Doing Dunes Right

In recent years, the impacts of El Niño events and winter storms on beaches across the state have amplified concerns about how to manage the impacts of longer-term changes to the coast. Approximately 60% of coastal dunes have been lost due to coastal development and land-use change since the 1800s. An additional 24-75% of California’s beaches could disappear under future sea level rise scenarios. The use of coastal dunes has emerged as a popular Nature-based Solution to improve the protection and resilience of beaches and infrastructure, while also improving ecosystem services. However, science on the design and performance of dune restoration as a Nature-based Solution is limited, and best practices do not exist. A review of coastal adaptation plans in California indicates that many coastal communities want to incorporate dune restoration as an adaptation strategy, but are held back by the lack of information and guidelines for effective design, siting, and implementation.

USC Sea Grant is funding this project to enhance empirical understanding of dune restoration trajectories and responses to disturbance through detailed surveys of pilot sites, and to co-design site suitability and performance assessment frameworks for evaluating dune restoration projects on urban beaches with community partners and end users. This project has direct management and policy applications for urban beaches in California, the Pacific coast, and beyond, developing site-suitability and performance-assessment frameworks for dune restoration projects that can be used by researchers, managers, conservationists, restoration practitioners, state and federal agencies, and coastal communities. Data from pilot site surveys will provide new opportunities to refine and extend coastal vulnerability models (e.g., CoSMoS) and assess the lifespan of existing or restored dunes on urbanized coasts under varying sea level rise scenarios. Notably, the dune restoration site suitability framework and the dune restoration performance assessment framework will be the first of their kind, providing new scientifically-informed tools for practitioners and researchers alike. These products will be workshopped with potential users and made publicly available.