The intention is to protect the village and the area behind it from the sea. The project is a first for the country and will replace the flood defence that currently runs right across Katwijk aan Zee.
Part of the village lies outside the existing flood defence and is therefore not protected. Moreover, the structure is too low to deal with a severe storm. It could be raised but many buildings would be lost and this would change the character of Katwijk.
For this reason, the decision has been made to construct a new flood defence right on the seashore. The new design takes account that the village is overwhelmed by visitors when the weather is fine. Currently, they are parked along the boulevard, obstructing the sea views. This led to the idea of building a car park inside the new flood defence.
The new sea dike will be built using the existing row of dunes between the boulevard and the beach. The dune area itself will be made larger and the new dunes will be where the beach was; a new beach will be created.
The dunes will absorb the first impact of severe storms or high water so that the dyke does not have to be very high. This allows the dyke to be integrated into the coastal landscape: from the beach, dunes are all that will be seen. From the boulevard, the dunes and the sea will be seen.
The car park will be constructed against the dyke and, like the dyke, it will be under a dune. The cars that are now parked along the boulevard will disappear from sight.
The Katwijk Coastal Structure project is a partnership between the municipality of Katwijk, the Rijnland District Water Board, the province of Zuid-Holland and Rijkswaterstaa, the executive arm of the Ministry of Infrastructure & the Environment. The project is part of a programme in which substandard flood defences are being strengthened in 89 places.
Got a story? Email news@theconstructionindex.co.uk
