NOVA · Season 52 · Episode 18

“Superfloods”

Aired Thursday 30 October 2025

In September 2024, Hurricane Helene dumped more than 14 inches of rain on North Carolina, triggering flash floods and mudslides, causing over $50 billion of damage, and killing more than 100 people. A shocked nation wondered how the city that bore the brunt of the destruction – Asheville, at 2,000 feet above sea level and more than 250 miles inland – could have suffered such a fate. With eyewitness testimony, dramatic unseen videos, drone flyovers, and 3D animations, NOVA pieces together a moment-by-moment account of the Asheville disaster. And it looks to other recent flash floods – including the devastating Fourth of July 2025 floods in the Texas Hill Country, and catastrophic flooding in Valencia, Spain – for lessons that might help prevent the next disaster. Are these violent floods becoming more frequent and ferocious? And what can communities do to protect themselves in the future?

S52 E18 discussion