California’s approval of a $7.5 billion water bond has bolstered prospects for expanding reservoirs and groundwater storage, but the drought-prone state can effectively use no more than a 15 percent increase in surface water storage capacity because of a lack of water to fill it, according to a new analysis.
The Nov. 20 report by water engineers and scientists with UC Davis, The Nature Conservancy and three prominent water consultants, said California could potentially use up to 6 million acre-feet in combined additional surface and groundwater storage – about a third more capacity than Shasta Reservoir. Exceeding this expansion runs into limits of available precipitation and the ability to transport water.
“Reservoir storage does not equate to water supply,” said Jay Lund, lead author of the report and director of the UC Davis Center for Watershed Sciences. “Reservoirs cannot supply water without a water supply to fill them first.”