James Famiglietti, a leading hydrologist at the NASA Jet Propulsion Laboratory, wrote a recent article in Nature Climate Change entitled, “The global groundwater crisis”. In that article, he warns that, based on satellite imagery analysis, “most of the major aquifers in the world’s arid and semi-arid zones, are experiencing rapid rates of groundwater depletion.”
Worse, “nearly all of these aquifers underlie the word’s great agricultural regions and are primarily responsible for their high productivity.
“These water-deficient agricultural regions include California which, based on satellite image data, has less than one year of water remaining :
“Data from NASA satellites show that the total amount of water stored in the Sacramento and San Joaquin river basins – that is, all of the snow, river and reservoir water, water in soils and groundwater combined – was 34 million acre-feet below normal in 2014. That loss is nearly 1.5 times the capacity of Lake Mead, America’s largest reservoir.
“California been dropping more than 12 million acre-feet of total water yearly since 2011. Roughly two-thirds of these losses are attributable to groundwater pumping for agricultural irrigation in the Central Valley. Farmers have little choice but to pump more groundwater during droughts, especially when their surface water allocations have been slashed 80% to 100%. But these pumping rates are excessive and unsustainable.
“California has only about one year of water supply left in its reservoirs, and our strategic backup supply, groundwater, is rapidly disappearing.
There is no contingency plan.