The US’s coral reefs save billions of dollars in flood damage

Coral reefs, dubbed the rainforests of the oceans, are among the most biodiverse marine environments on earth. They also perform vital roles in protecting coastlines from erosion, floods and storms.

In fact, in the United States alone coral reefs provide a natural service of coastal protection that can be estimated with specific numerical values, according to researchers at the University of California, Santa Cruz.

The US currently has some 325 kilometers of high-value reefs, most of them in Florida and Hawaii, that are worth more than $1 million per kilometer annually for flood protection alone, according to the experts. In all, the country’s reefs provide a natural flood-protection service to communities that can be valued at more than $1.8 billion annually.

Losing just 1 meter of these reefs in height, meanwhile, would cause 100-year flooding zones to increase by 23%, which would impact nearly 54,000 more people and result in 90% more damages to property to the tune of a $5.3 billion annual increase, the scientists explain in a study.

The researchers reached these estimates by combining computer models of storms and waves with engineering, ecological, mapping, social, and economic tools. They also analyzed flood risks and assessed reef benefits along reef-lined coasts in Hawaii, Florida, Guam, American Samoa, Puerto Rico, the U.S. Virgin Islands, and the Commonwealth of the Northern Mariana Islands.

“Valuing the flood risk-reduction service of existing ecosystems is one step toward managing them as natural infrastructure,” explains Borja Reguero, an associate researcher at UC Santa Cruz, who was the study’s lead author, adding that the research illuminates “how reefs protect communities at the building-block level.”

Protecting reefs from environmental hazards should be done for its own sake. However, this study provides people with a self-interested reason for doing so as well. Namely, by protecting reefs we can protect coastal communities as well.

“These results identify how, where and when U.S. coral reefs provide the most significant coastal flood reduction benefits, helping state and territorial agencies better direct efforts to safeguard lives, avoid economic losses, and meet the goals of the U.S. Coral Reef Task Force to protect and preserve U.S. coral reefs,” explains Curt Storlazzi, a geologist who was a member of the research team.