Studies of eastern flooding guide work in western NC

As director of research at UNC-Chapel Hill’s Institute for Risk Management and Insurance Innovation, H.B. Zeff is part of a hub that brings together investigators and industry professionals to manage financial risks of all kinds of threats, from extreme weather to cybersecurity.

Zeff has done a fair amount of research on the economic impacts of flooding in hurricane-prone eastern North Carolina. But after Hurricane Helene took an unexpected turn toward Asheville and the surrounding region in September 2024, he turned his attention west. His main concern is the “recovery gap,” damages from flooding not covered by insurance.

“The recovery gap is really, really important in understanding how a place is going to recover from a major natural disaster — not just the residential areas but also the commercial spaces, businesses and industries in the communities,” he said.

He’s finding that the “scale of the recovery gap is much greater” in western North Carolina. “Far fewer people there have flood insurance coverage, which creates two challenges. There’s less insurance money to help people rebuild, and we have less information about the scope of the damages.”

The institute is looking at data from several different sources, he said, including home repair payments, local business rebuilding costs and availability of access to utilities, water, power and health care. “Eventually, we’ll put all of those little pieces of information together to paint a better picture of what the scope of the damages were after Hurricane Helene, what the current level of recovery is in that area, and what the future recovery needs might likely be.”

Then the institute will be able to make informed recommendations on next steps for the region. “We’re looking at things like buyouts, development restrictions and ways to get people to purchase more flood insurance,” Zeff said.

Collecting data

Being able to collect information, both financial and visual, is critical for this work. To monitor the flood-damaged areas, the institute’s researchers worked with state agencies to get access to mapping done with lidar (light detection and ranging) technology and digital orthophotography taken from airplanes.

Another Carolina researcher, Antonia Sebastian, is also deeply involved studying flood damage and recovery. An assistant professor in the College of Arts and Science’s Earth, marine and environmental sciences department, Sebastian maps where floods have occurred historically and where they could occur to understand how flood risks have changed over time and could change into the future.

“This is all in the service of trying to say, ‘How can we do better?’” she said. “Our goal is to try to reduce the impacts of flooding over time.”

One process her lab is working to improve is the collection of information about damages and recovery following a flood. In the past, this was a painstaking procedure of going door to door, asking questions. In the aftermath of Hurricane Helene, with funding from the North Carolina Collaboratory, Sebastian’s lab began collecting information more like Google Earth cars do.

“We’re developing a recovery monitoring tool,” Sebastian said. “We have outfitted a car with a GoPro and are conducting drive-by surveys to collect imagery of the damage.”

Operating primarily around Swannanoa, North Carolina, Sebastian’s lab has been collecting these images every quarter, using artificial intelligence to detect change over time. “The idea is that we can monitor how quickly things are recovering and understand those differential recovery rates.”

The tool is still in the piloting phase, but Sebastian has high hopes for its use in the future. “It’s powerful because, if it works, cities and agencies could deploy tools like this after every event, to understand how quickly people are getting back in their houses.”