Abstract
With increasing costs of floods across the globe, interest has grown in using managed retreat strategies, such as home buyouts, for flood mitigation. For years, national-level estimates of the benefits of flood mitigation investments in the United States have been estimated as being on the order of 4:1 (USD) or more recently 6:1 (USD), according to the Federal Emergency management Agency and others. Localized evaluation of the true costs and benefits for communities is limited, however, and primarily centered around avoiding direct structural damages. Home buyouts, where individuals’ properties are purchased and removed from risk while reducing impervious areas, are only one of many mitigation options captured in the national estimates. This paper presents a scenario analysis to estimate a localized return on investment of a home buyout program for Nashville-Davidson County, Tennessee in the United States that justifies investment in such programs. It considers the cost of buyouts across the community over several decades. It also compares those costs to benefits such as changes in stormwater attenuation, damages avoided, and exposed populations for a specific extreme flood event. Overall, at a localized scale, the study demonstrates that the return on investment is comparable to national averages, and that proactive implementation significantly increases the value of benefits relative to costs. The approach has potential applicability to other areas in the United States and beyond. It can be used to make the case for investment in such mitigation programs utilizing similarly available data.
Kate Nelson
Assistant Professor, SCALes PI
My research interests include landscape diversity, agricultural adaptation, strategic retreat, vulnerability assessment, and scaling relationships.