SACRAMENTO, Calif. – The Department of Water Resources (DWR) today conducted the April snow survey at Phillips Station. The manual survey recorded 39.5 inches of snow depth and a snow water equivalent of 17 inches, which is 70 percent 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. Statewide, the snowpack is 90 percent of average for this date. Given the forecast for storms early next week, DWR conducted the in-person snow survey ahead of April 1.
While DWR’s Snow Surveys and Water Supply Forecasting Unit strives to conduct measurements as close to the first of the month as possible, DWR must schedule surveys around forecasted storm activity to ensure the safety of DWR staff and invited media. The anticipated storms this weekend and early next week may boost the official April 1 average for statewide snowpack and DWR will provide an update on Tuesday.
The April measurement is a critical marker for water managers across the state, as it is typically the time when the snowpack reaches its maximum volume and begins to melt. DWR’s water supply forecasts use data from the April 1 snowpack to calculate how much snowmelt runoff will eventually make its way into California’s rivers and reservoirs.
While the snowpack has caught up to near normal, broad swaths of Southern California remain exceptionally dry and below average for rainfall. This includes the Los Angeles region, which as of today has only received 45 percent of its average rainfall so far this water year.
“It’s great news that our state’s snowpack has recovered from several weeks of extremely dry conditions in the heart of our winter storm season,” said DWR Director Karla Nemeth. “However, it’s not a wet year across the entire Sierra Nevada. The north has great snowpack, but snowpack is less than average in the central and southern part of the mountain range. That snowpack ultimately flows to the Delta, and the regional disparity affects how much water the State Water Project will be able to deliver.”
Measuring California’s snowpack is a key component that guides how California’s water supplies are managed. On average, California’s snowpack supplies about 30 percent of California’s water needs. Its natural ability to store water is why California’s snowpack is often referred to as California’s “frozen reservoir.”
The data and measurements collected from DWR and its partners with the California Cooperative Snow Surveys Program help inform the water supply and snowmelt runoff forecasts, known as the Bulletin 120, that help water managers plan for how much water will eventually reach state reservoirs in the spring and summer. This information is also a key piece in calculating State Water Project allocation updates each month.
“We are very thankful to be ending March where we are now with more snow in the forecast next week, especially considering the dry start to the year,” said Andy Reising, manager of DWR’s Snow Surveys and Water Supply Forecasting Unit. “From major storms in November and December to a bone-dry January, then back to major storms in February and March, this year is a lesson in why we can never know for certain what our water picture will look like until we get to the end of our traditional wet season.”
Before storms in February and March, California was experiencing an excessively dry January that stalled critical growth of the snowpack and contributed to the dangerous conditions that led to devastating wildfires in Southern California. To prepare for the next drought, DWR and Governor Newsom have taken actions to secure and protect California’s water supply in the face of growing climate extremes while balancing the needs of the environment. In January, Governor Newsom issued an executive order to make it easier for local and regional agencies to maximize groundwater recharge, ensuring California is able to capture and store as much water as possible during high winter flows.
California is also working with the scientific community to adopt the best available science for the state’s water management. A recently released report shows that DWR’s investments in pursuing new strategies known as Forecast Informed Reservoir Operations, which provides flexible water management based on the newest forecasting technologies, can both reduce flood risk for downstream communities and benefit water supplies during dry period.
This fall, the State Water Project received a new operating permit after years of working with the U.S. Bureau of Reclamation and partners at state and federal fish agencies, that will address the dual challenges of climate change impacts and endangered species protections.
Thanks to efforts to capture as much water as possible from this year’s storms, reservoirs across the state are currently 115 percent of average.
DWR conducts four or five snow surveys at Phillips Station each winter near the first of each month, January through April and, if necessary, May.
For California’s current hydrological conditions, visit https://cww.water.ca.gov
Listen to the report by KMJ’s Liz Kern.
