Tampa is the second-most exposed city in the state, the disaster modeling found.
About 114,000 more Florida properties are at risk of flooding in a 100-year storm than the Federal Emergency Management Agency currently estimates, according to a model released Monday by a nonprofit arguing the country has undersold its vulnerability to disasters.
Tampa is the second-most exposed city in the state, says the First Street Foundation, with 43,111 properties that could flood in such an event — the seventh most at-risk in the country. No. 1 in the United States is Cape Coral, according to the analysis, with more than 90,000 at-risk properties.
The foundation’s flood tool is meant to highlight gaps in federal insurance maps and give home buyers what First Street promises is a better view of vulnerability. The data include property-specific reports that are accessible online for users to search their address — and will soon also be displayed on realtor.com, one of the largest real estate listing websites in the country, the company said.
First Street’s effort joins a growing body of research that tries to estimate how Florida’s already substantial flood risk could swell with sea-level rise. By 2050, the foundation predicts, one in three Pinellas County properties could be in a 100-year flood zone.
Matthew Eby, founder and executive director of Brooklyn-based First Street, said the aim is a “democratization” of data.
“It’ll finally allow homeowners, home buyers and renters to understand their risk and how it’ll change over time, so they can best protect what for a majority of Americans is their most valuable asset,” he said. The modeling was developed by dozens of hydrologists, researchers and data scientists from technology firms and universities.
Five Florida counties, according to First Street — Lee (1), Miami-Dade (3), Charlotte (5), Broward (7) and Palm Beach (8) — are in the top 10 in the country with the most properties at risk of flooding in a 100-year event. Hillsborough is 11th and Pinellas is 12th.
The 100-year floodplain is where lenders often require mortgage-holders to carry flood insurance. It’s a measure of probability, meaning each year there is at least a 1-in-100 chance of such an event happening. Over the course of a 30-year mortgage, that amounts to a roughly 1-in-4 chance of at least one flood.
Flaws in FEMA’s program are well-documented. In 2017 the Department of Homeland Security’s inspector general criticized insufficient oversight and slow updates for maps. In many counties, critics say, the models are more than five years old, covering past risks that fail to match updated science and conditions. The agency does not consider future sea-level rise in its maps.
The inspector general warned that “without accurate floodplain identification and mapping processes, management, and oversight, FEMA cannot provide members of the public with a reliable rendering of their true flood vulnerability.”
A FEMA spokesperson said the agency has not evaluated First Street’s tool but added it could give homeowners another source to consult when deciding whether to buy insurance.
“FEMA is constantly working to improve the production of the Flood Insurance Rate Maps within the context of changing conditions,” David Maurstad, deputy associate administrator for insurance and mitigation, said in a statement. A reworking of the risk rating system was set to be unveiled this year but has been delayed until October 2021.