Thresholds for retreat: how perceptions of flood protection shape preferences for relocation

Among the suite of flood risk reducing strategies used for adaptation, voluntary relocation or managed retreat is one of the most extreme. However, without action, the anticipated impacts of sea level rise and environmental change are expected to displace millions of households over the next several decades. These predictions necessitate exploration into how voluntary household relocation decisions could be leveraged as proactive adaptation before it becomes a last resort. Of particular interest are the “thresholds,” or decision points, in which households recognize natural hazards as an unmanageable risk to their safety or quality of life and thus prefer to relocate in response. This research uses mixed methods to examine original survey and interview data collected in 2022 from residents of the Greater Houston and Greater New Orleans regions to explore the relationship between existing adaptation efforts in place and relocation preferences to better understand potential tipping or decision points for households towards relocation. The central research question asked is: What is the relationship between perceived adaptation in place with future relocation preferences? The findings suggest that existing local adaptation efforts are associated with a greater likelihood of preferring relocation response to increasing flood risk as opposed to modifying their current home or doing nothing. This analysis helps to situate relocation as a question of proactive adaptation, a response to failed adaptation, or perhaps neither, pointing towards more complex processes affecting human migration.