"As flooding hammered Appalachia in the aftermath of Hurricane Helene, residents became intimately familiar with a new norm in the US’s post-storm script: dams at imminent risk of failing.

Officials last week said multiple dams were on the brink, including Tennessee’s Nolichucky Dam and North Carolina’s Walters and Lake Lure dams. People in nearby communities were ordered to evacuate.

Ultimately, the dams held. But the close calls highlighted the stress on the nation’s dams, many of which are more than half a century old and none of which were designed for the higher levels of precipitation brought on by climate change.

A lot of the dams “are absolutely performing a useful function for communities, whether helping to hold the water for irrigation or hydropower,” said Tom Kiernan, president and chief executive officer of American Rivers, an environmental nonprofit. But many others, he said, “are outdated, unsafe, abandoned.”"

Kendra Pierre-Louis and Leslie Kaufman report for Bloomberg October 3, 2024. [2]