Sand Motor / Sand Engine Nourishment
Background
The Sand Motor/Sand Engine is a type of beach nourishment where a large volume of sediment is added to a coast. The nourishment concept differs significantly from previous beach nourishment strategies in size and morphological development. Traditionally, shoreface nourishments consist of 1-2 million m3 of sand and these projects usually only last for 3-5 years before they need repeating. For the first sand engine, an order of magnitude more sand was used and it is expected to last many times longer. Moreover it is envisioned to spread along the coast, rather than strengthening the coast at the placement area only. Moreover, the long timespan of decades is postulated to reduce the ecological disturbances to the seabed due to less frequent nourishments works. The peninsula shape also facilitates the development of dunes and recreation activities. TUDelft professor Marcel Stive of TU Delft is considered one of the founders of the sand engine concept.
The Sand Engine was constructed at Ter Heijde Beach, roughly halfway between the ports of Rotterdam and The Hague and costing 70 million euros. A volume of 21.5 million m3 of sand, dredged from 5-10 km offshore, covered an area of 128 ha, spanning 2.4 km along the coastline and extending up to 1 km offshore. Work began in January 2011 and conditions were favourable so the operation was completed in October 2011. Being the first large scale mega nourishment with a feeder function, it was baptized a pilot project with several large research and monitoring programmes connected to it.
The sand was deposited in the form of a hook-shaped peninsula and by now the nourishment has been reworked to a smoothly curved beach extension with an alongshore with of about twice the original size. Originally the project was designed to have a lifespan of up to 20 years, however in 2016 it was concluded that it would last even longer than expected.
Research
The Sand Engine has served as an outdoor laboratory for the coastal community from the construction onwards. Over the last years several tests have been conducted where artificial sand bodies were constructed near the waterline to examine erosion processes in a field environment. As such it bridges the gap between field research on natural beaches and (indoor) laboratory experiments.
Visiting tips
The material used from the shallow continental shelf is full of artifacts. It has enabled beachcombers to find artifacts and remains of the prehistoric inhabitants of now-submerged Doggerland.
If you walk along the lagoon you can notice how the different hydrodynamic conditions have changed the bed composition. Digging a few cm deep can expose the anoxic layer.
Originally the peninsula was not vegetated and the dunerow had a straight rectangular profile with planted marram grass. By now (13 years later) you can see how dunes create variability the landscape.
Sand motor programme
- Approximate arrival Bus Stop: 17.20
- Approximate arrival Beach Club: 17:30
- Start walk: 17:30 – see below
- Welcome drinks 17:30 – 18:30
- Busses back to Delft for people that do not join diner: 18:30
- Prepare for diner: 18:30
- First course: 19:00
0 km walk: stay at Beach Club and enjoy the view and company
1 km walk: walk to the beach shore and back, and take your time
4 km walk: walk around the larger lagune in the sand engine. As the tide will be rising (at MSL around 19.00), the best walk is starting at the sea side (guides available).
Beach club BIRDS
Zuiderstrand 19, Strandslag 2, 2555 ZZ Den Haag
Tide (about) during visit:
Many publications have followed from this project. Some examples given here:
Stive, Marcel JF, et al. "A new alternative to saving our beaches from sea-level rise: The sand engine." Journal of Coastal Research 29.5 (2013): 1001-1008.
Roest, Bart, et al. "Observed changes of a mega feeder nourishment in a coastal cell: Five years of sand engine morphodynamics." Journal of Marine Science and Engineering 9.1 (2021): 37.
Van Bemmelen, C. W. T., et al. "Beach scarp dynamics at nourished beaches." Coastal Engineering 160 (2020): 103725.
Radermacher, Max, et al. "Tidal flow separation at protruding beach nourishments." Journal of Geophysical Research: Oceans 122.1 (2017): 63-79.
van Wiechen, Paul, et al. "Measurements of dune erosion processes during the RealDune/REFLEX experiments." Scientific Data 11.1 (2024): 421.
Hoonhout, Bas, and Sierd de Vries. "Aeolian sediment supply at a mega nourishment." Coastal Engineering 123 (2017): 11-20.
Huisman, B. J. A., M. A. De Schipper, and B. G. Ruessink. "Sediment sorting at the Sand Motor at storm and annual time scales." Marine Geology 381 (2016): 209-226.
Herman, Peter MJ, et al. "A mega-nourishment (sand motor) affects landscape diversity of subtidal benthic fauna." Frontiers in Marine Science 8 (2021): 643674.
Luijendijk, Arjen, and Alexander van Oudenhoven. The Sand Motor: A nature-based response to climate change: findings and reflections of the Interdisciplinary Research Program NatureCoast. Delft University Publishers, 2019.