Nearly $10B in Hurricane Debby damage occurred in areas without flood insurance requirements

Hurricane Debby left billions of dollars of damage in its wake as it moved across the southeastern U.S. last week — losses made all the more devastating because so many of them may have been uninsured.

More than three-quarters of the houses damaged or destroyed by Hurricane Debby were in regions where flood insurance isn’t required, a new report from nonprofit First Street Foundation has found. 

That’s because nearly $10 billion of the slow-moving storm’s estimated $12.3 billion in damage happened in regions outside the Federal Emergency Management Agency’s (FEMA) designated Flood Zones.

FEMA’s flood maps dictate where homeowners are required by law to purchase flood insurance — a financial protection that is becoming increasingly necessary to shield families from crippling losses as flood risk worsens around the country. 

But as climate change driven by the burning of fossil fuels has expanded the area at risk of catastrophic flooding, FEMA’s maps have been slower to change. 

 More than three-quarters of federal flood maps are more than five years old, and more than 10 percent date back to the 1970s or 1980s.

That is due in large measure to Congress kicking the can down the road for 27 straight years on the National Flood Insurance Program (NFIP), the nation’s flood insurer of last resort.

Since the 1990s, that program has been reauthorized only for short-term, one-year periods — rather than for the five years enshrined in statute, which also requires the maps to be redone every five years.

When the latest short-term reauthorization passed in 2023, Rep. Maxine Waters (D-Calif.), a staunch advocate of the program, decried ”a pattern that has put the NFIP repeatedly at risk of lapse throughout the years.”

Waters successfully moved legislation that would have reauthorized the program for the full five years out of the House Financial Services Committee in 2019 — but the legislation failed to pass either the House or Senate.

The reasons for that failure are complicated. But it largely stems from resistance from real estate developers and floodplain municipalities reluctant to see premiums rise, a review in the Journal of Public and International Affairs found.

That resistance has arisen due to a federally subsidized population boom along the coasts that has “created wealth” but also “placed vastly more people and more property in previously undeveloped floodplains and hurricane zones and into harm’s way,” according to a 2014 Cambridge University survey of the program.

That dynamic has effectively created a morass of competing flood maps: the official but out-of-date ones used by FEMA, and a series of competing attempts by nonprofits and other agencies to map the vast, shadowy and expanding extent of national flood risk.

For example, a 2020 report by First Street found that 6 million Americans were likely to live in the “hundred year flood zone” — an area where residents have a 1 percent chance per year of having a foot or more of water in their houses — without knowing it.

That, in turn, means they were less likely to know that they needed flood insurance — an expensive problem for both those individuals and for society as a whole. A 2023 Congressional Budget Office report found that flood damage to homes with mortgages in some way backstopped by the federal government would exceed $250 billion by midcentury.

In some flood-prone regions, the gap between the official maps and the apparent risk led policymakers to effectively throw the federal flood maps out.

In Houston, for example, where Hurricane Beryl recently brought on destructive, widespread flooding and outages, about half of all claims made to FEMA in the three decades before the catastrophic downpour from 2017’s Hurricane Harvey came from properties outside the agency’s flood maps — a fact that has driven Harris County to recommend that all area homeowners purchase voluntary insurance.