California begins 2025 with solid start to winter snowpack, but more storms are needed

The water content of the snowpack at the station was 91% of the average to date and 37% of the average on April 1, when the Sierra snowpack is typically at its peak, he said.

"As of right now, I am feeling OK, but ... we'll need a progression of monthly storms to keep going," Reising said, adding that the northern half of the state has seen a series of storms but the south has been dry.

The snowpack functions as a huge frozen reservoir, providing nearly a third of the water used annually in California as it melts and runs off into streams and rivers in the spring. The state has built a complex system of canals and dams to capture that water and store it in huge reservoirs so it can be used the rest of the year when it doesn't rain or snow.

The measurements are closely watched in California, which is the nation's most populous state with 39 million people, and also responsible for growing more than a third of the country's vegetables and three-quarters of its fruit and nuts. The health of the snowpack helps determine whether California will have a difficult time providing water throughout the summer to farms and cities.

Many of California's state-run reservoirs are at two-thirds or three-quarters of their capacity, and well above the historical average for the start of the year, thanks to two years of above-average snowpack conditions, state data shows. Last week, California officials told farms and cities that rely on state water supplies that they would get more water than previously planned because of strong storms at the end of 2024. They can now expect to get 15% of their requested supplies instead of 5%, and that number could go up if the wet weather continues.

The survey was the first in a seasonal series of manual measurements at Phillips Station. The department also collects measurements with electronic instruments at other sites, and said that statewide the snowpack is 108% of average.

A year ago, the state began the season with below-normal mountain snowpack and a water content of about 25% of the average. By April, the water content measured 110% of the average. That followed a massive snowpack to start 2023, after a series of atmospheric rivers helped pull the state out of a three-year drought.