Long-Term Economic Consequences of Coastal Protection Strategies on City Scale Level – When Cost-Benefit Analyses are Insufficient to Identify Feasible Strategies

Abstract

Coastal flood risk accelerates rapidly due to rising sea levels and urban expansion in low-lying areas. Many strategies based on widespread application of hard protection have been developed, but implementation of such measures has raised concerns due to their environmental impact, high costs, and potential increase in vulnerability.This paper focuses on the economic implications of coastal flood protection at the local level, examining impacts on small to medium-sized cities, which reflects many coastal communities around the world. We introduce a framework for assessing the economic burden or benefit of flood protection strategies on local communities and municipalities. We derive standardized values for protection costs, flood risk, and socioeconomic development for typical coastal topologies, i.e., the data usually used for cost-benefit analyses of coastal protection. However, we argue that it is more relevant to consider the feasibility of the strategy by considering costs and benefits for citizens as well as the local community.Protection may be a robust strategy in some landscapes and can generate additional value by enabling gentrification via efficient land reclamation. Other scenarios indicate that a socioeconomic downward spiral in a city may be triggered even though there is a positive business case for coastal protection.

Keywords: coastal adaptation, Protection, Cost analysis, Local scale, Urban development