Belatedly, state receives season’s first wet storms

Issue Date: December 4, 2019
By Christine Souza

Thankful for the season's first significant storms, California farmers say they appreciate that Mother Nature has finally come through with a good soaking of rain and snow to enhance the state's water supply.

Farmer Sal Parra Jr., assistant manager for Fresno-based Burford Ranch, called the arrival of winter weather very welcome.

"Although the rain is late, it is a good start to the water year because of where reservoir levels stand and the snow that is to come with these storms," said Parra, who grows commodities including almonds, winegrapes and row crops within the Westlands Water District. "The next two weeks show more storms coming in, so we are looking good."

Rains have come just in time, Parra said, to incorporate the postharvest fertilizer and soil amendment applications he has been doing, noting that the moisture will also activate the pre-emergent herbicides he has applied.

"The prolonged dry weather did allow us to get ahead in ground and bed prep for next year's crops, so we are ahead of schedule," he said.

Happy that the weather changed from 70-degree temperatures to a cooling trend with rain, Kern County almond farmer Jenny Holtermann said prior to the storms, "we had to apply a dormant spray to force our trees to lose their leaves and go dormant. They were enjoying the warm weather as much as we were."

California Farm Bureau Federation Senior Counsel Chris Scheuring said, "There is a first sigh of relief when the Pacific rolls its first storms of the water year onshore, but now the human challenges come in how we capture, manage and move that water to serve multiple values."

Californians, Scheuring said, "know that nothing is certain in any rain year, and it can all stop too soon or tip the other direction into a flood event."

Citing dry weather in October and November, the State Water Project announced an initial allocation of 10% for the coming year, noting that it would update the allocation depending on this winter's rain and snow.

Despite the slow start to the water year, which officially began Oct. 1, officials from the California Department of Water Resources reported the recent cold-weather storms packed a punch throughout the state, with additional storms anticipated in coming weeks.

"A trough between the pressure systems allowed these systems to come through the cold weather up north and pick up some rain and bring it onshore, so during Thanksgiving week we got pretty good systems impacting both Northern and Southern California," DWR spokesman Chris Orrock said. "Between the two systems, we got snow down to the 3,000- to 5,000-foot levels."

This year's weather is similar to what happened last year, he said, when the state didn't have significant rain until after Thanksgiving.

"Last year, we didn't have that much rain or snow until the end of December and then we had the fifth-highest recorded snowpack in history," Orrock said, adding that the snowpack represents one-third of the state's water storage.

Noting that much of the state's precipitation happens between late December and early February, Orrock said, "In California, the majority of the rain we get is brought in by atmospheric rivers (narrow corridors of concentrated moisture in the atmosphere), so one or two atmospheric rivers will really change the totals for the season."

Plentiful rain and snow that accumulated the past two years sets things up well for this water year, he said, adding, "For the most part, our major reservoirs are at or above historical average for this time of year."

At the beginning of this week, Shasta Reservoir north of Redding, the largest federal Central Valley Project reservoir, was at 71% of its 4.5 million acre-foot capacity—or 119% of average—according to DWR. Lake Oroville in Butte County, the principal reservoir for the State Water Project, was at 54% of its 3.5 million acre-foot capacity, 90% of average. Orrock said Lake Oroville has been managed at a lower capacity as the agency finalizes spillway-related construction. San Luis Reservoir, a south-of-delta reservoir shared by the CVP and SWP, stood at 43% of its 2 million-acre-foot capacity—72% of average—but most of the other large reservoirs remained at above-average levels.

"Because we had good storage last year and built that storage up, even if we do have a dry year this year, which we hope we don't, but if we do, we have storage in place to withstand that," Orrock said. "If we get into two or three years of dry, that's different."

In addition to snowpack and surface storage in state and federal reservoirs, storage of water in underground aquifers and ensuring the sustainability of that resource has taken added emphasis. The need to bring groundwater supplies into long-term balance under the Sustainable Groundwater Management Act has helped encourage a voluntary strategy that uses floodwater to replenish groundwater supplies, called Floodwater Managed Aquifer Recharge or Flood-MAR.

Flood-MAR has been around for many years, and now the state is looking at how to use floodwater most effectively to put water back into the ground, Orrock said, adding, "It's another tool in our tool belt that allows us, in conjunction with SGMA and other conservation methods, to start looking at the overall health of our water system and water storage in California."

DWR's first snow survey of the year is scheduled Jan. 2, when state water officials will manually measure the snowpack to help determine the amount of water that will ultimately melt and run off to reservoirs during warmer months.

(Christine Souza is an assistant editor of Ag Alert. She may be contacted at csouza@cfbf.com.)

Permission for use is granted, however, credit must be made to the California Farm Bureau Federation when reprinting this item.




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