We’ll take Manhattan: Preserving an urban (Southern California) beach in the 21st century

Abstract

The City of Manhattan Beach is updating its Local Coastal Program-Land Use Plan (LCP-LUP), a planning document that regulates development in the city’s coastal zone and establishes a long-range vision for the community. Before embarking on updating the LCP, the city and the community need to better understand coastal vulnerabilities with sea level rise, to analyze the physical and economic risks, and to implement actions to prepare and adapt to the impacts of sea level rise. The authors conducted a Sea Level Rise Risk, Hazards, and Vulnerability Assessment (ESA 2021b) and Adaptation Plan (ESA 2021a). As part of the Adaptation Plan, we compared a “no action scenario” with a potential adaptation scenario designed to mitigate future coastal hazard risks. The economic and fiscal impacts of the no action scenario were compared to the relative costs and benefits of the adaptation scenario. The analysis indicates that sea level rise and the resulting beach erosion may negatively impact the city of Manhattan Beach’s ability to provide visitors with adequate recreational capacity by mid-century. The analysis also indicates that Manhattan Beach and Los Angeles County will lose significant tax revenues without adaptation, approximately $107 million in transient occupancy taxes (TOTs) and $39 million in county (sales) taxes. Adding to beach capacity through dune restoration and nourishment would preserve $65 million in non-market value through 2100. Given these values, it is likely that nourishment or dune restoration would yield the most net benefits as adaptation strategy in the future.