Is adaptation planning effective and for whom? The case of Louisiana's 2017 Comprehensive Master Plan for a Sustainable Coast

Flooding in the United States impacts over 40 million people, disproportionately affecting low-income and non-white communities, while costing at least $8 billion annually. Large scale response-based plans have become popular adaptation tools; however, there are limited analyses of their effectiveness and equity. The State of Louisiana's 2017 Comprehensive Master Plan for a Sustainable Coast outlines billions of dollars worth of investments into coastal restoration and adaptation projects with the aim to protect the unique communities and cultures of coastal Louisiana. We reviewed the Plan's storm surge flood-depth modeling to determine the expected beneficiaries of implemented projects and the degree to which the Plan achieves its goals of protecting unique communities and cultures. We constructed two descriptive statistical tests of Master Plan data. We find the Plan is effective at reducing flooding across the region, relative to a future without it. However, racialized populations within areas with high levels of social vulnerability are disproportionately negatively affected or not affected at all. We conclude that the Master Plan is unevenly effective and equitable for the diverse communities of coastal Louisiana.Key planning implicationsLouisiana's 2017 coastal Master Plan fails to fully address existing flood hazards.Where the Master Plan does address flood hazards, it does so unevenly, across existing lines of vulnerability and race. The Master Plan reduces risk for some people but not all, creating winners and losers from adaptation projects.Our findings highlight a persistent issue where the lack of analyses pre- and post-implementation of adaptation plans reproduces maladaptive patterns.