A recent review of groundwater plans for the San Joaquin Valley indicates that the methods for achieving sustainable levels determined by the Sustainable Groundwater Management Act may not be feasible. The Public Policy Institute of California (PPIC) recently evaluated 36 Groundwater Sustainability Plans (GSP) from 11 critically over-drafted groundwater basins in the San Joaquin Valley and found that many plans overestimate the potential of expanding water supplies.
“They’re probably not realistic,” said Ellen Hanak, Director of PPIC’s Water Policy Center. “It’s very unlikely that they’re going to be able to make all these projects pencil out once you start looking at the exact sources of water that you’d be tapping.”
Ending overdraft and obtaining sustainability in the basins will rely on increasing water supplies through various projects and also managing demand and reducing water use. Of the groundwater plans that were studied, two-thirds of the proposed projects were addressing supply while less than a third were demand management projects. Hanak said that the development of GPS’s at a local level may not account for others in the area that may also be counting on the same water supply in their own plan.
“It’s understandable that folks have been focusing first on the supply piece because nobody likes the idea of land coming out of production,” said Hanak. “It would be worrisome if people weren’t looking at supply opportunities, but it’s also a little bit worrisome that people aren’t looking enough on the demand side.”
The basins that were evaluated have until 2040 to achieve sustainability. Hanak pointed out that while implementation is still in the early stages it allows for experimentation with different approaches. Pilot programs, groundwater trading, and other cooperative efforts present opportunities to develop more feasible strategies for groundwater sustainability.
“People can think about, what some of the collective infrastructure investments are that make sense to put money into,” Hanak noted. “I think if people aren’t able to collaborate and do some projects in a co-investment kind of way there’s going to be even less potential for supply enhancement.”