Prince Hendrik Sand Dike, Netherlands
Nature and protection go hand in hand
Most of the Dutch Wadden Sea island of Texel is below sea level. It is therefore important that the dykes around the island meet the strictest standards, such as withstanding superstorms that occur once every 4,000 years. Because the dike was no longer adequate, Hoogheemraadschap Noorderkwartier, the administrator of this dike, asked us for help.
We provided a solution that incorporated both nature and tourism: a new dune landscape against the old dike and a salt marsh landscape on the sea side. This makes the transition between water and land natural again and protects the island for decades to come. Texel's 14,000 residents and more than a million annual visitors will not have to worry about wet feet. An additional element is the registration of the dyke in Natura2000, the European network of protected natural areas.
Prince Hendrik Sand Dike in numbers
Did you know?
- We built a viewpoint with a fantastic panorama of the whole area. This is accessible to all thanks to an accessible cycle and footpath and a favourite of bird watchers.
- We had discussions with residents and stakeholders about the works and the outcome. This allowed us to respond to their concerns and minimise disruption.
Prince Hendrik Sand Dike in detail
We deployed our trailing suction hopper dredger Bartolomeu Dias to extract sand and bring it ashore via a floating pipeline. In total, it pumped more than 5.5 million cubic metres of sand ashore. With this, we constructed a beach and a sandbank connected to the coast.
We constantly monitored the quality of the sand to achieve the best result. That way, we could be sure that transplanting a salt marsh area would go well.
To keep the sand in place, we applied several sustainable methods. A first is the spraying of paper pulp, which prevents the sand from moving up in the short term. Furthermore, we planted screens of willow twigs and marram grass as more permanent solutions against sand displacement.
With the construction of the new sand dike, the pumping station also had to be adapted. This keeps the polder landscape behind it extra protected.
