Helderse Sea Wall

This project is separate from developments surrounding theDijkkwartier. That is a different project in which we, as a water board, are also involved. 

The Helderse Sea Wall

The Helderse Zeewering is approximately 5 kilometre and protects North Holland residents from high water from the North Sea. In 2023, we (as the dike's administrator) began investigating what is needed to design the dike in such a way that it once again meets safety standards. We refer to this task as the reinforcement task. 

 The image below shows the location of the dike reinforcement where the task applies. Please note that this is a rough visual representation.

What's going on?

At the Helderse Zeewering, the asphalt on the outside of the dike no longer meets safety standards. In the period 2022-2024, we conducted further research into the exact problem and the appropriate solution. An important topic from the research is the groundwater level in the dike during a storm with high water. To this end, we collected measurement data using monitoring wells during two storm seasons.

During a storm with extremely high water levels, the groundwater in the Helderse Zeewering can rise to below the asphalt. Pressure differences and high waves put the asphalt under stress and the waves can break it. See the image below.

What are we going to do?

Currently, the dike surface consists of asphalt, riprap, and a berm. With the chosen solution, part of the asphalt surface will be replaced by riprap. With this modification, we will remain below the bike path on the dike.

The preferred alternative (VKA) has now been further developed into a preliminary design. It has been announced that the asphalt up to the level just below the cycle path will be replaced by setts with a layer of rubble and/or mine stone underneath. The appearance of the dike will be the same everywhere after the reinforcement. However, the design distinguishes between the dike south of Kaap Hoofd and north of Kaap Hoofd. South of Kaap Hoofd, the waves are heavier, so a thicker layer of stone revetment will be applied here than on the side north of Kaap Hoofd. The appearance of the dike will be the same on all sections. 

On October 1 and 2, 2025, two information meetings were organized during which, among other things, the preliminary design was presented. The presentation and frequently asked questions during these meetings can be found at the bottom of this page.

At Cape Hoofd, there is also a maintenance task of approximately 1,200 meters. Here, the asphalt on and above the bike path needs to be replaced. This is not part of the dike reinforcement that we have to do for the water safety task, but we will include it at the same time. On this section, the work will therefore extend above the bike path. 

Current state of affairs

The project is currently in the plan development phase. In this phase, the preliminary design will be further developed into a final design that can be used by the contractor. The planning phase will be concluded with the project decision and the most important permits required to make this project possible. The project decision describes what the project will look like and provides insight into the measures and facilities in the physical living environment that are required to realize the project. 

Would you like to know more about what is involved in reinforcing a dike? Then take a digital look through the bookDikes for Beginners.

Planning

The exploratory phase will be completed by the end of 2024 with a finalized VKA. The plan development phase will then commence. The final design will be completed in early 2026, after which the relevant permits will be applied for. The implementation phase is expected to start in 2027 or 2028.

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

Who do we work with?

We collaborate with various parties, including residents and businesses along and on the dike, the municipality of Den Helder, the province of North Holland, Rijkswaterstaat, as well as research agencies and external dike experts.

Learn more

If you have any questions, please contact us via ourcontact formor call our general number +31 (0)72 582 8282 and ask for the environmental manager, Nienke Schut.