Worst Flood Disasters in U.S. History
Flooding has shaped U.S. history, damaged entire regions, and changed how communities manage risk. While every disaster is different, the events below are widely recognized for their scale, human impact, and long-term consequences.
Important reminder: Your exact flood risk is property-specific. One neighborhood’s experience can be very different from another just a mile away.
Five major floods that changed the U.S.
1) Hurricane Katrina (2005)
A catastrophic hurricane and flood disaster driven by storm surge and major levee failures in the New Orleans area.
Why it stands out
- One of the deadliest and most costly U.S. disasters in modern history.
- Massive displacement, long-term housing impact, and infrastructure failure.
2) Hurricane Harvey (2017)
Harvey stalled near the Texas coast and produced historic rainfall totals, leading to widespread catastrophic flooding.
Why it stands out
- Produced rainfall totals over 60 inches in parts of southeast Texas.
- The National Hurricane Center notes Harvey as the second-most costly U.S. hurricane after inflation, behind Katrina.
3) Great Flood of 1993 (Midwest)
Months of persistent rain caused the Mississippi and Missouri River systems to overflow, flooding large portions of the Midwest.
Why it stands out
- Long-duration flooding across multiple states.
- USGS reports 52 deaths and approximately $15 billion in damages (as reported at the time).
4) Great Mississippi Flood (1927)
A landmark flood on the lower Mississippi River that triggered major changes in U.S. flood control policy.
Why it stands out
- Flooded roughly 27,000 square miles and displaced hundreds of thousands of people.
- Often cited as one of the most consequential U.S. river floods in history.
5) Rapid City Flood (South Dakota, 1972)
A nighttime flash flood in the Black Hills region that overwhelmed communities with little warning.
Why it stands out
- National Weather Service documentation reports 236 fatalities and damages around $100 million (in 1972 dollars).
- Flash floods like this remain some of the most dangerous flood events because they can develop fast and at night.
Quick comparison table
| Event | Type | What made it extreme | Common takeaway |
|---|---|---|---|
| Katrina (2005) | Hurricane + surge + levee failures | Coastal surge and catastrophic urban flooding | Infrastructure failure can turn a storm into a long-term disaster |
| Harvey (2017) | Hurricane + extreme rainfall | Slow movement and record-setting rainfall | “Rainfall floods” can impact huge inland areas |
| Midwest (1993) | River flooding | Long-duration basin-wide flooding | Flood risk is not just coastal or “flash” events |
| Mississippi (1927) | River flooding | Historic river overflow and displacement | Major floods reshape policy, mapping, and building practices |
| Rapid City (1972) | Flash flood | Fast, deadly, nighttime event | Speed matters: flash floods are especially dangerous |
What these floods mean for homeowners and commercial property owners
Flood risk is not just “water near your house.” It’s about rainfall patterns, drainage capacity, local topography, river systems, and storm surge, plus how the built environment handles water.
If you want a practical next step after reading this article:
- Check flood mapping and local flood history for your exact address
- Understand the difference between “mapped risk” and “real-world risk”
- Make sure your insurance strategy matches your building’s replacement cost and exposure
