Willow Flat SNOTEL, Walker Basin, January 27, 2025. (Photo Credit: Jeff Anderson/Natural Resource Conservation Service)
Nevada’s water supply outlook is in trouble after snowpack in the state fell below normal for this time of year, following disappointing snowfall and persistently warm temperatures.
Most of Nevada’s water supply starts as snowfall that accumulates in the mountains during the winter before melting in the spring, meaning substandard snowpacks can leave the state with a weak water supply.
February marks the half-way point of the snow accumulation season in Nevada, but conditions have trended in the wrong direction since New Year’s Day, according to the Department of Agricultural Natural Resources Conservation Service’s water supply outlook report.
While early data hinted at the possibility of another healthy water year for Nevada, snowpack percentages are down significantly across the Sierra Nevada mountains and the Upper Colorado Basin, two major water sources for the state.
December data recorded above normal early snowpack in Nevada, but an abnormally dry January resulted in snowpack across Nevada and the Eastern Sierra dropping by about 41% in a month. Snowpack in the state is now below normal at 73% of median.
Warm temperatures also contributed to the lack of snow accumulation in Nevada. In areas of the state that did receive near-normal precipitation, warm temperatures prevented snow from forming, meaning that water could not be stored for later months in the form of snowpack.
“Most of the storms we’ve had this winter, including the ones in early February, haven’t been cold enough. Storms have often brought rain instead of snow to valleys and up to the middle elevations in the mountains,” according to the report.
Outside of Nevada, snowpack in the Upper Colorado Basin — the largest source of water for Lake Mead — fared better, falling by about 6% from January to February. Snowpack in the Upper Colorado Basin, which supplies the majority of Las Vegas’ water, is now at 85% of normal for this time of year.
The Spring Mountains in southern Nevada, the biggest source of groundwater for the region, has continued its dismal pace with just 1% of the median snowpack.
Snowpack across the Sierra Nevada basins — which provides much of northern Nevada’s water supply — saw the steepest declines across Nevada.
Snowpack in the Lake Tahoe and Truckee River basins — both major sources of water for the Reno-Sparks area — declined by about 50% from January to February.
From January to February, snowpack in the Lake Tahoe Basin declined well below normal to 59% of median after reaching 115% of median a month earlier. During that same time, the Truckee River Basin snowpack also fell well below normal to 68% of median after reaching 129% above median a month prior.
Snowpack in the Carson River and Walker River basins also decreased by half since January 1, falling to about 58% of median.
Snowpack in the Upper and Lower Humboldt River Basin fared much better, staying at about 94% of normal for this time of year. However, both basins fell much lower than they were a month ago.
Shallow snowpacks across the Sierra Nevada basins may exacerbate water shortages in Nevada’s reservoirs, according to the report.
Reservoir storage in the Lake Tahoe Basin and the Truckee River Basin are at about 60% capacity as of February 1, compared to 70% the same time last year.
Reservoir capacity in the Carson River Basin and Walker River Basin are even lower at about 48% as of February 1, compared to 78% the same time last year.
Drought expanded further into southern and eastern Nevada after below normal precipitation in January. About 65% of Nevada is now in moderate to exceptional drought due to precipitation deficits over the last six months.
While Nevada’s water outlook is grimmer than a month ago, hydrologists said storms in early February have broken the state’s dry pattern, and conditions are likely to improve.
“Hopefully the next two months bring colder storms to fill in the lower elevation snow and increase high elevation snow. That is exactly what happened by April 1, 2018 after a miracle March brought a late season come-back to all elevations,” reads the report prepared by Nevada Snow Survey water supply specialist, Jeff Anderson, and Nevada Snow Survey hydrologist, Jason Welz.