Lady Bird Lake, a 416-acre reservoir in Austin, Texas, was built 60 years ago as a cooling pond for a power plant. It’s now a primary locus for recreation and flood control. By 2070, largely due to Texas’s strong economy and attractive big cities, the state will grow to 51 million, 22 million more people than today. The state’s demand for water, the State Water Board projects, will climb to 21.6 million acre-feet, up from 18.4 million. Photo © Brian Lehmann/Circle of Blue