Nevada snowpack improves, but deficits persist

Yahoo

13-03-2025

Hole in Mountain SNOTEL, East Humboldt Mountains, Clover Valley Basin, February 27, 2025 (Photo Credit: Logan Jamison, USDA Natural Resources Conservation Service)
A string of storms in California and Nevada brought some moisture back to the West this winter, improving snowpack in the region, but not enough to erase deficits in the state.
Snowpack is a crucial source of water for Nevada and the West. As snowpack melts, it recharges ecosystems and replenishes reservoirs that provide drinking water for millions of people and irrigation water for millions of acres of farmland.
Most of Nevada's water supply starts as snowpack that accumulates in high elevations during the winter before melting in the spring, meaning substandard snowpack can leave the state with a weak water supply outlook.
Nevada has seen above normal snowpack the last couple of winters, but this year researchers are seeing a wide range of conditions that could negatively impact Nevada's water supply this summer — including well below normal snowpack in eastern and southern Nevada, as of March.
Last month, snowpack in the state fell well below normal for that time of year, following disappointing snowfall and persistently warm temperatures. Those conditions greatly improved this month, after a flurry of late-February storms helped push snowpack in Nevada and the Eastern Sierra to about normal at 94% of historical median.
Still, that snowpack improvement has not been distributed evenly, according to the Department of Agriculture's Natural Resource Conservation Service.
Snowpack across the Sierra Nevada mountains and the Upper Colorado Basin — two major water sources for Reno and Las Vegas, respectively — have remained below normal for this time of year, according to the agency's Nevada Water Supply Outlook.
There is still time for conditions in Nevada to improve, say federal water managers. The National Weather Service Climate Prediction Center's outlooks favor a likely colder and wetter pattern over the next month in the West, which could be favorable for snow accumulation and help improve conditions for the state.
'Weather forecasts look promising for additional storms through the middle of March. Hopefully the storm track benefits the entire state, especially eastern and southern Nevada where drought conditions have worsened in recent months,' reads the report.
Snowpack in the Upper Colorado Basin — the largest source of water for Lake Mead — improved slightly since last month, but remains below normal for this time of year. The Upper Colorado Basin's snowpack is at 88% of the historical median, up 3 points from last month. Precipitation in the region was also about normal in February.
However, several basins in the Upper Colorado River have recorded low snowpack that could impact water supply to Lake Powell and Lake Mead if they do not improve. Lake Powell's water levels directly affect Lake Mead because water from Lake Powell is eventually released to Lake Mead.
Based on historic data there is less than a 10% chance the Upper Colorado will reach a normal peak snowpack by early April. Reservoir storage in Lake Mead and Lake Powell is also at just 36% of capacity.
The Spring Mountains in Southern Nevada — the biggest source of groundwater for the region — finally got the first significant snowstorm on Valentine's Day. Snowpack for the mountains reached 55% of the historical median in March, but it is becoming 'very unlikely' the mountains will reach normal snowpack by April, according to the report.
As of March, extreme drought has also persisted in a majority of Clark, Lincoln, and Nye counties.
Snowpack in several basins that supply water for the Reno-Sparks area — including the Walker River Basin, Carson River Basin, and Lake Tahoe Basin — have also remained below normal despite recent February storms.
Fortunately, robust reservoir storage in the region is expected to supplement water supply this summer, according to the report. Lake Tahoe is currently storing enough water to meet demands on the Truckee River, hitting 73% capacity in March. Water levels at Lake Tahoe are also projected to rise about another foot during snowmelt this spring and summer.
Moderate drought conditions extended into parts of Washoe, Lyon, Churchill, and Storey counties in March.
Other basins in northern Nevada greatly benefited from February storms, which significantly boosted snowpack and precipitation in regions along the Oregon-Nevada border.
February storms pushed snowpack in the Northern Great Basin — and the Humboldt, Owyhee, Snake and Clover Valley basins — above historical medians. Hydrologists also said they expect incoming storms forecasted in March to push snowpack in those basins above their normal peak snow amounts by April.
Snowpack in Eastern Nevada — which covers the majority of White Pine County and part of Eureka County — has also failed to improve despite February storms. Snowpack in Eastern Nevada is well below normal at 55% of median, compared to 115% at this time last year.
While February storms brought drought improvements to western Nevada, in eastern Nevada where dry conditions persisted in February severe drought expanded into White Pine and Eureka counties.
Three of the four main snow accumulation months are over making it 'very unlikely' that eastern Nevada will reach normal snowpack by April, said hydrologists in the Nevada Water Supply Outlook.