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Event focuses on future supply of groundwater

Issue Date: May 14, 2014
By Cecilia Parsons

A variety of efforts have been undertaken to understand more about groundwater supplies in the San Joaquin Valley and of how to assure sustainable use of the resource, according to speakers at a conference in Clovis last week.

The 2014 Water Technology Conference, sponsored by the International Center for Water Technology—a public-private partnership based at Fresno State University—focused on groundwater. The resource has come under additional pressure this year due to shortages of surface water caused by three consecutive dry years.

Presenters at the conference highlighted projects undertaken to help in learning more about the forces affecting groundwater supplies.

For example, the Tulare Lake bed has been the site of a research project aimed at forecasting Sierra runoff. Once the largest freshwater lake west of the Rockies, the lake's sediment now holds a history of rainfall and drought. Sediment deposits created during thousands of years tell the story about annual runoff, said Rob Negrini, a geologist at California State University, Bakersfield.

Models derived from study of lake deposits show discharge from southern Sierra streams was strongly associated with surface temperatures in the Pacific Ocean, Negrini said. Sea surface temperature changes of only a few degrees upward have translated to greater than 8 million acre-feet of water in the San Joaquin Valley alone, he said.

Cal State Bakersfield mathematician Eduardo Montoya described another study of Sierra snowpack and water content, aimed at developing mathematical models for forecasting runoff.

Economist Tom Tomich of the University of California, Davis, discussed climate, water and food supply and their implications for the Central Valley. Climate patterns help researchers understand in a scientific way what is occurring, Tomich said. Speaking from a global perspective, he said the certainties are that population growth will continue and competition for fresh water supplies will intensify.

Models of Sierra runoff and snowpack show how to be better prepared and manage water supplies, he said.

Tomich said he has two sources of optimism for California agriculture: increasing demand for California crops and a dynamic agricultural sector where growers continue to find ways to compete in the marketplace.

"If society figures out how to manage systems—water, soil, pollinators—we'll be fine," Tomich said.

Groundwater, hydrogeologist Andrew Stone said, is the last resort for water supply globally. Stone, from New Hampshire-based American Ground Water Trust, suggested two other sources of water be tapped in order to recharge groundwater: desalination plants and re-use of water.

"There is no such thing as wastewater," he said. "It can be re-used. There are strategies for recovering and re-using water, but they will cost users."

Groundwater users also must understand what is happening beneath the land, Stone said, noting that diminished groundwater could be due to an inefficient pump, a dry well or a depleted aquifer.

Sharing insight on the California Water Plan, Kamyar Guivetchi of the state Department of Water Resources said it is the first plan done with input from three other state agencies: the Department of Conservation, the state Environmental Protection Agency and the Department of Food and Agriculture.

Three main themes of the updated water plan, he said, are: integrated water management to reduce conflicts among agencies; alignment of state, federal and local policy; and investment in innovation and infrastructure.

Climate change, Guivetchi said, will dramatically alter how water is managed in California. Implementing some of the regional management strategies will also come at a high cost. Strategies offered for the Tulare Lake basin, including conservation, recycling, groundwater banking, recovery of groundwater levels and restoring ecosystem flows, could cost $550 million through 2050.

Bill Phillimore, executive vice president of Paramount Farming Co. and keynote speaker at the conference, said farmers need to be active in assuring that groundwater supplies remain sustainable.

In the meantime, Phillimore said, more land will come out of production due to lack of irrigation water.

"I hope the inferior ground comes out first, rather than productive ground. That doesn't always happen and we need to be clever about that," he said.

David Zoldoske, director of the International Center for Water Technology, said strong leadership from the agricultural sector in water management decisions will be necessary in the San Joaquin Valley.

(Cecilia Parsons is a reporter in Ducor. She may be contacted at

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

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