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Mammoth Mountain received record snowfall in May 2019. Photo: Mammoth Mountain, Inc. California Reservoirs

Water Year 2020 Begins With Robust Reservoir Storage

Last winter was a bountiful one in terms of water supply for California, but it’s still too early to tell whether 2020 will be as generous.

The 2018-19 winter was one for the record books, with above-average precipitation. Snow continued to fall in late-spring, with several inches or more in the Sierra Nevada and the Southern California mountains.

Ski seasons were extended into May and June, delighting skiers and resort operators.

The snowfall, and a boost from late-season storms, increased the northern Sierra snowpack in May 2019, which was “atypical,” according to Alexi Schnell, water resources specialist with the San Diego County Water Authority.

The statewide Sierra Nevada snowpack was 164% of normal, with the northern Sierra at 172% of normal on May 23, 2019.

Major California Reservoirs Above Historical Average on November 8, 2019

Most major California reservoirs are above their historical averages as of November 8, 2019. (Graphic: California DWR)

Water Year 2020 begins with robust reservoir storage

The 2019 water year (October 1 – September 30) pushed snowpack levels well-above average and swelled major reservoirs to above-average. There were more than 30 atmospheric rivers, with many making landfall in Northern California. The state’s snowpack on April 1 was 175% of average.

The California Department of Water Resources said that makes a great start to 2020.

“We start the new water year in a good place,” said Karla Nemeth, director of the DWR. “However, we all know too well that California’s weather and precipitation are highly variable. What we have today could be gone tomorrow.”

Above average rainfall in San Diego

While the biggest gains in precipitation over the past year were in Northern California, the San Diego region also benefited. Water Year 2019 ended with the region at 125% of average rainfall at Lindbergh Field. The rainfall helped increase supplies in regional reservoirs.

Schnell cautioned that the climatological cycle in California can bring several consecutive years of drought, like the 2015-17 period, which prompted mandatory water-use reductions statewide.

Above-average temperatures in California in 2019

NOAA reported on November 6 that California experienced above-average to much-above-average temperatures from January through October 2019. The average U.S. temperature during that same period was 55.5°F, (0.5 of a degree above 20th-century average) “ranking in the warmest third of the record,” according to NOAA.

NOAA reported that California has had above-to much-above-average temperatures from January to October 2019.

NOAA reported that California has had above-to much-above-average temperatures from January to October 2019. (Graphic: NOAA)

Scripps Institution of Oceanography’s Center for Western Weather and Water Extremes, or CW3E, just released an analysis that calculated the odds of water year 2020 reaching 100% of water year normal precipitation totals. The odds range from 20 to 40% of the Southwest reaching 100% of water year normal precipitation.

Odds of reaching normal precipitation for Water Year 2020. (Graphic: CW3E, Scripps, UC San Diego)

National Weather Service seasonal outlook for precipitation

The three-month seasonal precipitation outlook for November-December-January by the National Weather Service Climate Prediction Center shows below-normal to normal precipitation in Central to Northern California and equal chances of below, near- or above-normal in southern California and much of the Southwest.

The November-December-January precipitation outlook from the National Weather Service.

The November-December-January precipitation outlook from the National Weather Service. (Graphic: NWS/NOAA)

“There will always be fluctuations based on weather and other factors, but the San Diego region continues to embrace water-use efficiency,” said Schnell. “The Water Authority and its 24 member agencies continue to increase San Diego County’s water supply reliability through supply diversification to provide a safe, reliable water supply to the region.”

An 800-Acre Reservoir Could Be Coming To Stanislaus County, But What Are The Risks?

A federal bill promising $14 million in funding for water storage projects for the Central Valley and Northern California served to place more attention on a proposed reservoir in Stanislaus County. Rep. Josh Harder, D-Turlock, got the millions included in a massive energy and water infrastructure bill in the House of Representatives. It includes $6 million for the Sites Reservoir near Colusa favored by agribusiness, $4.1 million for the North Valley Regional Recycled Water Program, $2.1 million for the Los Vaqueros Reservoir expansion in Contra Costa County, and $1.5 million for Del Puerto Canyon Reservoir near Patterson

San Diego Reservoirs Are Filling Up After A Record Year Of Rainfall

For the first time in a long time, the San Diego area is reaping the benefits of mother nature’s generosity. “We’ve had 9 inches of rain so far in February, it could be a record,” says Ron Mosher of the Sweetwater Authority. As a result, Sweetwater is sharing the wealth. All that water has been collecting in a series a lakes and reservoirs. “It’s been a blessing. We’re now transferring enough water to supply 130,000 people for six months,” says Mosher.

Water Transfer Between Reservoirs Set To Generate Cost Savings For South Bay Customers

The water gushed from a valve near the base of the Loveland Reservoir’s dam at 146,300 gallons per minute, cascading into the Sweetwater River below. The impressive sight near Alpine — which occurred, purposely, at 10:30 a.m. on Feb. 15 — marked the start of an ongoing transfer of water from the Loveland Reservoir to the Sweetwater Reservoir, where the water will be treated by the Sweetwater Authority and later supplied to the water agency’s customers in National City, Chula Vista and Bonita.

San Diego Reservoirs Fill up As More Rain And Snow Moves Into Region

Forecasters said Tuesday that California’s markedly wet winter will continue to deliver significant rain and copious high-elevation snow to the saturated San Diego area this week. From tomorrow afternoon through early Friday, another cold storm is expected to drop a half-inch to three-quarters of an inch of moisture along the coast, three-quarters of an inch to 1.5 inches in the inland valleys, 1.5 to two inches in the mountains, and 0.1 to 0.2 of an inch in the deserts, according to the National Weather Service.

USDA Announces $449 Million For Sites Reservoir

Congressman Doug LaMalfa (R-Richvale) issued the following statement after the U.S. Department of Agriculture announced a $449 million loan to Sites Reservoir Project Authority to build the interconnection facilities to move water in and out of Sites Reservoir. LaMalfa said: “Sites Reservoir is a project that I’ve been fighting to see completed since I’ve been in Congress. After many years of working with the USDA and my California colleague, Congressman John Garamendi, this newly acquired funding will allow the Sites project to finally take the next steps. I’ve said many times before – surface storage projects like this one are absolutely critical to securing the future of our state’s water supply.

Trump Officials Announce $450 million Loan For New California Reservoir Project

Trump administration officials were in California on Tuesday to announce a $450 million loan for the Sites Reservoir project in Colusa County. The money will be used to build a tunnel to carry water from the Glenn-Colusa Canal to an existing reservoir, giving farmers on the west side of the Sacramento Valley more access to irrigation water. The 12-foot diameter tunnel, called an intertie, will also be used to transport water to and from Sites Reservoir after it is built, said Jim Watson, general manager of the Sites Reservoir Authority.