California’s snowpack is now one of the largest ever
The year will go down in the record books as one of the biggest snowpacks in California history after the Department of Water Resources conducted its fourth snow survey of the season at Phillips Station on Monday.
The manual survey recorded 126.5 inches of snow depth and an equivalent snow water of 54 inches, which is 221 percent of the average for this location on April 3. Snow water equivalent measures the amount of water contained in the snowpack and is a key component of DWR’s Water Supply Forecast. DWR’s electronic readings from 130 snow sensors located across the state show the statewide snow water equivalent of 61.1 inches, or 237 percent of average for the date.
“This year’s severe storms and flooding are the latest example that California’s climate is becoming more extreme,” said DWR Director Karla Nemeth. “After the three driest years on record and the drought’s devastating impacts on communities across the state, DWR has moved quickly to respond to flooding and predict future snowmelt. We have provided flood relief to many communities that just a few months ago were dealing with severe drought impacts.”
Just as years of drought demonstrated that California’s water system is facing new climate challenges, this year is showing how the state’s flood infrastructure will continue to rise to the climate’s challenges of moving and storing as much of that water as possible. of floods.
This year’s April 1 result from the statewide snow sensor network is higher than any reading since the snow sensor network was established in the mid-1980s. Before the network was established, the statewide April 1, 1983 summary from manual snowpack measurements were 227 percent of average. The April 1, 1952 statewide total for snowfall measurements was 237 percent of average.
“This year’s result will go down as one of the biggest snow years on record in California,” said Sean de Guzman, manager of DWR’s Snow Observations and Water Supply Forecasting Unit. “While the 1952 snow course measurements showed a similar result, there was less snow flow at that time, making it difficult to compare with today’s results. Because additional snow courses were added over the years, it’s difficult to accurately compare results over the decades, but this year’s snowpack is definitely one of the largest the state has seen since the 1950s.
For California snowfall measurements, only 1952, 1969 and 1983 recorded statewide totals above 200 percent of the April 1 average. While above average across the state this year, snow varies significantly by region. The Southern Sierra snowpack is currently 300 percent of its April 1 average and the Central Sierra is at 237 percent of its April 1 average. However, the critical Northern Sierra, home to the state’s largest surface water reservoirs, is at 192 percent of its April 1 average.
The size and distribution of this year’s snow is also posing a high risk of flooding in areas of the state, particularly in the Southern San Joaquin Valley. DWR’s Federal State Flood Operations Center (FOC) is supporting the emergency response in the Tulare Lake Basin and Lower San Joaquin River by providing flood warfare specialists to support ongoing flood response activities and by providing long-term advanced planning. FOC’s Snow Observations and Water Supply Forecasting Unit and DWR 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 from DWR’s snowmelt forecasting tools, including the Sn ASO Observatory) surveys.
Storms this year have caused impacts across the state, including flooding in the community of Pajaro and communities in Sacramento, Tulare and Merced counties. FOC has helped Californians by providing over 1.4 million sandbags, over 1 million square feet of plastic sheeting and over 9,000 feet of reinforcing mesh walls across the state since January.
On March 24, DWR announced an increase in projected State Water Project (SWP) supplies to 75 percent, from the 35 percent announced in February, due to improved state water supplies. Governor Newsom has rescinded some emergency drought provisions that are no longer needed due to improved water conditions, while maintaining other measures that continue to build long-term water resilience and support regions and communities still facing supply challenges with water.
While winter storms have aided snowpack and reservoirs, groundwater aquifers are much slower to recover. Many rural areas are still experiencing water supply challenges, particularly communities that rely on groundwater supplies that have been depleted due to prolonged drought. Long-term drought conditions in the Colorado River Basin will also continue to affect water supplies 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 continue in the future.
DWR conducts five media-oriented snow surveys at Phillips Station each winter near the beginning of each month, from January through April and, if necessary, in May. Given the size of this year’s snow with more snow in the forecast, DWR anticipates conducting a snow survey in May at Phillips Station. This is tentatively scheduled for May 1.