Port dyke

Once every 12 years, all dikes in the Netherlands are tested for water safety. The harbor dike adjacent to the Nieuwe Diep in Den Helder was assessed in 2021. The dike is not safe enough in a number of places.  

In 2023, we (as administrator of the dike) started determining what is needed to design the dike so that it once again meets the standard and is safe enough. We call this the reinforcement task. Since this concerns a primary water defense system (the dike protects the inhabitants against the water from the sea) the project was included in the national Flood Protection Program(HWBP). 

So this is not about the developments around the Dijkkwartier, which is another project that we as the Water Board are involved in from a water safety perspective. 

Port dike along The New Diep 

The 2.6 kilometer long harbor dike along the Nieuwe Diep in Den Helder (a primary flood barrier) protects 1.2 million North Hollanders from high water from the Wadden Sea. The last round of tests in 2021 and additional calculations made in 2023 showed that part of the dike (655 m) no longer meets the legal standard set for water safety. This concerns a task that is spread across the Harbour Dike between the Paleiskade and the Koopvaardersschutsluis. 

The illustration below shows the locations of the dike reinforcement where there is a task. No rights can be derived from this drawing. 

What's going on?

The dike no longer meets the standard for water safety in a number of places due to multiple technical defects, also known as 'failure mechanisms'. This applies opposite the former 'pilotage building' (Fish Auction subarea) and at Het Nieuwe Diep and Het Nieuwe Werk.

The dike no longer meets inward and outward stability in a number of places. A dike is not watertight. If the inside of the dike becomes saturated with water, the dike body can become unstable and shift. In addition, in some places along the dike the revetment is no longer adequate. The (street) stones can become loose and be washed away by waves.

What are we going to do?

Dike reinforcement projects are divided into three phases: exploration, plan development and realization. The exploration phase took place in 2023 and 2024. In this phase, several alternatives were conceived and worked out that could make the dike safe again. From these alternatives, the preferred alternative (VKA) was chosen in late 2024. This VKA is the best suited solution to make the dike compliant again. For the Port Dike, a VKA was developed for each subarea. In early 2025, the exploration phase was completed with the adoption of the VKA by the board of HNK.

In front of the Fish Auction, a sealing layer will make the dike more waterproof on the outside.

For Het Nieuwe Diep, outward stability will be improved by replacing the quay structure, combined with a widening of the quay area where the existing clinkers will be replaced with heavier cladding to make it more resistant to waves.

At The New Work, the existing clinkers on the on- and off-ramps will also be replaced with heavier cladding.

The project is currently in the plan execution phase. In this phase, the VKA is being worked out in detail into a technical design. To do this properly, detailed information is needed from and about the area. Therefore, various studies are being carried out. For example, research into protected animals and plants, the presence of archaeology and unexploded ordnance and the composition of the subsoil. The planning phase concludes with the project decision and the most important permits needed to make this project possible. The project decision describes the project and provides insight into measures and facilities in the physical environment to realize the project.

Want to know what else is involved in dike reinforcement? Then browse digitally through the book Dikes for Beginners

Widening quay the New Diep

On October 3, 2024, high water board Arnold Langeveld (HHNK), Alderman Fotigui Camara (Municipality of Den Helder) and director Kees Turnhout (Port of Den Helder) signed the cooperation agreement "Widening Kade Het Nieuwe Diep. With the dike reinforcement of the Water Board, the dike will meet the set standard for water safety. We also want to cooperate in the future development of the port of Den Helder. This is done by taking into account a wider quay, the future deepening of the shipping channel and a good connection to Het Nieuwe Werk in the design of the dike. The execution and cost sharing of this work have been well agreed upon in the cooperation agreement.

Planning

In early 2025, the exploration phase was completed with an established VKA. This is followed by the plan execution phase, in which the VKA is worked out in detail and the corresponding permits are applied for. This is followed by the realization phase, which is expected to start 2026/2027. 

The schedule (draft) is subject to change. No rights can be derived from the schedule.

Who do we work with?

We work together with many different parties. Think of residents and entrepreneurs along and on the dike, Municipality of Den Helder, Department of Public Works, Province of North Holland, Maritime Cluster, Royal Navy, Defense and the Port of Den Helder.

Questions and contact

If you have any questions, please contact us via our contact form or via the general number: 072-582 8282 and ask for the environmental manager Stefan van den Helder.

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