Over the last 50 years, the Colorado River has rarely reached its mouth in the Sea of Cortez. The giant dams on its main stem and the water demands of some 35 million people have largely dried out its vast delta, which once sustained cottonwood and willow forests and armies of fish and birds. But in November 2012, the U.S and Mexico signed Minute 319, a complex water-sharing agreement that includes an experimental flood to help jumpstart the Delta's ecosystem, to be followed by smaller releases of water to sustain new growth ("New Hope for the Delta," HCN, 10/28/13).
On March 23, officials opened the gates of Morelos Dam on the international border, and began the eight-week-long flood. Residents along the river's dry stretches came to splash in its renewed flow, which distributed tree seeds throughout the Delta and reached major restoration projects, just as scientists had hoped. It has yet to bee seen whether the water will reach the sea.