Study Shows Green Infrastructure Addresses Flooding, Insurance Costs From minor water damage to major property loss, more and more Illinois residents are being impacted by climate change and the increased flooding it causes. That’s why The Nature Conservancy and Munich Re, one of the largest reinsurers in the world, joined forces to study how nature-based solutions to flooding, such as restored wetlands, are a viable, sustainable and cost-saving answer to this challenge. We talked to Viv Bennett, the Illinois chapter’s director of protection and conservation strategies, to learn more about how this research can benefit people and nature. What was unique about this study? The benefits of ecological restoration on insurance costs have been studied in areas that experience coastal flooding or wildfires, but never for inland river flooding. With this study, we wanted to develop strategies for resilience on multiple fronts—upgrading infrastructure to incorporate nature-based solutions that reduce flood risks, as well as introducing a community resilience flood insurance model. What research did you conduct? We set out to quantify how a levee setback project conducted by TNC and partners along the Missouri River—and, by extension, other nature-based solutions at other geographies—would reduce flood risk, and how flood insurance premiums might be lowered as a result. What we learned is that a portion of the costs of a nature-based solution could be
recovered from the reduction in premium provided by a new kind of communitybased insurance solution. How does a community-based insurance solution work? Community flood resilience insurance is an innovative concept that was developed as part of this study. Instead of insuring on a home-by-home basis, an insurance company would sell an insurance product to an entire community or subset of a community, to be managed by a local government entity, commercial interest or homeowners association. Through the study, we found that, in some instances, the annual flood insurance premiums for homes and businesses within the areas benefiting directly from the levee setback could be reduced by up to 55 percent through the levee setback coupled with a community flood insurance product.
left: The study focused on a 2019 flood that caused a levee breach along Missouri River (pictured). © USACE right: The levee has been repaired and a wetland installed to capture and absorb future floodwaters. © USACE
How does this benefit nature? Usually, nature-based solutions create additional space for water to expand, reducing how fast it’s flowing while allowing a place and space for land and water to reconnect. This area of reconnection will become habitat for waterfowl, fish, amphibians and many other critical species. Giving space for water to slow down and spread out will also help remove sediment and nutrients that impact water quality. What are the next steps? We are looking for new project sites that have experienced repeated flooding, and where the communities are open to testing and adding some nature-based solutions. Together, we will co-create ways to design and implement these solutions, using the savings from reduced insurance premiums to cover the cost.
nature.org/Illinois 7
