On July 26, 2024, the National Oceanographic and Atmospheric Administration (NOAA) noted a tropical wave developing in the Southern Atlantic Ocean. By August 3, the wave had developed into a tropical storm and was designated Debby. By August 5, the storm intensified into a Category 1 hurricane, making landfall in central Florida. Despite being a relatively weak Category 1 storm, with winds reaching only 80 miles per hour, Debby’s slow movement caused heavy rainfall along its path, with some areas receiving up to 20 inches of rain. The storm moved north, making a second landfall on August 8 in South Carolina, causing flooding and heavy rain along its path before dissipating in the North Atlantic Ocean on August 10.

President Biden approved emergency declarations for Florida, Georgia, and South Carolina, and the Department of Health and Human Services declared a public health emergency. The National Weather Service issued dozens of watches and warnings along the Eastern Seaboard, including for flash flooding and tornadoes. In the wake of the storm, President Biden declared a major disaster in Florida, allowing residents of several counties to apply for aid.

Debby and its aftermath have necessitated a federal response and raised further questions about flood preparation beyond areas deemed high flood risk. The Federal Emergency Management Agency (FEMA) maps the nation’s highest flood risk areas (those with a 1 percent chance of flooding in any given year – the so-called 100-year floodplain) to help citizens make informed decisions based on their risk of experiencing a flood in any given year. For those at the highest risk, federal law requires flood insurance. However, this requirement often leads to a misconception that areas not mandated to have insurance are free from flood risk.

Climate change complicates the development of flood maps. FEMA data shows that 99 percent of U.S. counties have experienced flooding in the last 20 years, and 40 percent of all National Flood Insurance Program (NFIP) claims have been filed outside the high-risk zone. A recent report by the Congressional Budget Office found that only 8 percent of flood-prone properties are covered by the NFIP, with uptake far lower in poorer and minority communities. This poses a predicament for taxpayers, as NFIP is tens of billions of dollars in debt, with premium revenue often insufficient to maintain solvency on an annual basis.

With NFIP not fully renewed since 2012, Congress must reevaluate flood risks. Encouraging greater flood insurance uptake in high-risk and moderate-risk areas is crucial. This could involve offering means-tested assistance programs to help low-income households manage premiums and enforcing mandatory flood insurance in the high-risk zone. Additionally, areas with residual risk, such as those behind levees, should be required to purchase flood insurance, with premiums reflecting both the level of protection and the potential for failure.

Beyond expanding insurance uptake, fostering resilience is key. As climate change expands risk, greater incentives for mitigation efforts are necessary. People often underestimate their risk, making personal mitigation steps seem unnecessary. By incentivizing measures like elevating buildings, vented basements, elevated critical infrastructure, improving drainage systems, and other mitigation efforts, the likelihood of uptake increases, saving money in the long term. Refining systems like FEMA’s Risk Rating 2.0, which ties premiums closely to actual flood risk, can discourage irresponsible development in high-risk areas.

Shortly after Debby moved through the Eastern United States, the First Street Foundation published a preliminary analysis showing that 78 percent of properties damaged by Debby were outside FEMA Special Flood Hazard Areas (SFHA), where flood insurance is mandatory. They estimated $12.3 billion in damage, with $9.7 billion outside designated SFHAs. These estimates highlight the inadequacy of current flood insurance signals and the risk to taxpayers.

The federal response to Debby will likely last for years and incur billions of dollars in damages, with NOAA already listing Debby as a potential billion-dollar disaster. With increasing vulnerability due to climate change, the federal government must ensure that taxpayers are not left on the hook for vulnerabilities stemming from inadequate flood insurance coverage and unaffordable rates for marginalized communities. A significant step would be for Congress to address these critical issues in the reauthorization of NFIP, expiring on September 30, 2024. Once rates are actuarially sound, private flood insurance can step in, which could be vital in increasing uptake and reducing financial pressure on NFIP.