Sand nourishment – Hondsbossche Dunes

Construction

The construction works started with foreshore nourishment using medium size Trailing Suction Hopper Dredgers (TSHD), followed by beach and dune nourishment with jumbo size hoppers. Sand was taken from several offshore borrow areas with varying water depth between 20-28 m and sailing distance between 6 and 11 nautical miles to the project site. By April 2015 all the sand was in place, and the coastal section was officially declared ‘Up to safety standard’ by the Dutch minister of Public Works.

Foreshore nourishment
Beach nourishment (image start of 2015)

The Weak Links project consists of the design, construction and 20 years maintenance of the new coastal protection between Camperduin and Petten. The area has a total coastal length of ~11km. The main objective of the construction was the installation of ~35 million m3 of sand. Most of this volume was needed to create a new dune and beach system that fulfils modern safety standards. Approximately 30% was needed to compensate for settlements,hydraulic and aeolian sand losses and a smooth connection to the adjacent shorelines. Additionally, the dune area was partially planted with marram grass, and amongst others a bicycle path, walking path and other recreational objects were constructed. The nourishment works started on March 3, 2014. 

Foreshore nourishment was placed by means of ‘rainbowing’ by medium TSHD
The sand for beaches and dunes were discharged to site with a sinker-line 

The Hondsbossche Dunes were constructed from Camperduin (south) to Petten (north), following the dominant northern sediment transport direction. The picture below shows the location of the bulldozers and shovels, the hydrodynamic excavator and the dredging ships (hoppers) during the construction works.

Top view and cross section during construction of the Hondsbossche Dunes
Top view and cross section during construction of the Hondsbossche Dunes

In English: foreshore (vooroever), pour front (stortfront), beach and dune (strand en duin), existing HPZ (bestaande HPZ)

bestaande situatie (existing situation), pour set (stortset), hydraulic excavator (hydr. graafmachine), trailing suction hopper dredger (sleephopperzuiger)