The Sand Motor on the Delfland Coast in the Netherlands was created in 2011 as a peninsula covering 128 hectares. It is an innovative pilot project for coastline management intended to contribute to coastal protection in the long term. The intention was also to create an additional appealing area for nature and leisure activities on the Delfland coast and to boost current knowledge about coastline management. A monitoring programme has been conducted for the purposes of knowledge development and in order to evaluate whether the objectives have been met.

In the first year after construction, the Sand Motor changed shape faster than expected but in line with the expected pattern based on model calculations in the design phase. Changes after that were slower than expected. The sand body extends about 260 meters less into the sea than when it was created in 2011. At the same time, the area where the coast has been extended seawards became 2.2 kilometres longer. After four years, 95% of the sand used for the Sand Motor is still in the monitoring area and 80% of that sand is still within the contours of the sand body created in 2011. On this basis, it is legitimate to conclude that the lifetime of the Sand Motor will exceed twenty years.

The Sand Motor is a unique feature on the coast of Holland between the cities Hook of Holland and Den Helder. There is more fine and nutrient-rich sediment in these locations, making richer benthic life possible. And that has a positive impact on other species such as birds and fish.

It will become clear during the coming monitoring period whether or not species that live longer will be able to develop in areas where small layers of sand are deposited regularly due to natural dynamics but that are not covered by thick layers.

During and immediately after construction, attitudes were slightly critical. An increasingly large group now approves of the Sand Motor and the project enjoys widespread support.
No safety problems for leisure visitors arose that could not be managed.

The programme is generating new knowledge that can be used for coastline management, for example with respect to the impact of a major nourishment operation on morphology, leisure activities and the ecology. Some of the knowledge development is already being actively used, an example being the app developed for bather safety

The monitoring of the Sand Motor will continue through to 2021. Rijkswaterstaat is leading the effort. In 2021, there will be a solid scientific evaluation of the Sand Motor concept because we will then have a firmer understanding of how the Sand Motor works.

For more info: http://www.dezandmotor.nl/en/

(Source: SedNet, http://sednet.org/)