Nature: Because of a 14-year drought, demand for water by communities in the Colorado River Basin may soon exceed supply. To keep reservoirs filled and crops irrigated, people have been pulling water in unprecedented amounts from reserves underground. According to data from the Gravity Recovery and Climate Experiment (GRACE) satellite mission, which can measure the mass of water over the entire region, some 50 trillion liters of groundwater has disappeared. “It was way more than we ever thought,” says Jay Famiglietti of NASA’s Jet Propulsion Laboratory in Pasadena, California, and a coauthor of a study published in Geophysical Research Letters. The research team is now working to produce higher-resolution data to help better manage local water supplies.
