A plan to address a shrinking supply of water on a river that serves 40 million people in the U.S. West is headed to President Donald Trump. The U.S. House and Senate approved the Colorado River drought contingency plan. Arizona, California, Colorado, Nevada, New Mexico, Utah and Wyoming spent years negotiating the drought plan. They aim to keep two key reservoirs from falling so low they cannot deliver water or produce hydropower.Mexico has promised to store water in Lake Mead on the Arizona-Nevada border if the U.S. legislation is approved by April 22.