Katwijk is to have a new flood defence: a row of dunes that incorporates a dike as well as a car park. The project is unique in the Netherlands.
A flood defence currently runs right across Katwijk aan Zee. Its intention is to protect the village and the area behind it, right though to Leiden, from floods. Part of the village lies outside the 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: a row of dunes that incorporates a reinforcing dike.
Katwijk also has another problem: when the weather is fine, the coastal village is overwhelmed by visitors to the beach. What can be done about all those cars? 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 project is unique in the Netherlands.
Dikes and dunes
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 therefore moved up a bit. The new dunes will be where the beach was. A new beach will be created through sand suppletion. The dunes will absorb the first impact of severe storms or high water so that the dike does not have to be very high. Thus, the dike is integrated into the coastal landscape: from the beach, all you see are dunes, and from the boulevard you see the dunes and the sea. This means that Katwijk remains safe, liveable and accessible.
The ‘dike-in-dune’ concept is explained to Minister Schultz van Haegen during a working visit on 6 February 2014.
A car park will be built on the Voorstraat. It will be constructed against the dike, and like the dike, it will be under a dune. The cars that are now parked along the boulevard will disappear from sight.
The construction of the Katwijk Coastal Structure is already well underway. Work began on creating the new beach in October 2013. Construction of the dike began last December and this month work on the car park will start. The project should be delivered by the end of the year. The beach will be accessible as usual during the upcoming beach season, from April to October.
The Katwijk Coastal Structure project is a partnership between the municipality of Katwijk, the Rijnland District Water Board, the province of Zuid-Holland and Rijkswaterstaat (the executive arm of the Ministry of Infrastructure and the Environment). The project is part of the second High Water Programme in which substandard flood defences are being strengthened in 89 places.