In this study, we quantify the effects of wetlands in reducing riverine flood losses across the US using flood insurance claims data and annually observed changes in wetland area between 1985 and 2023
We also calculate the marginal value of wetlands in reducing riverine flood losses for each sub-watershed in the US and find that the marginal benefits of flood mitigation outweigh the costs of land conservation in 16% of sub-watersheds
We estimate that each hectare of upstream wetland loss increases flood insurance claim payment amounts by 0.01–0.03%. In total, wetland loss since 1985 has increased NFIP claims by $10.1 billion