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. 

We started by determining what it would take to design the dike so that it would be adequate again. We call this the reinforcement task. Since this is a primary dike (the dike protects the inhabitants from 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 a water board are involved in from a water safety perspective.

Port dike along The New Diep

The 2.6 km long dike along the Nieuwe Diep in Den Helder (a primary barrier) protects 1.2 million North Hollanders from high water from the Wadden Sea. The last round of tests showed that part of the dike (959 m) does not meet the latest requirements for water safety. The problem is spread across the harbor dike between Paleiskade and Het Nieuwe Werk.

The illustration below shows the locations of the dike reinforcement where there is a task. No rights can be derived from this drawing, as the safety task is still under investigation.

What's going on?

The dike no longer meets the standard because of multiple technical defects, also known as "failure mechanisms. These mainly involve inward and outward stability.

A dike is not watertight. If the inside of the dike becomes saturated with water, the dike body can become unstable and shear. Piping also plays a role. Piping occurs when groundwater flowing under the dike carries sand particles with it. The resulting 'small channel' weakens the dike. This may occur on the other side of the dike along the Koopvaarders Binnenhaven near the water sports clubs. Finally, in a few places along the dike the revetment is no longer adequate. The (street) stones can become loose or 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 project is currently in the exploration phase (start-up phase). In this phase, additional research is conducted on the dike to assess how safe the dike is, also in view of climate change. We look at possible solution directions and these are worked out in more detail into promising alternatives. From a number of promising alternatives, one best-fit solution, or preferred alternative (VKA), follows. This VKA is chosen on the basis of various criteria, such as cost, sustainability and support.

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

Planning

We are now in the exploration phase. We will complete the exploration phase in early 2025 with an established VKA. This will be followed by the plan execution phase, in which the VKA will be worked out in detail and where the associated permits will be applied for (including an inspection period). This is followed by the realization phase, which is expected to start in 2026/2027.

On October 23, 2024, high water board Arnold Langeveld (Hoogheemraadschap Hollands Noorderkwartier), 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 high water board, the dike will meet the set standard for water safety. In addition, the high water board also wants to cooperate in the future development of the port of Den Helder. This will be 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. 

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

Walk-in meeting April 24

On April 24, a walk-in meeting will be held at the Havenwinkel in Den Helder from 16:00-18:00. During this walk-in meeting there will be the opportunity for the surrounding area to drop by and receive information and ask questions about the preliminary design for strengthening the Harbour Dike.

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 Romee Huisman.

Want to stay informed? Then sign up for the digital newsletter. We will keep you informed of developments several times a year. You can sign up by sending an e-mail to: havendijk@hhnk.nl stating 'newsletter'.