Over half of the world's reservoirs will be "functionally dead"—more than 50% full of dirt—by 2060 due to sediment build-up, a new study predicts. Analyzing 550,000+ dams, researchers found we lose 7% of freshwater storage capacity per decade, threatening water supplies for 2 billion people.

Over half of the world's reservoirs will be "functionally dead"—more than 50% full of dirt—by 2060 due to sediment build-up, a new study predicts. Analyzing 550,000+ dams, researchers found we lose 7% of freshwater storage capacity per decade, threatening water supplies for 2 billion people.