The Netherlands’ system of dikes and sea gates has long been the best in the world.
This is the Sand Engine, one of the latest innovations from Dutch masters of flood control technology and designed, as the national water boardRijkswaterstaat says, so that “nature will take the sand to the right place for us.” After having constructed the country’s vaunted system of sea gates and dikes, Dutch planners and engineers are now augmenting it with new technology enlisting nature to keep the water at bay.
The Sand Engine is the signature project of Building with Nature, a consortium of Dutch industries, universities, research institutes, and public water agencies looking to harness natural systems for next-generation hydraulic engineering. Completed in late 2011 at a cost of 50 million euros ($67 million), the Sand Engine’s goal is to provide long-term fortification for eroding beaches as ocean currents gradually redistribute its dredged material. Until now, this coastline needed sand replenishment every five years, requiring expensive dredging that damaged marine ecosystems. The Sand Engine will feed beaches for about 20 years at half the price, said Marcel Stive, chair of coastal engineering at Delft University of Technology (TU Delft) and principal creator of the technology.
“At this moment, this is the safest coast we have,” Stive said. When the sand is fully spread out, it will protect 20 kilometers (12.4 miles) of shoreline from the current rate of sea-level rise, he said. If the amount of water increases, “we’ll just add more.”