A worker walks through farm fields in Los Banos
A worker walks through farm fields in Los Banos, California, United States, May 5, 2015. California water regulators on Tuesday adopted the state's first rules for mandatory cutbacks in urban water use as the region's catastrophic drought enters its fourth year. Urban users will be hardest hit, even though they account for only 20 percent of state water consumption, while the state's massive agricultural sector, which the Public Policy Institute of California says uses 80 percent of human-related consumption, has been exempted. REUTERS/Lucy Nicholson TPX IMAGES OF THE DAY