World’s large dams could lose quarter of capacity by 2050, says UN

Study suggests the thousands of dams clogged with sediment pose a threat to water supplies

Thousands of the world’s large dams are so clogged with sediment that they risk losing more than a quarter of their storage capacity by 2050, UN researchers have concluded, warning of the threat to water security.

A new study from the UN University’s Institute for Water, Environment and Health found that, by mid-century, dams and reservoirs will lose about 1.65tr cubic metres of water storage capacity to sediment.