The value of US coral reefs for flood risk reduction

Abstract

Habitats, such as coral reefs, can mitigate increasing flood damages through coastal protection services. We provide a fine-scale, national valuation of the flood risk reduction benefits of coral habitats to people, property, economies and infrastructure. Across 3,100\u2009km of US coastline, the top-most 1\u2009m of coral reefs prevents the 100-yr flood from growing by 23% (113\u2009km2), avoiding flooding to 53,800 (62%) people, US$2.7\u2009billion (90%) damage to buildings and US$2.6\u2009billion (49%) in indirect economic effects. We estimate the hazard risk reduction benefits of US coral reefs to exceed US$1.8\u2009billion annually. Many highly developed coastlines in Florida and Hawaii receive annual benefits of over US$10\u2009million\u2009km–1, whereas US reefs critically reduce flooding of vulnerable populations. This quantification of spatial risk reduction can help to prioritize joint actions in flood management and environmental conservation, opening new opportunities to support reef management with hazard mitigation funding. A valuation of the flood risk reduction services of coral habitats to people, property, economies and infrastructure in the United States finds that these benefits exceed US$1.8\u2009billion annually.