Federal flood maps underestimated risk in areas hit hardest by Hurricane Helene [Video]

The federal government’s flood maps, which are used nationwide to signal areas vulnerable to inundation, vastly underestimated the flood risk faced by properties in the parts of North Carolina devastated by Hurricane Helene, according to data analyzed by The Washington Post.

The analysis of flood risk data from First Street, a climate modeling group, found that just 2 percent of properties in the mountainous counties of western North Carolina fall inside areas marked as having a special risk of flooding. That “Special Flood Hazard Area” designation, which compels homeowners to buy flood insurance if they want to get a federally-backed mortgage, indicates where the Federal Emergency Management Agency sees a risk of a 1-in-100-year flood. Scientists consider that zone, which amounts to a 1 percent chance of flooding in a given year, as facing significant danger.

In those mountainous areas, according to a Post analysis of First Street’s data, the …