BATON ROUGE — New findings from The Water Institute found that marshland can measurably reduce flooding for nearby homes and reduce insurance risk. 

The Graveline Bay Insurance Pilot, led by the Community Resilience Center at The Water Institute, found that a restored marsh on Dauphin Island, Alabama, led to reductions of 9% to 18% in projected average annual loss for nearby properties. 

The Water Institute is based in Baton Rouge and was founded in 2011 following hurricanes and oil spills. The Institute draws on its roots in the Mississippi River Delta and the Gulf Coast. 

Coastal communities are facing changes in both flood risk and flood insurance costs, according to The Water Institute. 

The Graveline Bay marsh restoration project, funded by the National Fish and Wildlife Foundation Gulf Environmental Benefit Fund and completed in 2023 on the north side of Dauphin Island, restored approximately 60 acres of marsh habitat. The project was originally set up to restore marsh habitat, but the Community Resilience Center saw an opportunity to look at how the reduced flooding would be recognized by the insurance system. 

An analysis done found that the marsh reduced wave heights and water levels across a range of storms. 

“The most important thing we learned is that the marsh is working,” Director of the Community Resilience Center at The Water Institute, Renee Collini, said. “It reduced wave heights and water levels, and the analysis shows that nearby properties are measurably less risky to insure." 

A reduction in estimated average annual loss does not guarantee an equivalent decrease in flood insurance premiums; however, the findings demonstrate that the restoration produced a quantifiable reduction in risk.