The California Department of Water Resources announced Thursday that the State Water Project will be able to deliver 100% of requested water supplies this year thanks to full reservoirs following record winter rain and snow.
For the first time since 2006, California officials have increased allocations from the vital State Water Project to 100% of requested supplies, as reservoirs across the state are nearing capacity and an epic snowpack has yet to melt.
An unusually wet winter brought unprecedented snowfall and a succession of heavy rainstorms, pulling much of the state out of a punishing years-long drought and transforming the year’s water outlook.
Molly White, Water Operations Manager for the State Water Project at the California Department of Water Resources, said atmospheric river storms have to led to near-record snowpack in many parts of the Sierra Nevada and reservoir storage is above average for this time of year.
Following three consecutive years of drought in California, the Sierra Nevada snowpack is one of the most bountiful in more than 40 years. While the snowpack and snow water equivalent is great news for water supply, there are concerns the record snowpack could create flooding issues.
The California Department of Water Resources electronic readings from 130 snow sensors placed throughout the state indicate the statewide Sierra Nevada snowpack’s snow water equivalent is 61.1 inches, or 237% of average for April 3. The snow water equivalent measures the amount of water contained in the snowpack and is a key component of DWR’s water supply forecast.
“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." – DWR Director Karla Nemeth pic.twitter.com/B8qvEg0Dg1
— CA – DWR (@CA_DWR) April 3, 2023
This year’s April result from the statewide snow sensor network is higher than any other reading since the snow sensor network was established in the mid-1980s. Before the network was established, the 1983 April 1 statewide summary from manual snow course measurements was 227% of average. The 1952 April 1 statewide summary for snow course measurements was 237% of average.
“This year’s severe storms and flooding is the latest example that California’s climate is becoming more extreme,” said DWR Director Karla Nemeth after the April 3 snow survey at Phillips Station in the Sierra Nevada. Photo: Fred Greaves/California DWR
“This year’s severe storms and flooding is the latest example that California’s climate is becoming more extreme,” said DWR Director Karla Nemeth. “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.”
Just as the drought years demonstrated that California’s water system is facing new climate challenges, this year is showing how the state’s flood infrastructure will continue to face climate-driven challenges for moving and storing as much of these flood water as possible.
“This year’s result will go down as one of the largest snowpack years on record in California,” said Sean de Guzman, manager of DWR’s Snow Surveys and Water Supply Forecasting Unit. (R-to-L: de Guzman, Jacob Kollen, Water Resources Engineer in Snow Surveys and Water Supply Forecasting Unit, and Jordan Thoennes, Water Resources Engineer in Snow Surveys and Water Supply Forecasting Unit.) Photo: Kenneth James/California DWR
“This year’s result will go down as one of the largest snowpack years on record in California,” said Sean de Guzman, manager of DWR’s Snow Surveys and Water Supply Forecasting Unit. “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.”
“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 #SnowSurveys and Water Supply Forecasting Unit. pic.twitter.com/X1Tj3eHqer
— CA – DWR (@CA_DWR) April 3, 2023
For California’s snow course measurements, only 1952, 1969 and 1983 recorded statewide results above 200% of the April 1 average. While above average across the state this year, snowpack varies considerably by region. 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.
The size and distribution of this year’s snowpack is also posing severe flood risk to areas of the state, especially the Southern San Joaquin Valley. 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.
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.
The storms #California has experienced this year have led to one of the largest #snowpacks on record. While these winter storms have helped the snowpack and reservoirs, we’re preparing with local agencies for the upcoming Spring snowmelt season. pic.twitter.com/RwJ6yTYvuR
— CA – DWR (@CA_DWR) April 3, 2023
Storms this year have caused impacts across the state including flooding in the community of Pajaro and communities in Sacramento, Tulare, and Merced counties. The 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 muscle wall, across the state since January.
On March 24, DWR announced an increase in the forecasted State Water Project deliveries to 75%, up from 35% announced in February, due to the improvement in the state’s water supplies. Governor Gavin Newsom has rolled back some drought emergency provisions that are no longer needed due to improved water conditions, while maintaining other measures that continue building up long-term water resilience and that support regions and communities still facing water supply challenges.
While winter storms have helped the snowpack and reservoirs, groundwater basins are 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.
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. The San Diego County Water Authority and its 24 member agencies provide rebates and programs to encourage water conservation.
Given the size of this year’s snowpack with more snow in the forecast, DWR anticipates conducting a May snow survey at Phillips Station. That is tentatively scheduled for May 1.
The California Department of Water Resources is using the winter storms to claim that the proposed Delta Conveyance project would help ensure a more reliable water supply for the State Water Project in light of how climate change will alter seasonal patterns of rain and drought.
In reality, the benefits of the conveyance project are speculative at best.
As the rain year continues to look promising, rice farmers are happy to expect most if not all of their water allocations will be delivered.
This week the Department of Water Resources announced a 75% water allocation to the irrigation districts served by the State Water Project.
Mandatory water restrictions are being lifted for nearly 7 million people across Southern California following winter storms that have boosted reservoirs and eased the severe shortage that emerged during the state’s driest three-year period on record.
Citing improvements in available supplies, the board of the Metropolitan Water District of Southern California has decided to end an emergency conservation mandate for agencies in Los Angeles, Ventura and San Bernardino counties that rely on water from the State Water Project.
It’s an arcane system of water law that dates back to the birth of California — an era when 49ers used sluice boxes and water cannons to scour gold from Sierra Nevada foothills and when the state government promoted the extermination of Native people to make way for white settlers.
Today, this antiquated system of water rights still governs the use of the state’s supplies, but it is now drawing scrutiny like never before.
As California braced for yet another round of winter storms Wednesday, state water officials announced that they were again boosting supplies for water agencies that serve 27 million residents.
The Department of Water Resources said it now expects to deliver 35% of requested water supplies — up from the 30% announced last month — via the State Water Project.
California’s water board decided Tuesday to temporarily allow more storage in Central Valley reservoirs, waiving state rules that require water to be released to protect salmon and other endangered fish.
The waiver means more water can be sent to the cities and growers that receive supplies from the San Joaquin-Sacramento Delta through the State Water Project and the federal Central Valley Project. The state aqueduct delivers water to 27 million people, mostly in Southern California, and 750,000 acres of farmland, while the Central Valley Project mostly serves farms.
