Greatest Risks Seen in 14 States: AZ, AR, CA, CO, FL, ID, KS, MS, MT, NE, NV, NM, OK and TX;WASHINGTON (July 20, 2010) -- More than 1,100 U.S. counties -- a full one-third of all counties in the lower 48 states -- now face higher risks of water shortages by mid-century as the result of global warming, and more than 400 of these counties will be at extremely high risk for water shortages, based on estimates from a new report by Tetra Tech for the Natural Resources Defense Council (NRDC).