An artist’s rendering of the twin satellites of NASA’s Gravity Recovery and Climate Experiment (GRACE). Using data from this mission, scientists have determined that a vast volume of groundwater has been depleted from the Colorado River Basin over the last decade. Credit: NASA/JPL
The white “bathtub ring” of mineral deposits marks the decline of Lake Mead, which is able to store two years of the Colorado River’s historic annual flow. It currently holds only 9 months worth of that flow. Photo courtesy of US Bureau of Reclamation.