Lake Powell, the second-largest reservoir in the United States, is currently at just 22% of its capacity—putting it roughly 8 percentage points away from levels

Lake Powell, the second-largest reservoir in the United States, is currently at just 22% of its capacity—putting it roughly 8 percentage points away from levels that could force Glen Canyon Dam to stop generating electricity. Lake Powell was created when Glen Canyon Dam was completed in 1963, flood…