Hondsbossche and Pettemer Sea defence
The Hondsbossche and Pettemer sea dyke in the Netherlands was reinforced in 2015, to strengthen the final 'weak link' along the North Sea coast. The innovative project design not only protects the coast but also created space for nature conservation and leisure activities. The resulting area has been renamed Hondsbossche Dunes. The project also presented a unique opportunity for studying the development of dunes and nature following large-scale sand replenishment using the Building with nature principles.
Primary flood defence
The design consists of a soft shallow foreshore, a beach and a varied artificial dune landscape that has the potential to develop into valuable 'Nature 2000 habitats'. Together, these connected systems make up the primary flood defences and provide the desired spatial quality. Since completing the project, the Van Oord-Boskalis joint venture is responsible for maintaining the coastline for another 20 years.
The concerns and preferences of local residents were surveyed, by means of official letters, to determine their reactions to the plan. It turned out that their main concern was that the new dune area would lead to sand being transported into the hinterland of the dyke and into their backyard. In response to residents’ concerns, the design was adapted to minimise sand transport behind the dyke. This was done by creating a buffer area between the dunes and the dyke and by installing willow screens and placing hay bales in this area to capture the sand. Marram grass and the dune lake will also trap most of the sand within the dune area.
Building with Nature
The project uses the Building with Nature principles, with a pro-active approach to creating the dune system, since the dunes are considered an important value. Not only as regards to safety, but also because of their landscape value. Constructing artificial dunes and planting with marram grass creates open areas that not only improve sand catchment but also promote more natural development of the dunes.
Related U.N. Sustainable Development Goals
- industry innovation infrastructure
- sustainable cities communities
- climate action
- life on land
- partnership goals