Can California Groundwater be Sustainably Managed with Agricultural Water Transfers? Effects on Aquifer Declines, Energy, and Food Production
California State University, Chico
California recently passed the Sustainable Groundwater Management Act, which requires that groundwater users develop sustainable groundwater management plans. However, California imports more water than any other place on Earth and is the largest producer of food in the USA. This creates competition between the “sustainable” uses of groundwater. Furthermore, recent droughts place even more pressure on water supplies (2013 was identified as the driest calendar year in California’s records). The ability to transfer water places pressure on northern California farmers to sell/lease their water, and decrease production and/or increase groundwater pumping to offset these transfers; however, the impacts of these transfers on regional economies and aquifer levels are often poorly understood. This work examines the effects of water transfers from northern California by using the United States Geological Survey’s Central Valley Hydrologic Model (CVHM) to simulate groundwater pumping scenarios corresponding to water transfers. The CVHM allows analysis of the spatial and temporal effects of pumping on the groundwater levels which are used to estimate: (1) the impact of additional groundwater pumping on aquifer levels, (2) the energy costs associated with additional lift due to aquifer declines throughout the region, and (3) the impacts associated with land fallowing for surface water transfers.