‘Megadrought’ persists in western U.S., as another extremely dry year develops The long-running dry stretch rivals anything in the last 1200 years, a sign of climate-change induced "aridification." ByAlejandra Borunda Email Water levels usually peak in May at Folsom Lake in California, rising as Sierra Nevada snowpack melts away and courses down to the reservoir, near Sacramento. But this year, the drought that has gripped much of the U.S. West is already so strong that the lake is only half as full as normal. Instead of water, fields of purple lupines line vast swaths of dry lakebed. Folsom Lake’s situation is emblematic of the deepening drought across the western United States. As of May 6, 67 percent of the region was in a state of “severe” drought or worse; a stunning 21 percent is already in “exceptional” drought, the worst category in the U.S. Drought Monitor’s framework. At Lake Mead, one of the two major reservoirs of the Colorado River, which some 40 million Americans depend on, water levels are creeping toward a threshold that would trigger the first official shortage declaration for the basin.