Coastal Processes, Hazards, and Society

Case Study 3: The Sand Engine – Netherlands


Case Study 3: The Sand Engine – Netherlands

Similar to dune restoration or creation, beach nourishment is a common soft approach to offset erosion. Sand can be mechanically pumped to replenish a beach following a storm or as part of a beach or barrier island restoration project. Alternatively, the natural process of longshore drift transports sand along the coast, not only eroding beaches but also accreting sand and building beaches. In either the mechanical or natural case, the addition of sand to the nearshore zone or beach increases local sediment supply. Mechanical spreading of pumped sand along the coast is common but can have a large ecological footprint and can be very expensive because the sand must be dredged, then transported, and finally distributed along the shoreline – sometimes over considerable distances. To minimize ecological damage and reduce cost, the Dutch developed an innovative way to let nature distribute the sediment instead, making the processes originally responsible for erosion now work on helping to accrete the beaches, at least locally. The concept is not new, but this was the first time that a natural nourishment project of this magnitude was carried out.

Recommended Reading and Viewing

Top two images (2011) show straight line coast, while bottom two images (2012-13) show a bulge out to sea. See caption for more.
The evolution of the sand engine from its construction and dredged placement (top panels) to its natural reshaping by tidal currents and waves (low panels).
Credit: Google Earth