DWR reports record snowpack in Sierra Nevada Mountains

On Monday, a manual survey conducted by DWR – the fourth snow survey of the season at Phillips Station – recorded 126.5 inches of snow depth and a snow water equivalent of 54 inches, which is 221% of average for the location on April 3.

DWR officials said the snow water equivalent measurement is important because it is a key component of the state’s water supply forecast. Officials said DWR’s electronic readings from 130 snow sensors placed throughout the state indicate the statewide snowpack’s snow water equivalent is 61.1 inches, or 237% of average for April 3.

“This year’s severe storms and flooding is the latest example that California’s climate is becoming more extreme,” DWR Director Karla Nemeth said in a statement. “After the driest three years on record and devastating drought impacts to communities across the state, DWR has rapidly shifted to flood response and forecasting for the upcoming snowmelt. We have provided flood assistance to many communities who just a few months ago were facing severe drought impacts.”

According to DWR, this year’s April result from the statewide snow sensor network is higher than any other reading since the network was established in the mid-1980s

“This year’s result will go down as one of the largest snowpack years on record in California,” Sean de Guzman, manager of DWR’s Snow Surveys and Water Supply Forecasting Unit, said in a statement. “While 1952’s snow course measurements showed a similar result, there were fewer snow courses at that time, making it difficult to compare to today’s results. Because additional snow courses were added over the years, it is difficult to compare results accurately across the decades with precision, but this year’s snowpack is definitely one of the biggest the state has seen since the 1950s.”

DWR said only 1952, 1969 and 1983 recorded statewide results above 200% of the April 1 average for California’s snow course measurements. 

“While above average across the state this year, snowpack varies considerably by region,” officials said. “The Southern Sierra snowpack is currently 300% of its April 1 average and the Central Sierra is at 237% of its April 1 average. However, the critical Northern Sierra, where the state’s largest surface water reservoirs are located, is at 192% of its April 1 average.”

Due to the size and distribution of this year’s snowpack, DWR said there is a severe flood risk to some areas of the state.

“DWR’s State-Federal Flood Operations Center (FOC) is supporting emergency response in the Tulare Lake Basin and Lower San Joaquin River by providing flood fight specialists to support ongoing flood response activities and by providing longer-term advanced planning activities,” officials said. “The FOC and DWR’s Snow Surveys and Water Supply Forecasting Unit are helping local agencies plan for the spring snowmelt season by providing hydraulic and hydrologic modeling and snowmelt forecasts specific to the Tulare Lake Basin that are informed by DWR’s snowmelt forecasting tools, including Airborne Snow Observatory (ASO) surveys.”

DWR officials said that even though continued winter storms have helped the snowpack and fill reservoirs, groundwater basins have been much slower to recover.

“Many rural areas are still experiencing water supply challenges, especially communities that rely on groundwater supplies which have been depleted due to prolonged drought,” officials said. “Long-term drought conditions in the Colorado River Basin will also continue to impact the water supply for millions of Californians. The state continues to encourage Californians to make water conservation a way of life as more swings between wet and dry conditions will continue in the future.”

DWR said it anticipates conducting another snow survey at Phillips Station in May, tentatively scheduled for May 1.