Lately, it seems like severe storms and floods are becoming more common. Nationally, FEMA has designated 221,000 square miles as flood zones. For reference, 221,000 square miles is about the same size as Nevada and Arizona combined. It’s important to note that FEMA has five different levels of flood risk that it uses to classify the regions it studies. For example, some areas are predicted to have a 25% chance of flooding in the next 30 years, while others are only likely to flood every 100 years.
If you’re wondering which parts of the country are most affected by flooding, you’re in the right place. Here are the 5 states with the largest flood zones based on the percentage of homes that could be impacted by adverse weather.
1. Louisiana
FEMA has labeled 26,826 square miles within Louisiana as special flood hazard areas, amounting to a whopping 51% of the total land area of the state. Unfortunately, this means that 32% of homes in Louisiana are built in areas with at least a minor risk of flooding. Louisiana is especially vulnerable to flooding due to the state’s low elevation and proximity to the Gulf Coast. Since 2000, there have been many floods, including Hurricane Katrina in 2005 and the Mississippi River flood of 2011.
2. Florida
Florida’s flood zones cover nearly 8,000 square miles and contain 14.9% of the state’s homes. In terms of land area, Florida has significantly smaller flood zones than Louisiana. However, many homes are still at risk due to the state’s high population density. About 1.4 million households could potentially be in harm’s way during powerful storms.
Like Louisiana, Florida’s low elevation (topping out at only 345 feet) and risk of coastal storms combine to make flooding likely. The long stretches of picturesque beaches that attract residents to the state also put many of them in jeopardy during adverse weather events.
3. West Virginia
While you may expect the largest risk of floods to occur along the coasts, West Virginia occupies the third spot on our list. About 13.9% of homes in the state are in federally designated flood zones. Approximately 3,341 square miles could be affected by floods. West Virginia is known for its rolling hills, which seem like they should prevent water from pooling. However, the inland streams and rivers can act like gutters and quickly fill up with rain runoff, contributing to flooding risk.
4. Hawaii
One in ten homes in Hawaii are at risk of flooding, with about 642 square miles labeled as a flood risk. Frequent storms and sea level rise, averaging about an inch every 4 years, puts the state in jeopardy. These factors are causing the islands to sink very slowly over time. While it will take millions of years for the islands to fully submerge, flood risk is still present. Some parts of Hawaii receive over 400 inches of rain per year and have steep volcanic formations, which can create the conditions for flash flooding.
5. Kentucky
Kentucky has a much smaller percentage of affected homes than the other states on our list. Only 5% of homes fall within the state’s approximately 2,020 square miles of flood zones. However, flooding continues to be the most frequent and expensive natural disaster in Kentucky. Like West Virginia, Kentucky’s steep hillsides and narrow valleys don’t leave many places for rain and runoff to go. The eastern half of the state also receives weather from the Gulf of Mexico, which adds some extra risk of severe storms.
Prepare For Floods No Matter Where You Live
Current flood zones are determined by the historical 100-year floodplain. But what happens when there’s a record-breaking storm that defies rainfall expectations? Researchers from North Carolina State University found that when climate change is taken into consideration, over a million square miles may face flooding risks—about 4.5 times more land than is currently labeled as a flood zone by FEMA.
Homes in flood zones are required to have flood insurance, but households outside of flood boundaries may want to consider purchasing this form of protection. After all, 99% of U.S. counties have experienced a flood since 1998, so it’s probably better to be safe than sorry. It’s also a good idea to make a natural disaster preparedness plan and keep emergency supplies on hand just in case.