First Street notes that most of the homes damaged by Debby are outside the flood zone and are not insured

More than three-quarters of the properties flooded by Hurricane Debby were outside designated flood hazard areas and likely did not have insurance for the water damage. Many of these properties were in locations seemingly far from where the storm made landfall, including Sarasota, Florida; Savannah, Georgia; and Charleston, South Carolina.

This is the conclusion of a report by the First Street Foundation, a nonprofit organization that uses computer models and loss data to assess the risks posed by climate change and storm events.

“Damage from Hurricane Debby was disproportionately concentrated in the state of Florida,” the Aug. 12 report said. “First Street flood model simulation results indicated damages of $2.6 billion to $4.5 billion, of which $1.9 billion to $3.3 billion (~70%) is likely uninsured,” and the event occurred outside FEMA’s special flood hazard area.

Overall, the storm, which made landfall in the Big Bend section of Florida as a Category 1 hurricane, caused up to $12 billion in damage, including about $9.7 billion outside of FEMA-designated flood plains, the report said. About 385,000 properties experienced some level of water reaching the base of buildings, and about 160,000 of those were likely damaged, First Street reported.

“These findings underscore the need to reassess flood risk assessments and preparedness strategies in at-risk areas,” the report says.

Other reports indicate relatively few properties in the area were insured by private or National Flood Insurance Program policies. For example, NFIP data shows that flood insurance rates in South Carolina fell 1.4% last year, The Charleston Post and Courier reported.

“As Debby moved inland, the storm’s slow speed allowed it to dump significant amounts of rain across the southeastern United States,” First Street said. “This caused catastrophic flooding, particularly in parts of Georgia and South Carolina, where several rivers burst their banks.”

One area unexpectedly badly affected by the flooding was Bradenton, Florida, south of Tampa. When water rose to 48 feet behind the Manatee River Dam, local authorities decided to release pressure to prevent a disaster. But the release caused significant flooding downstream and led to more than 200 rescues, the report found.

You can access the full report here.

Top photo: Ann Farkas surveys her flood-damaged home in Canisteo, New York, after remnants of Tropical Storm Debby swept through the area, causing flash flooding. (AP Photo/Craig Ruttle)

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