Western Drought Colorado River

FILE - An aerial photo, morning light reflects off water in the All-American Canal near Calexico, Calif., on May 1, 2015. Colorado River water is diverted near Yuma, Ariz., to an 82-mile canal that runs west along the Mexican border and then north into 1,700 miles of gated dirt and concrete channels that crisscross farms. When gates open, water floods fields and gravity carries increasingly salty runoff downhill through the New and Alamo rivers to the Salton Sea. Prolonged drought, climate change and overuse are jeopardizing the water supply that more than 40 million people rely on. States are acknowledging that painful cuts are needed, but also stubbornly clinging to the water they were allocated a century ago. (AP Photo/Gregory Bull, File)