Floodplain Development Largely Concentrated in Gulf Coast States

New research published in the journal Earth’s Future shows that the United States is building fewer structures in floodplains, bucking conventional wisdom that development is running rampant in flood-prone areas, writes Jake Bittle in Grist. A separate paper found that some of the most effective approaches to limiting floodplain development are “routine municipal practices” such as zoning and permitting. 

The results reveal that floodplain development is not the intractable problem some have made it out to be. “Developers have built 844,000 units of housing on 2.1 million acres of floodplain — but if they had chosen available parcels at random, they would have built even more than that. This was true for more than 75 percent of all jurisdictions studied, indicating that most governments make at least some substantive attempt to avoid coastlines and riverbanks.”

According to the study, “Indeed, in the 21st century most towns and cities in the U.S. built very little or not at all in flood-prone areas. The vast majority of floodplain construction — the kind that grabs headlines and feeds the pessimistic narrative — has taken place in just two states: Louisiana and Florida.” 

Around half of properties that have filed multiple flood insurance claims are in Gulf of Mexico states. “The authors argue that these places need targeted intervention. The state or federal government could provide subsidies to encourage less risky construction, helping offset the economic lure of waterfront construction, or a state could just impose penalties on cities that allow for new builds near the water.”