Prins Hendrik-Zanddijk

  • 5,5 million m³ of sand
  • 2025000 helmet plants
  • 10000 meter anti-drift screens of willow branches

In Texel, a province of North Holland, Jan De Nul offers a nature-based solutions for reinforcing the Prince Hendrik Sand Dike. The island will become bigger and more beautiful with additional natural habitat, and the residents will keep their feet dry.

The solution is in the ecosystem itself

When faced with extremely high water levels, the Prince Hendrik Sand Dike protecting the Dutch island of Texel was in danger of major failure. To prevent this from happening, the responsible local body, ‘Hoogheemraadschap Hollands Noorderkwartier’, started looking for an innovative concept, aware that this would be one of biggest dike reinforcement operations in the Netherlands ever. Jan De Nul Group found the solution: make use of and enhance the local natural habitat.

Texel, one of the Dutch Wadden Islands, has fertile soil for growing flower bulbs, t. The popular tourist destination welcomes about 1 million visitors every year. It is also a crucial resting place and foraging area for birds on their migration routes between north and south and the surrounding water is the ideal habitat for thousands of seals. One problem though: the dike separating Texel from the Wadden Sea is leaking like a sieve.

We will make Texel bigger and more beautiful with additional natural habitat.

Project Lead Dredging Works Benelux Geert Vanwesenbeeck: “This dike was in a very poor condition, probably the worst of all Wadden Sea dikes. Therefore, Jan De Nul is building a new water barrier in the Wadden Sea off Texel. We will make Texel bigger and more beautiful with additional natural habitate. And the residents will keep their feet dry.” A major focus point for Geert, who is also Jan De Nul’s Community Engagement Manager and as such responsible for establishing and maintaining a close dialogue with the residents: “The farmers in this polder landscape live from growing flower bulbs. For the cultivation of these flower bulbs, they need fresh water. However, the agricultural land behind the dike has a very complex soil hydrology. The groundwater layer is salt but also has a thin freshwater lens on top of it. Preserving the balance between salt and fresh water is a difficult exercise because as we are adding sand to this place, extra salt water will seep into the hinterland. That is why we’ve installed a dewatering system to pump salt water back into the sea."

“To explain what we do and how we do it, we organised information sessions for farmers and other residents, this included excursions, monitoring meetings with neighbours and weekly coffee sessions with farmers. We got very positive reactions to this.” Close to the project office, Jan De Nul built a viewpoint, which is also warmly welcomed by both islanders and tourists. “It is a sea container in which we created a passageway connecting to a footpath and bicycle path. Inside, information panels provide more explanation on the project. From the balcony on top of the container, people have a fantastic view over the whole project area.”

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