Water Supply in Southwest at Risk as Snowpack Plummets

Concerns are mounting about the water supply in the Southwest as snowpack levels in key regions plummet. The snowpack in the Rockies and Sierra Nevada, which feed vital reservoirs like Lake Mead and Lake Powell, was strong in November but has since flatlined in some areas.

While Colorado initially reported a 10-year high of 134 percent of its 30-year median snowpack, levels had dropped precipitously by the end of December.

Ten basins in the region are now below 50 percent of the median snow water equivalent—a measure of the water contained in the snow—for this time of year, according to the U.S. Department of Agriculture (USDA).

Newsweek reached out to the USDA Natural Resources Conservation Service via email for further comment.

Why It Matters

The water supply for major cities and agricultural areas across the Southwest depends heavily on snowmelt from the Rockies and Sierra Nevada.

Reservoirs like Lake Mead and Lake Powell, already severely depleted by an ongoing megadrought, are at 34 percent and 36 percent capacity, respectively. Insufficient snowpack could exacerbate water scarcity, impacting drinking water availability, agriculture and hydropower generation.

What to Know

The Lower Colorado-Lake Mead Basin is at just 33 percent of its median snowpack, and the Verde Basin has dropped to an alarming 5 percent.

Meanwhile, California’s Sierra snowpack, which supplies 30 percent of the state’s water, stands near average, but a “return of dry conditions looms,” according to the state’s Department of Water Resources.

Lake Mead and Lake Powell remain critically low, with recovery dependent on sufficient runoff in the coming months.

Relatively dry weather in the region could be further fueled if the La Niña weather phenomenon emerges. The National Oceanic and Atmospheric Administration’s Climate Prediction Center put the odds of a La Niña developing at 59 percent in its December 30, 2024 forecast.

What People Are Saying

Rebecca Mitchell, Colorado’s representative on the Colorado River Commission, told News 3 Las Vegas on December 31: “We did get a few storms over this past weekend, but we’re still below average.”

Andy Reising, California DWR’s snow surveys and water supply forecasting unit manager, in a statement: “We are fortunate to have had several solid snow-producing atmospheric river systems so far this season. The fall was extremely dry, so our healthy snow totals are thanks to a handful of big storm systems in November and late December. But to finish the year where we need to be, we will still need additional snow building at a regular pace throughout the winter.”

Eric Balken, executive director of the Glen Canyon Institute, previously told Newsweek: “You don’t fully know what’s going to happen with runoff or reservoirs until March. It’s kind of like trying to predict the stock market. You know, there’s all sorts of data out there that you can look at, and maybe you’ll be right, but you probably won’t be.”

What Happens Next

Snowpack levels typically peak in March, leaving a narrow window for improvement. If major storms hit, the snowpack could rebound, alleviating some concerns.

However, if dry conditions persist, water managers will need to prepare for another challenging year.

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