Study Reveals Widespread Flooding in North Carolina Exceeds Expectations

A recent study from the University of North Carolina at Chapel Hill has uncovered that repetitive flooding in North Carolina is far more common than previously recognized. Between 1996 and 2020, over 20,000 buildings experienced multiple flooding events, highlighting significant gaps in understanding the impact of flooding on communities throughout the state.

This research mapped 78 flood events across roughly three-quarters of North Carolina, challenging the notion that severe flooding is confined to coastal areas. Until now, detailed flood maps were limited to a few major incidents, but the study created high-resolution maps for more than 70 previously undocumented floods, pinpointing their locations in relation to buildings.

Over 90,000 buildings flooded at least once during this period, and notably, 43% of these structures lie outside of FEMA’s designated 100-year floodplains—regions officially recognized as high-risk. “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,” said Helena Garcia, the study’s lead author and a Ph.D. candidate in the Environment, Ecology, and Energy Program at UNC-Chapel Hill.

Previous analyses and government data focused primarily on significant storms like Hurricane Florence or insured properties. This new research breaks ground by presenting a more comprehensive view of flooding, capturing events that often go unnoticed. According to FEMA, approximately 13,000 properties have been repetitively flooded in North Carolina since the 1970s. In contrast, the UNC team identified more than 20,000 buildings affected from just 1996 to 2020, many of which were not covered by flood insurance and, therefore, would not have appeared in insurance records.

“We’ve always known flooding is a threat to NC, but the focus has been on only the biggest events,” remarked Antonia Sebastian, lead advisor and assistant professor in UNC-Chapel Hill’s Environment, Ecology, and Energy Program. “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. By identifying areas that have repeatedly experienced flooding, the findings can inform more effective resilience investments. This could involve enhancing infrastructure, revising emergency planning, or providing better support to affected communities. “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,” explained Miyuki Hino, co-author and assistant professor in the Department of City and Regional Planning.

The researchers aim to establish a foundation for further studies that explore the long-term effects of flooding on residents, including economic stress, health outcomes, and migration trends. As North Carolina develops a statewide flood resilience strategy, they hope this comprehensive dataset will direct resources to areas that have historically been overlooked, particularly those that experience repeated flooding without adequate federal support.

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