Hydraulic dunes are sedimentary structures formed by the combined action of marine currents and waves. They are relatively frequent in the areas where future offshore farms are planned in the North Sea and the Channel. As part of the electrical connection of these farms, the laying of cables on the seabed will involve cutting and dredging the dunes present.

The assessment of the impact of this type of work requires a better knowledge of the natural evolution of these ecosystems whose sedimentary and biological dynamics are still poorly understood. In addition, due to their extreme morphological variability and potentially high travel speed, hydraulic dunes can have an impact on offshore renewable energy systems and require increased monitoring operations.