Eleven trillion gallons — that’s the amount of water that NASA scientists say would be needed to replenish key California river basins in what they’re calling the first-ever estimate of the water necessary to end an episode of drought. That 11 trillion gallons is the deficit in normal seasonal levels that NASA said a team found earlier this year in the Sacramento and San Joaquin river basins, using Gravity Recovery and Climate Experiment (GRACE) satellites. The GRACE data, presented Tuesday at the American Geophysical Union meeting in San Francisco, showed those river basins losing about 4 trillion gallons per year — more than state residents use annually, NASA said.

In another finding, NASA said airborne measuring indicates the Sierra Nevada range snowpack was half previous estimates. "The 2014 snowpack was one of the three lowest on record and the worst since 1977, when California's population was half what it is now," Airborne Snow Observatory principal investigator Tom Painter of the Jet Propulsion Laboratory said in the NASA release.

California has been blasted by autumn storms dumping inches of much-needed rain – but that’s still not enough to get the Golden State out of its drought. “Recent rains are no reason to let up on our conservation efforts,” Felicia Marcus, chair of the State Water Resources Control Board, said recently.

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Analysis: 11 trillion gallons of water needed to replenish California drought losses: http://t.co/k32OealMnq #AGU14 pic.twitter.com/RHYuw826On — NASA (@NASA) December 16, 2014

— Gil Aegerter