Risk analysis: FL among four states most threatened by climate-caused flooding

One-fourth of U.S. critical infrastructure at risk of flooding, study says

By: - October 19, 2021 1:45 pm

Sunny-day flooding caused by higher sea level along Brickell Avenue in downtown Miami. Credit: Wikimedia Commons

Florida is one of four states most at risk of severe damage due to flooding caused by climate change, and cities including Miami, St. Petersburg and Tampa are among the 20 U.S. cities most at risk, according to an analysis by the New York-based nonprofit research organization First Street Foundation.

“The highest concentration of community risk exists in Louisiana, Florida, Kentucky, and West Virginia, with 17 of the top 20 most at-risk counties in the U.S. (85 percent) residing in these four states,” according to the First Street analysis. “Louisiana alone accounts for six of the top 20 most at-risk counties (30 percent) and is home to the most at-risk county in the country, Cameron Parish.”

Cities at risk. Source: First Street Foundation

In Florida, the county most at risk by far is Monroe County, which includes the Florida Keys and part of the Florida Everglades. The top 10 most-threatened also include Charlotte, Lee and Collier counties on the southwest coast, Franklin, Wakulla, Gulf and Dixie counties in north Florida, and Miami-Dade and Broward counties in south Florida.

Monroe, Charlotte and Franklin counties are at highest risk of losses of residential properties, commercial properties and roads, the analysis says. Monroe, Charlotte and Dade face the greatest risks of infrastructure losses.

First Street is a 501(c)(3) organization whose advisory board includes professors and executives from entities such as Massachusetts Institute of Technology and the Wharton School at the University of Pennsylvania. Its research partners include Florida Atlantic University, Florida State University, University of Central Florida, University of Florida, and University of Miami.

The organization’s report, titled Third National Flood Risk Assessment: Infrastructure on the Brink, found that one-fourth of “critical” infrastructure in the United States is at risk of flooding and that the risk will worsen. That infrastructure includes utilities, airports, ports, hospitals, roads, schools, government buildings, commercial property and private property. It highlights flood risks for every city and county across the continental U.S. over the next 30 years.

Risk to Florida municipalities over the next 30 years. Source: First Street Foundation

“Changing environmental conditions are driving worsening flood events, with consequences for counties, cities, towns, and local communities,” the report says. “[Individuals and communities] are increasingly likely to find their local roads, businesses, critical infrastructure, utilities, or emergency services affected by flooding, indirectly threatening their quality of life, safety, and wellbeing.”

The report forecasts: “Over the next 30 years, due to the impacts of climate change, an additional 1.2 million residential properties, 66,000 commercial properties, 63,000 miles of roads, 6,100 pieces of social infrastructure and 2,000 pieces of critical infrastructure will also have flood risk that would render them inoperable, inaccessible, or impassable.”

Key findings:

+ Risk to residential properties nationally is expected to increase by 10 percent over the next 30 years, with 12.4 million properties at risk today (14 percent) and 13.6 million at risk of flooding in 2051 (16 percent).

+ Two million miles of road (25 percent) are at risk today, and that is expected to increase to 2.2 million miles of road over the next 30 years.

+ Commercial properties are expected to see a 7 percent increase in risk of flooding from 2021 to 2051, with 918,540 at risk today (20 percent) and 984,591 at risk of flooding in 30 years.

+ Nearly 36,000 critical infrastructure facilities are at risk today (25 percent), increasing to nearly 38,000 facilities by 2051. Compounding that risk, 71,717 pieces of social infrastructure facilities are at risk today (17%), increasing to 77,843 by 2051 (19% and an increase of 9% over that time period

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Laura Cassels
Laura Cassels

Laura Cassels is a reporter, former statehouse bureau chief, and former city editor. She is a classical pianist, a Florida State University graduate and proud alum of the Florida Flambeau, an independent college newspaper.