Reservoir lost 27.8m acre-feet of groundwater in 20 years, Nasa study finds, vanishing \u2018twice as fast as surface water\u2019<\/p>\n\n\n\n
The Colorado<\/a> River basin has lost 27.8m acre-feet of groundwater in the past 20 years, an amount of water nearly equivalent to the full capacity of Lake Mead, the largest reservoir in the United States, a new study has found.<\/p>\n\n\n\n The research findings, based on Nasa satellite imagery from across the south-west, highlight the scale of the ongoing water crisis in the region, as both groundwater and surface water are being severely depleted.<\/p>\n\n\n\n \u201cGroundwater is disappearing 2.4 times faster than the surface water,\u201d said Jay Famiglietti, a hydrologist at Arizona<\/a> State University and the study\u2019s senior author.<\/p>\n\n\n\n \u201cEveryone in the US should be worried about it, because we grow a lot of food in the Colorado River basin, and that\u2019s food that\u2019s used all over the entire country,\u201d he added. \u201cThese days, we\u2019re also supporting a number of data centers and computer chip manufacturers, and these are essential to our economy.\u201d<\/p>\n\n\n\n The Colorado River basin provides water to approximately 40 million people across seven US states, as well as to millions of acres of farmland. Most of the groundwater losses since 2003 occurred in the Lower Colorado River basin, including Arizona, Nevada and California, the study found.<\/p>\n\n\n\n The decreasing availability of surface water is easy to visualize across the west. There are the stark photographs of the dropping levels of water in Lake Powell and Lake Mead, and images of the Colorado River, whose flow has decreased approximately 20% in the past century.<\/p>\n\n\n\n But groundwater is different, Famiglietti said: \u201cIt\u2019s invisible. It\u2019s mysterious. The average citizen doesn\u2019t really understand it.\u201d<\/p>\n\n\n\n