The Value of Coastal Wetlands for Flood Damage Reduction in the Northeastern USA

TLDR

Growing exposure to coastal hazards has spurred interest in nature‑based solutions, and measuring their benefits with risk‑modeling industry is essential for accurate risk assessment and aligning conservation with risk reduction. The study quantifies how coastal wetlands in the northeastern USA reduce flood damages from Hurricane Sandy and annual losses in Barnegat Bay, New Jersey. The authors employed high‑resolution flood and loss models, property exposure databases, and synthetic storm simulations to estimate wetland‑induced damage avoidance. Wetlands avoided $625 million in direct damages from Hurricane Sandy and reduced local annual flood losses by 16 % in Barnegat Bay, demonstrating significant risk‑reduction ecosystem services.

Abstract

As exposure to coastal hazards increases there is growing interest in nature-based solutions for risk reduction. This study uses high-resolution flood and loss models to quantify the impacts of coastal wetlands in the northeastern USA on (i) regional flood damages by Hurricane Sandy and (ii) local annual flood losses in Barnegat Bay in Ocean County, New Jersey. Using an extensive database of property exposure, the regional study shows that wetlands avoided $625 Million in direct flood damages during Hurricane Sandy. The local study combines these models with a database of synthetic storms in Ocean County and estimates a 16% average reduction in annual flood losses by salt marshes with higher reductions at lower elevations. Together, the studies quantify the risk reduction ecosystem services of marsh wetlands. Measuring these benefits in collaboration with the risk modelling industry is crucial for assessing risk accurately and, where appropriate, aligning conservation and risk reduction goals.