Meanwhile, global water and climate risk intelligence firm Fathom is providing flood risk data to the Virginia Dept. of Conservation and Recreation as part of the state efforts to develop a flood protection master plan, expected to be completed by the end of 2025. Fathom is a unit of Zurich-based reinsurer and insurer Swiss Re, which acquired the UK firm in 2023.

The firms say they are providing information that the Federal Emergency Management Agency has not traditionally offered under the scope of existing statutory frameworks. FEMA does not typically evaluate risks associated with flash flooding, and its mapping associated with fluvial flooding from rivers and inland bodies of water is more limited, particularly in rural areas, according to several sources. 

But FEMA maps go through a rigorous public review process, notes Meg Galloway, senior policy advisor for the Association of State Floodplain Managers. The data provided by different vendors can be useful when used appropriately, but they each have their own strengths, and limitations as well, she says, adding that because agency maps undergo a public process, “they’re legally defensible."

FEMA performs base-level engineering to determine where to concentrate its efforts, and usually it’s in the locations that are at the highest risk, Galloway told ENR.

How to Map a Coastline

Jacob Boyd, salt marsh program director for the N.C. Coastal Federation, notes that North Carolina has never had maps with the type of data Natrx is collecting. The goal, he says, is to “have the insight needed to direct resources where they will have the greatest impact.” 

Natrx Chief Operating Officer Tad Schwendler adds that with finite resources, having accurate data will help decision-makers focus on funding projects most critical to protecting human safety and health. “These kinds of issues are acute, and North Carolina is a good example. But this is happening throughout the country, throughout the world, and we believe that more of this kind of work, this resilience and restoration work, needs to happen,” he told ENR. 

The North Carolina team will use a combination of multispectral and remote-sensing data, which will include Sentinel L2A satellite data, aerial imagery and LiDAR from the National Oceanic and Atmospheric Administratio Digital Coast program. “These sources allow us to quantify erosion, analyze wetlands change and model carbon distribution with a high degree of precision across large scale areas like all of eastern North Carolina,” Schwendler said.

The North Carolina analysis is part of a larger effort funded by the U.S. Environmental Protection Agency and being led by the Atlantic Conservation Coalition, which also includes state governments in Maryland, South Carolina and Virginia, in addition to the Nature Conservancy, Coastal Federation and 18 other organizations.

Planning for the Future

In June, Fathom was awarded a contract to provide current and future pluvial, fluvial and coastal flooding data statewide to the Virginia Dept. of Conservation and Recreation to inform a flood protection master plan in collaboration with Arcadis. According to Virginia’s latest hazard mitigation plan, it anticipates about $13 million in damage per year in flood-related events. 

John Millspaugh, Arcadis project manager, said in a statement: “Consistent data across localities is essential for developing a meaningful statewide plan that addresses data gaps and enables comparison across regions.” 

Gavin Lewis, Fathom head of engineering, said in an interview with ENR that the firm—which boasts that it has already mapped much of the country's watersheds and coastlines—seeks to complement what FEMA is already doing. “There’s a lot of good FEMA data out there, but there's a significant proportion that is …15 to 20 years old,” Lewis said. “We’re able to provide that contemporary view of flood risk for people to analyze and get a much clearer understanding at a scale they need for the impact of flooding” whether or communities or assets.