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.
After years of punishing drought, a historic winter snowpack is bringing a reprieve to the Colorado River Basin and the nation’s largest reservoirs.
The US Bureau of Reclamation announced Thursday that this winter’s rain and the projected runoff from above-normal snowfall is expected to boost its water releases this year from Lake Powell to Lake Mead by 2.5 million acre-feet.
Water levels fell so low in key reservoirs during the depth of California’s drought that boat docks sat on dry, cracked land and cars drove into the center of what should have been Folsom Lake.
Those scenes are no more after a series of powerful storms dumped record amounts of rain and snow across California, replenishing reservoirs and bringing an end — mostly — to the state’s three-year drought.
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 record snowpack and snow water equivalent is great news for water supply, there are concerns the record snowpack could create flooding issues.
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 Bureau of Reclamation March 28, announced an increase in Central Valley Project 2023 water supply allocations. After below average precipitation in February, Reclamation announced a conservative initial water supply allocation for the CVP on Feb. 22. Additional atmospheric river systems have since boosted hydrological conditions and storage volumes, allowing for a more robust water supply allocation.
Since making initial allocations last month, Shasta Reservoir, the cornerstone of the Central Valley Project, has increased from 59% to 81%, and San Luis Reservoir, the largest reservoir south-of-Delta, from 64% to 97%. Record-breaking snowpack conditions currently exist in the Southern Sierra coupled with significant snowpack in the Central Sierra and Northern Sierra/Trinity.
The Bureau of Reclamation March 28, announced an increase in Central Valley Project 2023 water supply allocations. After below average precipitation in February, Reclamation announced a conservative initial water supply allocation for the CVP on Feb. 22. Additional atmospheric river systems have since boosted hydrological conditions and storage volumes, allowing for a more robust water supply allocation.
Since making initial allocations last month, Shasta Reservoir, the cornerstone of the Central Valley Project, has increased from 59% to 81%, and San Luis Reservoir, the largest reservoir south-of-Delta, from 64% to 97%. Record-breaking snowpack conditions currently exist in the Southern Sierra coupled with significant snowpack in the Central Sierra and Northern Sierra/Trinity.
Based on current hydrology and forecasting, Reclamation is announcing the following increases to CVP water supply allocations:
North-of-Delta Contractors
South-of-Delta Contractors
Friant Division Contractors
Friant Dam is currently being operated for flood control purposes; as long as these conditions exist contractors are able to take delivery of all available water from Friant Dam to the maximum extent of their respective contracts.
All other CVP water supply allocations remain the same as noted in the Feb. 22 announcement.
As the water year progresses, changes in hydrology, actions that impact operations, and opportunities to deliver additional water will influence future allocations. Reclamation will continue to monitor hydrology and may adjust basin-specific allocations if conditions warrant an update. Water supply updates and past year’s allocations are posted on Reclamation California-Great Basin Region’s website.
As another round of heavy storms battered California, Gov. Gavin Newsom announced Friday that he would ease state rules to allow local water agencies to more easily redirect floodwaters to replenish the state’s severely depleted groundwater supplies.
The move comes amid criticism that California has flushed trillions of gallons of water out to sea during this winter’s repeated deluges. Water agencies and experts say the state’s strict rules that limit who can take water from streams and creeks have prohibited the local agencies from capturing the excessive flows, though California desperately needs to bank water for its next drought.
With recent storm systems that swept through the west, California has seen more precipitation this year than normal, bringing the water supply stored in reservoirs — both locally and across the state — up from historic lows to levels that are some of the highest in years.
And with drought conditions having improved in much of California, experts say that the amount of water captured from this year’s particularly wet winter could help ease the impact of hotter, drier weather in San Diego, as the state recovers its depleted water supplies.
More than 9,000 California residents were under evacuation orders Friday as a new atmospheric river brought heavy rain, thunderstorms and strong winds, swelling rivers and creeks and flooding several major highways and small rural communities.
In Santa Cruz County, a creek bloated by rain destroyed a portion of Main Street in Soquel, a town of 10,000 people, isolating several neighborhoods. Crews were working to remove trees and other debris and find a way for people to cross the creek, county officials said.
The Water News Network is San Diego County’s source for water news and information.
