Dynamic revetments are nature-based solutions designed to mitigate coastal erosion along the high-energy wave environment of the Pacific Northwest coastline. These structures replicate the characteristics of natural composite beaches, which feature a sandy lower beach profile backed by a cobble berm. In a dynamic revetment project, the cobble berm may be positioned to protect a coastal bluff or natural or constructed dunes.

One of the few erosion control methods capable of withstanding the region’s powerful wave forces, dynamic revetments have demonstrated success in several coastal applications. Despite their promise, significant knowledge gaps remain regarding optimal design practices, maintenance frequency, and the mechanisms by which these structures dissipate wave energy, reshape under wave action, or even encourage sand accretion. Further research is needed to establish robust design guidelines and improve our understanding of how dynamic revetments function as an effective “engineering with nature” solution for coastal resilience.

We are exploring key engineering metrics to better define design constraints for dynamic revetments. As part of this effort, we are developing a state-of-the-practice publication that consolidates insights from approximately 70 stakeholders, including engineers, managers, and academics, to address knowledge gaps in dynamic revetment design.

Our field campaigns focus on understanding the dispersion of natural composite beaches and dynamic revetments. This includes analyzing the grain size distribution and its temporal and spatial variability at these sites. Additionally, we are quantifying the amount of sand trapped within the cobble matrix of dynamic revetments, which may influence sand supply to the back dunes.

Beyond structural performance, we aim to assess the ecosystem services provided by dynamic revetments. This includes evaluating their role as habitats for native species compared to traditional grey rock revetments, offering a broader perspective on their ecological value.

On the left is a map of the Southern Washington and Northern Oregon coasts, with colored boxes indicating dynamic revetment projects. Corresponding-colored boxes contain satellite imagery (middle) and a site photo (right). The approximate extent of the dynamic revetment is outlined in red on the satellite photo. Figure Credit: Hailey Bond