First weak link in range of Dutch dunes at full strength
An integrated dike into the dunescape
The dikes and dunes on the Dutch North Sea coast are under pressure from the rising sea level. The country’s main line of defence against the rising water – the dunes – has to be reinforced in the very short term. Grontmij’s expertise was called in for one of those projects, Kustversterking Noordwijk (Noordwijk Coastal Reinforcement). The new Noordwijk coastline protection was delivered in April 2008.
The dunes at the popular seaside town of Noordwijk were 1 metre too low over a distance of approximately 100 metres. The work to reinforce the range of dunes was carried out across a distance of about 3 kilometres.
Across a distance of about 1 kilometre along the Wilhelmina Boulevard, a dike construction was hidden in the dunes. This construction results in dunes that are 50 metres wider and 5 metres higher (8.5 metres above the Amsterdam Ordnance Datum). The coast line can now weather even high water levels that on average occur only once every 10,000 years.
Our input
Commissioned by the Rijnland District Water Control Board, Grontmij realised both the project management and the process management, and provided virtually all the necessary disciplines for the project.
We drew up the final design and supported the realisation. Furthermore, our consultancy expertise was called in for the compensation of lost revenue for the owners of beach pavilions.
‘Dike in dune’ construction
The reinforcement is a so-called ‘dike in dune’ construction, supplemented by a widened range of dunes on the side of the sea. This innovative solution avoids damage to the landscape. The dike is integrated into the dunescape. In this way, Noordwijk retains its beauty.
Proud
“As an engineer, I am proud of the fact that we solved this rather complex problem with such a fine, innovative solution for the Rijnland District Water Control Board,” says Jana Steenbergen-Kajabová, Coast & Rivers consultant at Grontmij Nederland. “Everything went according to plan thanks to the excellent cooperation between the parties. Moreover, this assignment was in perfect keeping with our ambition to become one of the leading hydraulic engineering firms in Europe.”
Weak links
Tackling weak links is one of the programmes that the Ministry of Transport, Public Works and Water Management instigated to prevent flooding in the Netherlands. The Noordwijk coast is the first weak link to be reinforced. The dunes and dikes of a total of 10 weak links will be reinforced in the period up to 2015, so that even after 2020 they will continue to meet safety requirements. All weak links are expected to be reinforced by 2015.
Facts
Client: Rijnland District Water Board
Finished April 2008