevada is allowed 300,000 acre-feet from the Colorado River, but has not used its full allocation in years thanks to conservation efforts. Last year, Nevada only used about 188,000 acre-feet of water.
“We are well below our total allocation, and the water that we’re cleaning, the water that we’re not using, is water that we’re able to store for the future in reserve,” said Mack Bronson, the spokesperson for the Southern Nevada Water Authority.
Arizona, California, and Mexico also face cuts starting next year. Arizona will lose 18% of its total Colorado River allocation, Mexico will lose 5%, and California will face a 7% reduction.
The cuts announced Thursday are in the same “Tier 1” category declared in 2021 and in 2022, when the first federal cutbacks on the Colorado River took effect. A “Tier 2” water shortage for 2023 resulted in even steeper cuts.
The Colorado River Basin supplies drinking water to 40 million people across the lower basin — Arizona, California, Nevada and Mexico — and the upper basin: Colorado, New Mexico, Utah and Wyoming.
States in both the lower and upper Colorado River basin are each allocated 7.5 million acre-feet of water, for a total of 15 million acre-feet. But officials acknowledge only 12.4 million acre-feet flows from the river each year, and flows continue to shrink due to climate change.
Hydraulic studies by the federal government show that flow will likely decrease by another 3 million acre-feet of water in the next decade. Based on Reclamation’s most recent hydraulic models, Lake Mead water level could drop to 1,050 feet, or a Tier 2 shortage, by the end of 2025, making continued conservation efforts critical and triggering deeper cuts in allocations.
“The future in the Colorado River Basin is going to be warmer and it’s going to be drier, and we are going to have years where our allocation will be reduced,” Bronson said.
In recent years, Nevada has passed a series of laws to reduce water consumption in anticipation of steeper water cuts. That includes legislation in 2021 to ban ornamental grass from most public spaces, a Clark County resolution in 2022 to limit the size of pools, and a 2023 bill to phase out the use of water-intensive septic tanks.
“The actions that we’ve taken already to reduce our water use have us on a good path to be able to absorb any of those future reductions,” Bronson said.
The Southern Nevada Water Authority managed to reduce individual water use to 89 gallons per person per day last year, the lowest since the early 1990s. But hotter, drier conditions this summer means water use per person is likely to increase this year.
“Last year was a really good year, but we also had a lot of help from Mother Nature,” Bronson said. “Juxtapose that with the summer we’re experiencing today, where we just had a record setting July, our warmest summer ever on record. So certainly we are seeing water use trending a little bit higher this year than we did last year, but we’re still below the average over the past three years.”
Federal officials also expressed optimism about recent water conservation efforts in the region this week, ahead of the release of the 24-month study.
On Wednesday during the second annual Southern Nevada Water Summit, Bureau of Reclamation Commissioner Camille Calimlim Touton praised Colorado River basin states’ voluntary efforts to reduce water use, highlighting an agreement by the Imperial Irrigation District in California this week to leave up to 700,000 acre-feet of water in Lake Mead through 2026.
“These conservation programs are working. Yes, it’s painful, but it’s working, and it’s preserving a very critical and vital water source for this entire area,” said Reclamation hydrologist Shana Tighi during the Summit Wednesday.