After two dry years, the California is in desperate need of rain and snow. October marks the beginning of California’s new water year, which will run through Sept. 30 next year.
This also signals the transition from the long, dry summer months to the wetter time of year. But new research is showing a delay to California’s rainy season.
With just one month left in the precipitation year and little rainfall to show for it, Turlock Irrigation District and its customers are currently experiencing the fourth-driest year on record.
According to TID hydrologist Olivia Cramer, the Tuolumne River Watershed has received just 18.23 inches of precipitation since Sept. 1, or just about half of the historical average. The TID precipitation year, which is different from the water year, runs from Sept. 1 through Aug. 31 and will come to an end next month. The water year runs from Oct. 1 through Sept. 30.
This year’s 18.23 inches of rainfall come as the region experiences a second-straight year of drought conditions and puts 2020-2021 in the record books as TID’s fourth-driest precipitation year on record. The three driest years on record in order are 1977 (10.90 inches), 1976 (17.46 inches) and 2015 (17.50 inches).
A disappointingly dry February is fanning fears of another severe drought in California, and cities and farms are bracing for problems. In many places, including parts of the Bay Area, water users are already being asked to cut back.
The South San Joaquin Irrigation District season is starting March 10 although board members added an asterisk to that decision. Restrictions on water allocation as the irrigation season unfolds loom as a possibility especially if March ends up being mostly dry. The board last week was guided by the conservative outlook the National Oceanic and Atmospheric Administration posted for its California and Nevada River Forecast that includes the Stanislaus River watershed that the SSJID relies on to make deliveries to farmers irrigating 52,000 acres around Manteca, Ripon, and Escalon as well as deliver drinking water to Manteca, Lathrop, and Tracy.
California’s wet season has not brought much relief so far and the outlook is not promising.
The water year, which runs from October through April, started off slowly. October was the second driest on record for California. Later, strong systems – including an atmospheric river in late January that caused flooding, debris flows and feet of snow in the Sierra – brought needed moisture to the Golden State.
The start of California’s annual rainy season has been pushed back from November to December, prolonging the state’s increasingly destructive wildfire season by nearly a month, according to new research. The study cannot confirm the shift is connected to climate change, but the results are consistent with climate models that predict drier autumns for California in a warming climate, according to the authors.
Yes, it’s been pretty dry so far this winter, but there is no need to worry. The major winter storm that roared through Southern California Monday proved we can erase a month’s worth of rain deficit in one day. I recently explained how the climate where we live — the Mediterranean Climate — sees the majority of its annual rainfall in the winter months. In fact, a whopping 80% of Southern California’s annual rain and snow falls from December through March.
A dry start to California’s water year is reflected in the season’s first snow survey of the Sierra Nevada snowpack. The statewide snowpack is 52% of average for Dec. 30. On average, the Sierra snowpack supplies about 30% of California’s water needs.
The California Department of Water Resources manual survey at Phillips Station recorded 30.5 inches of snow depth and a snow water equivalent of 10.5 inches, which is 93% of the January 1 average at that location, according to DWR officials. The snow water equivalent,or SWE, measures the amount of water contained in the snowpack and is a key component of DWR’s water supply forecast.
While the Phillips Station measurement was positive, DWR’s electronic readings from 130 stations placed throughout California show the statewide snowpack’s SWE is 5 inches, or 52% of the December 30 average.
“The snow survey results reflect California’s dry start to the water year and provide an important reminder that our state’s variable weather conditions are made more extreme by climate change,” said DWR Director Karla Nemeth. “We still have several months left to bring us up to average, but we should prepare now for extended dry conditions. The Department, along with other state agencies and local water districts, is prepared to support communities should conditions remain dry.”
“The first snowpack survey of the water year points to California’s climate variability, which is why a diverse water portfolio is needed to provide a reliable supply,” said Goldy Herbon, San Diego County Water Authority senior water resources specialist. “The Water Authority and its 24 member agencies have successfully diversified water sources, and continue to expand those sources, to ensure our supply meets the needs of the region’s 3.3 million people and its $245 billion economy.”
The supply sources include water from the Claude “Bud” Lewis Carlsbad Desalination Plant, where ten workers volunteered to live on-site in 2020 to keep the water flowing during the coronavirus pandemic.
When the Sierra Nevada snowpack melts, it feeds into rivers and is stored in reservoirs across California. Reservoirs are tapped as needed during the dry months. However, state officials again said that climate change is affecting California’s snowpack, as more precipitation falls as rain and less as snow. And they urged Californians to make water conservation a “way of life.”
“Today’s survey brought a first glimpse of how the state’s snowpack is shaping up, but there is a lot of winter still ahead,” said Sean de Guzman, chief of DWR’s Snow Surveys and Water Supply Forecasting Section. “While the dry conditions during late summer and fall have led to a below average snowpack, it is still encouraging to have the amount of snow we already have with two of the three typically wettest months still to come.”
DWR conducts five snow surveys at Phillips Station each winter near the first of each month, January through April and, if necessary, May. Guzman said the next survey is scheduled for February 2.
Sean De Guzman (R), chief of the California Department of Water Resources Snow Surveys and Water Supply Forecasting Section, and Jeremy Hill, DWR water resources engineer, conduct the first snow survey of the 2021 season at Phillips Station in the Sierra Nevada. Photo: Kelly M. Grow/DWR
So far this water year that began Oct. 1 has been treating most of Utah like a miserly scrooge, stingy with storms and the accompanying snow. The southern half of the state, as of Monday, was sitting in the 60% of normal accumulation of snowpack, and the Lower Sevier River Basin at 36% of normal is experiencing abysmally dry conditions.
It’s that time of the year in California, when water managers, climatologists and meteorologists look at the factors that determine what the winter will bring during Water Year 2020-21 (October 1, 2020 – September 30, 2021).
The National Oceanic and Atmospheric Administration recently said that La Niña conditions are present in the tropical Pacific, “with an approximately 85% chance of La Niña lasting through the winter.” Forecasters currently think this La Niña will be on the stronger side. For California, those conditions typically mean a drier winter, with increasingly dry conditions heading into 2021.
The Water News Network is San Diego County’s source for water news and information.
