Sand Motor policy evaluation

Realized in The Netherlands

Sand Motor policy evaluation

The Sand Motor (Zandmotor) was implemented off the Dutch coast in 2011. This is a pilot project aimed at large-scale sand replenishment along the coast. The method involves depositing a large quantity of sand in one go, after which it disperses naturally along the coastline through wave action, currents and the wind. Ten years after construction of the sand bank, it was time to evaluate the project.

The challenge

The Sand Motor project combines several policy objectives: in addition to maintaining the coastline and securing long-term water safety, it was also about developing knowledge and creating a nature and recreation area. Furthermore, large-scale sand replenishment may be cheaper and less ecologically harmful than repeated regular replenishment. The evaluation had to cover all of these goals.

The Approach

We collaborated with Bureau Waardenburg, an ecological research and consultancy firm, to conduct a multidisciplinary policy evaluation. We started with an extensive literature review, which included results from the long-term monitoring programme. We used this as the basis for preparing a knowledge document with specific points to raise in interviews. We then conducted interviews with public and private stakeholders in the following phase.

The outcome of the evaluation was a retrospective of the first 10 years of Sand Motor, as well as recommendations for the future. For example, we proposed the creation of a vision for the future of the Sand Motor. The concept of the Sand Motor and the way that it is set up mean that it will eventually disappear.

This doesn’t have to be a bad thing in itself, but the natural and recreational value will also disappear with it. And when it comes to coastal protection, a successor to the Sand Motor will be necessary – either in the form of regular replenishment, or a large-scale replenishment once again. The creation of a vision is therefore recommended, so that the future management of the Sand Motor after 2021 can look ahead to what happens after the Sand Motor has reached the end of its ‘planned lifetime’.


Creating an understanding of how large-scale replenishment can be used for coastal protection, enabling a decision to be made on the future application of this method.