California snowpack survey finds only 59% of average moisture

DWR snowpack survey

California Department of Water Resources crew collect a snowpack sample at Phillips Station near Lake Tahoe April 1 — photo courtesy DWR

The Department of Water Resources conducted the fourth snow survey at the Phillips Station snow course April 1. The manual survey recorded 49.5 inches of snow depth and a snow water equivalent of 21 inches, which is 83% of average for this location. The snow water equivalent measures the amount of water contained in the snowpack and is a key component of DWR’s water supply forecast.

Measurements from DWR’s electronic snow survey stations indicate that statewide the snowpack’s snow water equivalent is 16.5 inches, or 59% of average for the date. April 1 is typically when California’s snowpack is the deepest and has the highest moisture content.

“While there is some snow on the ground today at Phillips Station, there is no doubt California is in a critically dry year. State agencies, water suppliers and Californians are more prepared than ever to adapt to dry conditions and meet the challenges that may be ahead,” said DWR director Karla Nemeth. “With climate change impacting how precipitation falls in California, ongoing water efficiency and long-term efforts like recycling water, capturing stormwater, and planting water-friendly landscapes are essential to securing California’s water future.”

While the Southern Sierra remains well below average for both rain and snow, the picture is somewhat different in the northern and central part of the state where California typically receives 75% of the state’s annual precipitation.

The few storms that affected California this year have been colder, bringing more snow than rain. This is a positive sign for the Sierra snowpack which accounts for 30% of California’s fresh water supply in an average year.

For water year 2021, the snowpack in the northern and central Sierra peaked at 70% of average. However, rain is below 50% of average, which ties this year for the third driest year on record.

The severity of dry conditions is particularly evident in the Feather River watershed where water levels at Lake Oroville, the State Water Project’s largest reservoir, are currently at 53% of average. Lake Oroville is located about 80 miles north of Sacramento.

Statewide, following a below-average 2020 water year, California’s major reservoirs are at just 50% of overall capacity. The amount of water expected to enter California’s reservoirs when the snowpack melts is projected to be just 58% of average.

With dry conditions continuing to affect California’s water supply, DWR recently announced an adjustment to the State Water Project allocation for 2021. The department now expects to deliver 5% of requested supplies this year, down from the initial allocation of 10% announced in December.

California is better prepared for drought than in the past. Following the 2012-2016 drought, DWR enacted many programs focused on managing the state’s water through a strategic, integrated approach with a strong emphasis on water use efficiency and conservation.

The California Department of Water Resources contributed this article.