Study Reveals North Carolina Faces Significant Repetitive Flooding

A new study from the University of North Carolina at Chapel Hill has uncovered that repetitive flooding in North Carolina is far more prevalent than previously understood. The research reveals that more than 20,000 buildings experienced flooding multiple times between 1996 and 2020. This comprehensive analysis, which mapped 78 flood events across about three-quarters of the state, highlights significant impacts on communities beyond the recognized coastal floodplains.

Previously, detailed flood maps were available for only a limited number of events. The research team generated high-resolution maps for over 70 previously unmapped floods, correlating these incidents with specific building locations. Their findings show that over 90,000 buildings flooded at least once, with approximately 43% of these situated outside of the FEMA designated 100-year floodplains, areas typically recognized as high-risk for flooding.

Lead author Helena Garcia, a Ph.D. candidate in the Environment, Ecology, and Energy Program at UNC-Chapel Hill, stated, “We found that flooding in North Carolina, especially repetitive flooding, is more widespread and frequent than we previously knew, and it is often happening outside of places we currently consider as high-risk.”

Historically, flood research and government data have concentrated on major storms, such as Hurricane Florence, while neglecting smaller yet frequent flooding incidents. The study provides a broader, more nuanced perspective by identifying 20,000 repetitively flooded properties within a specific timeframe, contrasting sharply with FEMA’s count of about 13,000 properties since the 1970s. Many of these buildings lacked flood insurance, meaning they were not accounted for in insurance records.

Co-author Antonia Sebastian, an assistant professor in the same program, emphasized the importance of understanding the full scope of flooding impacts: “With this study, we’re painting a much more complete picture. There are lots of floods that go under the radar and don’t make the headlines, but they are just as damaging and disruptive to the families that are impacted.”

The implications of this research are significant and urgent. By pinpointing areas that have already experienced repetitive flooding, the study offers valuable data that can inform more equitable and effective resilience investments. These investments could involve strengthening infrastructure, updating emergency plans, or enhancing support for affected communities.

According to Miyuki Hino, a co-author and assistant professor in the Department of City and Regional Planning, “These findings can help guide more effective resilience investments by identifying communities that have been hit hard by flooding but may currently be overlooked by government programs and policies.”

The research lays the groundwork for future studies examining the long-term effects of flooding on residents, including financial strain, health outcomes, and migration trends. With North Carolina developing a statewide flood resilience strategy, the researchers hope this comprehensive dataset will direct resources to areas in dire need, particularly those that flood frequently but lack visibility or federal assistance.

This study, published in the journal Earth’s Future, represents a crucial step in understanding and addressing the complex issue of flooding in North Carolina. As the state grapples with its flood resilience strategy, the findings will play a pivotal role in shaping policies and investments aimed at protecting vulnerable communities.

For more information, refer to the study titled “Reconstructing repetitive flood exposure across 78 events from 1996-2020 in North Carolina, USA,” available in Earth’s Future (2025). DOI: 10.1029/2025EF006026.