4 minute read
Delfland Sand Motor Pilot
The Hague, the Netherlands
The Delfland Sand Motor experiment was a new coastal maintenance strategy designed to harness the power of winds, waves, and currents. The strategy will help protect part of the Dutch coast, while encouraging the development of new beach and dunes, as well as the valuable flora and fauna associated with them. In contrast to typical sand nourishment projects, this was a single mega-nourishment operation that deposited a large quantity of sand in a single location in 2011. The traditional approach to sand nourishment was to maintain the shoreline and to safeguard the hinterland by making smaller-volume sand deposits more frequently, which repeatedly disturbed the ecosystem. A total of about 12 million cubic meters is nourished every year. It is expected that this volume will increase significantly in the coming decades due to sea level rise. This project was undertaken by Rijkswaterstaat, the Province of South Holland, and the EcoShape consortium consisting of partners Royal Haskoning DHV, Wageningen University & Research, Deltares, Van Oord and Boskalis.
Article cover: The Sand Motor, 2012. (Photo by Rijkswaterstaat Joop van Houdt)
Producing Efficiencies
The project was unique in that a much larger quantity of sand was deposited at one time to accomplish the results of multiple nourishments. This mega-nourishment operation deposited 21.5 million cubic meters of sand in a single location, with the height of the deposit rising to five meters above the mean sea level. The traditional approach to sand nourishment had been to maintain the shoreline using a volume of two to five million cubic meters of sand at a time; as a result, the ecosystem was disturbed more often. Since the Sand Motor was completed in 2011, it has been closely monitored, and an extensive research program has been established that will include detailed studies of the project’s evolution and the driving forces behind it, whether they are physical, ecological, or social. Preliminary results show that it has behaved as predicted thus far and that the expected lifetime of the Sand Motor will be longer than the projected 20 years.
Using Natural Processes
The wind and currents are gradually redistributing the sand along the shoreface, beach, and dunes. By using natural processes to spread the sand, this innovative approach aims to limit the disturbance of local ecosystems, while also providing new areas for nature and more leisure opportunities. The strategy of concentrating nourishment operations is seen as a climate-robust and an environmentally friendly way of countering coastal erosion.
Broadening Benefits
The surplus sand creates new areas for nature and leisure. Nature is disturbed much less frequently than in the standard five-year cycle of smaller nourishments, and there is more time for the development of new ecosystems with more biodiversity. Seals have been visiting the area, and a rare plant species has been found growing on a newly formed juvenile dune. The Sand Motor has become a highly popular location for wind-, wave-, and kite-surfers. The Sand Motor has also become a focal point for coastal research and innovative coastal management solutions.
Promoting Collaboration
The Sand Motor pilot is a collaborative effort involving Rijkswaterstaat, the Province of South Holland and the EcoShape consortium, consisting of partners Royal Haskoning DHV, Wageningen University & Research, Deltares, Van Oord and Boskalis. Beach restaurant owners and stakeholders from the fields of leisure, nature, and swimmer safety are involved in the planning, operation, and maintenance process.
