Floodplain Development Largely Concentrated in Gulf Coast States

Many U.S. cities use ‘routine’ practices like zoning changes and permitting to discourage development in high-risk flood zones.

2 minute read

September 24, 2024, 9:00 AM PDT

By Diana Ionescu @aworkoffiction


Two small wood homes with floodwaters in coastal Louisiana after Hurricane Ida.

Flooding in the aftermath of Hurricane Ida in 2021. | ATexanLife / Adobe Stock

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.”

Thursday, September 19, 2024 in Grist

Young Professional

I love the variety of courses, many practical, and all richly illustrated. They have inspired many ideas that I've applied in practice, and in my own teaching. Mary G., Urban and Environmental Planner

I love the variety of courses, many practical, and all richly illustrated. They have inspired many ideas that I've applied in practice, and in my own teaching.

Mary G., Urban and Environmental Planner

Get top-rated, practical training for planners

Overlapping highways

The state-sanctioned urbicide of Austin

People don’t kill cities. Freeways do.

September 8, 2026 - Benjamin Schneider

The Hoover Dam blocking the Colorado River. The river's water level is noticeably low. The cliffs surrounding the blue water are brown and jagged.

US to reduce Colorado River water deliveries to Mexico

A new Colorado Treaty amendment reduces Mexico’s Colorado River water allocation by 250,000 acre feet.

September 11, 2026 - The Arizona Republic

Skyscrapers in Jersey City.

New Jersey’s second-largest city bans standalone data centers

Jersey City will continue to allow co-location facilities, such as those meant for research institutions that store their own data.

September 4, 2026 - The Cool Down

A New Jersey train approaches people waiting at the station.

Amtrak not solely to blame for New Jersey commuter rail's unreliability, report finds

A new study from the Garden State Initiative found that NJ Transit’s budget grew 20% across a 4 year period, but reliability declined significantly over the same period.

September 15 - Mass Transit

A tall, gray power plant billows smoke into a blue sky.

EPA erases limits on planet-warming pollution from power plants

Under Monday’s plan, power plants would still have some limits on how much mercury, arsenic and other contaminants they can emit.

September 15 - New York Times

A white RAPID bus. The lower half is light blue, and says RAPID in purple text. The bus is half visible, appearing from the left side of the image.

Phoenix announces new on-demand transit service, more frequent RAPID buses

Both new services will launch in October, and are part of Phoenix's Project Effective Access Solutions for Easing Congestion.

September 15 - KJZZ

FREE Course: Walkable City 1: Why Walkability?

After describing his path towards focusing on walkability as the essence of good planning, Jeff Speck marches through his five principal reasons for making more walkable places.

Reinventing Malls: Planning Alchemy—Turning Gray Fields Into Gold

The course focuses on the opportunities and imperatives that shape reinvention of mall sites.