Florida Leads US in Residential Development of Floodplains

Half of all residential development on flood-prone land in the U.S. over the past two decades has been built in Florida.

From 2001 to 2019, more than 2 million acres of floodplains in the U.S. have been developed into over 840,000 new residential properties, according to a study conducted by the University of Miami Rosenstiel School of Marine, Atmospheric, and Earth Science.

In the Sunshine State, the development of floodplains into nearly 400,000 residential properties represented 21 percent of all new housing built in Florida, and the highest percentage of any state. Researchers expected to see a higher percentage of new Florida housing built in the floodplain, according to the report. Forty percent of Florida’s developable land is in floodplains.

South Florida alone accounted for 124,090 residential properties developed on 34,560 acres of floodplain land between 2001 and 2019, according to the report’s lead author, Ph.D. student Armen Agopian. Miami-Dade accounted for nearly 20,000 acres and 95,000 residential properties, while Broward saw 8,200 acres developed into 24,500 residential properties. About 6,500 acres of floodplain land in Palm Beach County were developed into more than 5,000 residential properties over the past two decades.

Construction in flood-prone areas, which includes land near bodies of water and low-lying land, increases the likelihood of more damaging floods in those areas. Scientists from the University of Miami defined floodplains as the Special Flood Hazard Areas where flood insurance is required, according to the study, which was published in the journal Earth’s Future.

Across the country, 74 percent of communities have limited new development in floodplains and 87 percent have restricted new housing in flood-prone areas through local regulations and practices, according to the report.

South Florida, the most densely populated region in the state, has a high concentration of floodplains. Nearly all of Miami Beach is located in or near a FEMA-designated Special Flood Hazard Area, for example.

Coastal communities are more likely to concentrate new development in floodplains compared to inland communities, according to the report. Waterfront real estate is more valuable, despite the growing risks associated with construction and potential damage from floods and hurricanes.

In fact, Florida is one the riskiest markets for property insurance companies and one of the most expensive for policyholders. The frequency and intensity of natural disasters has increased because of climate change.

The Miami Herald reported earlier this year that parts of South Florida are sinking, citing a Virginia Tech research paper that estimates Miami could have about 80,000 properties flooding by 2050. By 2100, sea levels could rise about six feet.