Nearly twice as many homes face a substantial risk of flooding than the number in earlier government predictions, according to new study.
The study from the First Street Foundation estimates some 14.6 million properties around the country are at risk, with nearly 6 million people “currently unaware of or underestimating the risk they face.”
The Federal Emergency Management Agency (FEMA), by comparison, estimates just 8.7 million properties are at risk of a 100-year flood.
The new study, the first of its kind, pulls federal elevation and rainfall data along with flood claims and historic flood paths in an effort to offer a more robust picture of where major flooding could occur. It’s more comprehensive than the analysis by FEMA, which has been criticized for not continuously updating its predictions.
The study maps new areas previously not analyzed by the government — an important feature as climate change increases the risk for extreme weather that could cause flooding.
Appalachia and much of the West, along with Washington, D.C., had some of the biggest gaps between the FEMA and First Street estimates.
“The results shed light on the unevenness in which changing environmental factors will impact regions of the country differently, and prove the need to incorporate more localized data at a property level in order to fully understand flood risk,” the study’s authors said.
The research could mark a significant shift in how flood risk is evaluated and how homeowners assess the potential for damage at their property.
The grimmer outlook might make it tougher to get mortgages on certain properties as banks increase down payments required on homes that are more at risk of flooding.
It could also mean more property owners have to take on more robust and expensive flood insurance.