Live in a valley? Snow surveys & snowpack matter

Snow Surveys

Headquartered outside Sacramento, the KISTERS North America team celebrates manual snow surveys by the California Department of Water Resources (DWR). We, hydromet nerds, ring in the new year by watching the Phillips Station media event. Nevermind that a 260-site snowpack telemetry (SNOTEL) network continuously measures and transmits data. We like the field sampling and point-in-time measurements, which quality assure data from snow sensors.

Snowpack Measurements

If you live in a valley on the coast, allow us to explain the fuss over snowpack: When snow falls and doesn’t melt away, it accumulates in cold temperatures. Money in a bank, if unspent, adds up. Snowpack serves as a water bank.

Accurate snowpack measurements in the winter determine activities in the spring. For instance, the DWR January, 2023 survey recorded a snow depth of 55.5 inches or an estimated snow water equivalent (SWE) of 17.5 inches. The data are indictors for potential flooding. More importantly, they help estimate the water supply. Sierra Nevada snowpack sustains more than 25 million people throughout California and irrigates millions of acres of agriculture. Once melted, snowpack provides about a third of the state’s water supply.

“Snow science is more important than it’s ever been, especially in the West, where snow contributes so much to our water resources,” explains Andrew Schwartz, manager of the University of California, Berkeley’s Central Sierra Snow Laboratory.

State and federal water managers closely analyze the estimated water level and water flow into rivers, streams and reservoirs. They monitor water resources to make decisions about water storage or water use across the state and western region.

Likewise, snowpack from the Rocky Mountains also supplies water for millions of people via the Colorado River. The runoff flows into Lake Mead, which supplies Hoover Dam, making it more consequential. The structure generates hydropower for 1.3 million homes in Nevada, Arizona, and California.

Warmer Temperatures

Analysis by NOAA’s National Centers for Environmental Information (NCEI) confirms 2024 was the planet’s “warmest year on record”. Warmer temperatures mean less snowfall. They also prevent snow accumulation. More rainfall is a poor consolation. Stormwater runoff more quickly enters the reservoirs and streams, evaporates, or drains out to the ocean. Natural snowpack most efficiently stores water for later use.

Worse than snow drought is less precipitation. As vegetation dries out, it becomes fire fuel. And after wildfires have been put out, the lack of trees fails to shade or protect snow on the ground. More exposure to sunshine melts snow faster. Alternatively, char on burnt trees or dust can fall on the snow, attract more sunlight, and speed snowmelt. The meltoff can carry post-fire sediment, which often worsens water quality.

All of these factors can affect the water supply forecasts — and your tap.

If you’re an agency or a research institution that needs precise snow data, we invite you to explore our portfolio of snow sensors. Alternatively, discover our comprehensive environmental software to analyze the data or decision-support system to generate accurate forecasts.