Published on: March 17, 2026, 10:21 AM
In 2026, the Oosterschelde Barrier has protected a large part of Zeeland against high water for 40 years. Because the storm surge barrier requires major replacements and renovations after decades of use, Deltares conducted extensive scale model tests in 2024 and 2025 commissioned by Rijkswaterstaat.
The results are now available: the water forces on important parts of the barrier have been carefully determined and compared with the original design goals.
Why renovation is necessary
In the coming decades, more and more parts of the Oosterschelde Barrier need to be renewed or replaced. These include:
- 124 moving parts, including the cylinders that operate the gates
- 124 side buffers, the rubber bumpers between gates and pillars
- 62 gates, which will also need replacement in due course
These interventions require significant investments but are necessary to keep the barrier reliable in the future.
Testing against modern safety standards
In preparation for the renovations, we reassess whether the original designs meet current flood safety requirements. New knowledge is also incorporated, for example about sea level rise and extreme weather conditions.
To better understand the forces acting on the structure, Deltares designed and conducted tests with a scale model, at 1 to 40. Several good measuring sensors were installed in the model without changing the shape of the barrier.
Modern wave machines were also used, which precisely generated wave conditions towards the barrier. This allowed reliable measurements. To give an idea of the models size: in reality, a gate is over 40 m long, and in the model it is just over 1 m.
In the test basins, under controlled conditions, the water forces on the most affected parts, such as the gates and cylinder rods, were studied. This new scale model built upon the methods and results of the original scale model tests conducted for the barriers design.
The research has not only provided important input for the maintenance task but also made a significant contribution to knowledge retention and development for a new generation of engineers for the Oosterschelde Barrier.
Main findings of the research
The scale model tests provide new insights for current and future maintenance.
More accurate determination of wave forces perpendicular to the gates
The forces of waves acting perpendicular to the barrier gates have been better mapped. This provides valuable data for further development of models calculating these water forces.
New insights into longitudinal forces
Wave forces along the length of the gates appear to be more difficult to assess than transverse wave effects, but tests indicate these forces may be lower than previously assumed.
If confirmed by real-world monitoring, this will lead to improved maintenance of the side buffers (bumpers at the ends of the gates).
Unlike numerical models, the water in the scale model really 2018does its own thing2019. This results in outcomes that you cannot always predict beforehand.
Lower load on cylinder rods
The wave load on the cylinder rods that move the gates also appears to be lower than originally assumed. This means heavier waves can be absorbed within the current design goals. This is important for renovation and positively affects the barriers reliability.
Insight into future extremes
Even under very extreme conditions, such as high sea level rise, the tests show which scenarios must be considered in the future. This knowledge is used to improve maintenance so the barrier remains reliable in the long term.
Strong basis for future choices
The results of the model tests and analyses provide a solid information base for a safe and efficient design of current renovations and future improvements of the Oosterschelde Barrier. This ensures the barrier remains ready for its task: protecting Zeeland against high water.