Dredging the sand commons: the economic and geophysical drivers of beach nourishment

Beaches are natural capital stocks that provide value through localized storm protection, recreational amenities, and ecosystem services at regional and global scales. In response to increased storm risks and sea-level rise, coastal communities invest in shoreline stabilization by rebuilding eroding sections of the coast through periodic re-nourishment. While conceptual models of the coastal-economic system provide a capital-theoretic framework to study beach management, empirical analysis of the drivers of beach nourishment policy is limited. Using data from 21 coastal towns in North Carolina, we examine the geophysical and economic factors that reflect coastal vulnerability and influence the frequency of beach nourishment investments. We find that beach towns with access to periodically replenishable sand deposits from inlets and river channels nourish more frequently. Beaches that rely on offshore sand reserves are nourished less frequently. Our results provide new insights into the heterogeneous risks that local communities face with higher costs, limited sand reserves and the growing nourishment demand driven by climate change and increased vulnerability.