At the start of World War I, a scientist named Eugene Clyde La Rue hiked the American West to estimate how much water flows down the Colorado River. His findings were ignored, but leaders today don't have to make the same mistake, says ÍÃ×ÓÏÈÉú´«Ã½ÎÄ»¯×÷Æ· hydrologist Shemin Ge.