Underground stores of water in the southwestern United States have receded dramatically amid ongoing drought that has parched states from Oklahoma to the Pacific Coast and is costing California billions in lost crops and jobs, a new study shows. The study, based on NASA satellite data and released Thursday by the University of California, Irvine, shows that groundwater in the Colorado River basin has dropped by 40 million acre-feet over the past five years, the equivalent of two of the nation's largest reservoirs. "If drought conditions like this continue, there is a possibility we will entirely deplete our groundwater storage," said researcher Stephanie Castle, the report's author.
The data comes as policymakers are wrestling over how to manage the use of groundwater, accessed via wells and often the last resort for farmers unable to buy water from reservoirs in dry years. Most of the reduction was in Arizona, Castle said. In bone-dry California, the reservoirs that millions rely on for their water have also become depleted in the drought, new data from state water officials showed Thursday.