Five years after the Sand Motor emerged from the waves, the results of the first major evaluation have been published. The conclusions are positive. Five years ago the scheme started with three goals: increase coastal safety, create extra space for leisure and nature and contribute to knowledge development about coastal management. Results show that these goals are achieved, sometimes even better than expected.
Before the trial began, the Sand Motor was expected to last for twenty years. It was thought that the sand would be spread along the Delfland coast during that time. That will probably take longer. At present, the Sand Motor is already supplying sand to a five-kilometre stretch of coast. In the first four years, almost a million cubic metres of sand was moved to the south and about 1.5 million cubic metres has been moved to the north. Dunes in the coastal area near the Sand Motor have grown less quickly than expected. However, this has not affected the level of protection afforded by the coast since the coast was already strong enough before the Sand Motor. The main reason the dunes are growing more slowly is that the sand has to cover a relatively large distance before reaching the dunes.
The number of plant species and the number of places where they grow in the Sand Motor are increasing. Most vegetation consists of sand couch and marram. Sea holly, a red-list variety, is growing in some locations. There is also marram around the dune lake. A strip of low vegetation has formed near the waterline. There is an abundance of aquatic flora in the dune lake itself. Fifty varieties of bird were seen around the Sand Motor during the first five years. The black-headed gull was the most abundant species by far, accompanied by common gulls, herring gulls, grebes and cormorants. Several types of wader, such as the oystercatcher, are also visitors to the Sand Motor. There is also a large population of sea bed organisms (benthos) around the Sand Motor.
At the outset, everyone was curious about the impact on leisure. Five years later, a wider range of leisure activities have been seen on the beach between Ter Heijde and Kijkduin. There are fewer bathers: people who come purely for sunbathing and swimming. At the same time, there are more people who come for day trips to the Sand Motor, more visitors with dogs, more kite surfers and more evening visitors.
The Sand Motor is an experiment covering a period of twenty years. Obviously, the area will continue to develop. There will be another evaluation in 2021. At that time, we will probably be able to provide answers to questions that remain unanswered at present because the evaluation period has been too short. For example: is a one-off sand-nourishment operation such as the Sand Motor better for benthos than a standard programme in which sand is deposited in the same place about once every four years to maintain the coast? And an equally interesting question: is the Sand Motor cheaper than the standard approach? We know by now that the Sand Motor is a realistic alternative for coastal management in terms of both costs and effect. It is not yet possible to say for certain whether the Sand Motor is really more economical.
The Sand Motor has become an international icon of innovation. In Jamaica as well as in Norfolk in the United Kingdom, there are plans for a sandy strategy like the Sand Motor.