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A team of collaborators, including USGS, released a new report that outlines how coastal communities can reduce risks from flooding and erosion by restoring coral reefs. 

The report, Coral Reef Restoration for Risk Reduction (CR4): A Guide to Project Design and Proposal Development, was produced by scientists from the University of California Santa Cruz (UCSC), U.S. Geological Survey (USGS), the Federal Emergency Management Agency (FEMA), U.S. Army Corps of Engineers (USACE), and National Oceanic and Atmospheric Administration (NOAA). 

Brochure with text and an aerial view looking down on a coast with columns depicting data values along the coast.
Hurricane Damage to Coral Reefs Increases Future Flood Risk. The blue polygons show the results of NOAA surveys of damages to reefs after Hurricanes Irma and Maria in 2017 around San Juan, Puerto Rico. The white bars indicate expected flood risk in the 100-year floodplain before the hurricanes and the colored bar tops indicate how much risk has increased because of damages to reefs per 50,000 m2 (hexagon max width = 277 m).    Full pamphlet image Read page 2

Coral reefs protect coastlines by reducing flooding and erosion, acting as living breakwaters that dissipate wave energy. Each year, reefs protect hundreds of millions of dollars in coastal infrastructure and economic activity in the United States.

“Our prior research has quantified the social and economic consequences that result from storm damage to reefs, which serve as natural infrastructure,” said Mike Beck, Director of the UCSC Center for Coastal Climate Resilience and a coauthor of the report. “Rigorously valuing reef restoration is a critical component to coastal resilience. By calculating the dollars-and-lives value of reefs, we can, for instance, complete FEMA's benefit-cost analysis and access the billions of dollars in federal funding available for hazard mitigation and disaster recovery projects.” 

Agencies including the Department of Defense, FEMA, and USACE are charged with mitigating risks from natural hazards. All are increasingly looking to the role of natural infrastructure in reducing those risks. Coral reef restoration for risk reduction (CR4) projects are designed to reduce flood or erosion risks by rehabilitating, recovering, and restoring reefs. 

The report provides organizations and agencies clear guidance on how to create, design, and implement a CR4 project. It covers critical elements such as project scoping, identification of the project team, selection of site(s), benefit-cost analysis, identification of regulatory requirements, and potential funding opportunities. 

“One important aspect of this work is that coral reefs provide disproportionate protection to minority, low-income, and other at-risk communities,” said Curt Storlazzi, USGS Research Geologist and a coauthor of the report. “By restoring coral reefs with hazard mitigation in mind, we can increase the protection to these usually disadvantaged populations.” 

Read the related press release from UCSC.

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