Some timely analysis on flood defences from Moody’s;
“Floods becoming more frequent and intense underscores the limitations of relying solely on historical flood levels to assess current and future risk,” said Firas Saleh, Director of North American Flood Models at Moody’s. “Risk mitigation remains our frontline defense to help reduce future devastating impacts on communities and economies.”
Key Points
Historic Record Surpassed: The Texas Flood event shattered the area’s previous, century-old record of 36.60 feet set on July 2, 1932.
Comparable to a Dam Break: The rapid rise in Guadalupe River water levels—by over 30 feet in under two hours—and the explosive increase in river flow from approximately 10 cubic feet per second (cfs) to more than 120,000 cfs produced overwhelming hydraulic forces comparable to those observed in dam break scenarios.
Significant Flood Insurance Gap: With only 467 National Flood Insurance Program (NFIP) policies as of May 2025, Kerr County’s flood insurance take-up rate stands at less than 2%.
Today, over 23 million people in the U.S. live behind levees, relying on these systems for protection against flood risk. These levees safeguard more than $2 trillion in property, including homes, businesses, and critical infrastructure. However, the average levee is over 60 years old, meaning many were built before modern engineering standards and designed for a different era, one with less intense rainfall and fewer people in flood-prone areas.
Property-level Mitigation Measures: Elevating first floors above base flood elevation, using flood-resistant materials, and reinforcing structures to withstand high water velocities, can significantly reduce vulnerability during flood events. These localized strategies are especially critical in high-risk areas where infrastructure systems are often aging – the average levee in the U.S. is over 60 years old – and structural defenses may be overtopped or breached.
Explore Further
Additional Moody’s flood risk analysis includes:
- A new Moody’s blog detailing the impact of the Central Texas floods.
- Moody’s new data viz, which includes exploration of flood risks, entitled, Insuring tomorrow: The 10 emerging risks on our watchlist.
- Moody’s study providing a comprehensive retrospective analysis of the populations at risk of flooding over the past 40 years.
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