Recent rain and snow improves federal water allotment

The rain and snow from December and January have raised reservoir and snowpack levels enough that the federal agency that supplies a large portion of Tracy’s water is optimistic that cities like Tracy can get most of the water they request in 2023.

Last week the U.S. Bureau of Reclamation reported that the Central Valley Project, including several federally-operated dams, will be able to deliver 75% of contracted amounts to municipal and industrial users like the city of Tracy and 35% of contracted amounts to farms south of the Sacramento-San Joaquin Delta.

Last year at this time the USBR, citing a third consecutive year of drought, informed municipal and industrial users that they would get just 25% of their contracted amounts, and farmers south of the Delta would get none of their contracted amounts.

While early January’s rains flooded farm fields south of Tracy, the runoff from the Sierra Nevada and foothills that would go into storage for use in the summer hasn’t filled reservoirs, and in many cases is still below the historical averages for reservoir storage.

That’s why Ernest Conant, Director of USBR’s California-Great Basin Region, said in a statement last week that the bureau is “cautiously optimistic,” considering that there is still a possibility that dry conditions could still set in this spring.

“We received a much-needed dose of rain and snow in December and January that helped boost the water levels at our CVP reservoirs. The projected runoff from the snowmelt later this year will further benefit the state as we head into the summer months,” Conant said. “However, we are all too aware of the precarious nature of recent weather patterns and must proceed prudently as we move through the water year—especially with below average storage in the state’s largest reservoir, Shasta.”

Just north of Redding, Shasta Reservoir was at 59% of capacity this week and at 93% of the historical average. New Melones Reservoir along the Stanislaus River, where Tracy gets much of its water, is at 44% of capacity and 77% of the historical average.

The Central Valley Project acts as the state’s plumbing system, with water from as far north as Shasta Reservoir moving through rivers and the Delta to the Jones Pumping Plant northwest of Tracy and into the Delta-Mendota Canal, which passes by the city’s water treatment plant on its way south toward the San Luis Reservoir on the western side of the San Joaquin Valley near Santa Nella.

The city has contracts to draw as much as 20,000 acre-feet per-year through the Delta Mendota Canal. Most of that water is subject to the 75% M&I restriction, and some, which the city receives under an agreement with West Side Irrigation District, is subject to the 35% agricultural restriction.

According to the city’s Urban Water Management Plan of 2020 the city’s annual demand for potable water is 19,527 acre-feet.

Much of the city’s other water supplies are more reliable because they’re based on water rights that were established more than a century ago.

The South County Water Supply Project, established in 2005 in a partnership with the South San Joaquin Irrigation District, draws water from the Stanislaus River, through Woodward Reservoir and the Nick C. DeGroot Water Treatment Plant in Oakdale, with a pipeline delivering 10,000 acre-feet per-year to Tracy.

Peter Reitkerk, general manager of South San Joaquin Irrigation District, said that the Central Valley Project restrictions don’t have a direct effect on SSJID, which draws its water from the river based on pre-1914 water rights.

“SSJID, because of our very reliable water supply, Tracy has been able to lean on that supply, especially in the last couple of years,” Reitkerk said, adding that the district has just missed having to impose restrictions on its customers in the last few years.

The district still must be mindful of water levels at New Melones. Under a 1988 agreement SSJID and Oakdale Irrigation District have rights to the first 600,000 acre-feet that flow into New Melones Reservoir each year. While flows in the Stanislaus River were less than that during the drought, Reitkerk said that the California-Nevada River Forecast Center expects over 1.8 million acre feet of inflow into New Melones this year.

“This year is certainly going to allow for us to have a full season. I can tell you that it’s very welcome, considering the last several years of drought. We need to replenish our reservoirs regionally and statewide and this is certainly helping to do that.”

David Weissenberger, general manager for the Banta-Carbona Irrigation District, said that Central Valley Project water is a supplemental and emergency water supply that the district uses to meet local farmers’ irrigation demands when those demands exceed the water available from the river.

“In 2023 the current river water supply coupled with the 35% CVP allocation is a huge improvement in the outlook for the 2023 irrigation season over the past two seasons,” he said.

Byron Bethany Irrigation District also uses a combination of CVP water and longstanding rights to draw water from Old River to serve its customers, including local farmland, plus the community of Mountain House. BBID also provides water, under a contract with the city of Tracy, for the Tracy Hills development.

• Contact Bob Brownne at brownne@tracypress.com, or call 209-830-4227.