The findings could help more communities get a better handle on their flood risk and flood insurance needs, experts and authors of the study said. Flood insurance has become increasingly hard to get as some companies increase the price of policies or step back from insuring homes in certain markets due to more frequent and severe weather. That has left property owners more vulnerable. <\/p>\n
Experts told NBC News that with access to the right data sources, databases like the one described in the study could be developed nationwide.<\/p>\n
FEMA\u2019s maps are the main source nationally to identify flood-prone areas and what structures need to be insured. But experts say the system is outdated and has low resolution. The 100-year flood plain projection doesn\u2019t paint a complete picture of what areas are likely to flood. And climate change has rendered previously authoritative weather and climate projections less reliable<\/a>, the authors noted. <\/p>\n The study\u2019s use of address-level data allowed the researchers to pinpoint specific buildings that had flooded more than once. That information could help property owners know whether they should be purchasing flood insurance even outside of FEMA\u2019s flood hazard zones, experts said. In the U.S., 99% of counties have flooded<\/a> at least once but only 4% of homeowners have flood insurance, according to FEMA.<\/p>\n \u201cMore information about where it has flooded in the past could help people make different decisions,\u201d said Helena Margaret Garcia, the lead author of the study and a doctoral student at the University of North Carolina-Chapel Hill. <\/p>\n FEMA and the National Flood Insurance Program did not return requests for comment.<\/p>\n FEMA is currently in the process of redeveloping its flood mapping system, through an initiative called the Future of Flood Risk Data<\/a>, that it says will provide a more comprehensive look at flood hazards and risks in the country using more efficient, accurate and consistent technology.<\/p>\n As the planet warms, heavier rainfall is becoming more common because hotter air can hold more moisture, which later falls as rain. Climate change is also leading to a rise in global sea levels, which has made coastal and even some inland areas more vulnerable to flooding. Hurricane Helene, the third-deadliest hurricane of the modern era<\/a>, caused severe flooding in mountainous areas in the middle of North Carolina. Damage totaled more than $78 billion<\/a>, according to the National Oceanic and Atmospheric Administration.<\/p>\n Severe rainfall has caused flash floods to rip through towns across the U.S. in the last two weeks, most recently on Monday in New Jersey and New York City. Extreme floods resulted in at least six deaths in North Carolina<\/a> and more than 100 deaths in Texas<\/a>. Flash floods are the top storm-related killer in the U.S. resulting in an average of 125 deaths per year in the last few decades, according to the National Weather Service<\/p>\n![\"Water](\"https:\/\/www.newsbeep.com\/us\/wp-content\/uploads\/2025\/07\/250714-north-carolina-flooding-vl-300p-685320.jpg\")
Water markers on a home in Ocracoke, N.C., indicating by how much flooding increased between hurricanes over the years.Courtesy of Helena Garcia<\/p>\n
![\"The](\"https:\/\/www.newsbeep.com\/us\/wp-content\/uploads\/2025\/07\/250714-north-carolina-flooding-vl-259p-5b027b.jpg\")
The parking lot of the Eastgate Mall in Chapel Hill, N.C., on July 7, following a tropical storm.Antonia Sebastian \/ Courtesy of Helena Garcia<\/p>\n