Mini Eastern Scheldt Barrier passes extreme storm tests
The Eastern Scheldt barrier has been protecting a large part of the province Zeeland from high water for over 40 years. As the storm surge barrier is in need of major replacements and renovations after decades of use, Deltares carried out extensive scale model tests in 2024 and 2025 on behalf of Rijkswaterstaat. The results are now available.
The water forces acting on key components of the barrier were carefully determined using the scale model and the tests, and compared with the original design objectives.
Why renovation is necessary
Over the coming decades, an increasing number of components of the Eastern Scheldt Barrier will need to be renewed or replaced. These include:
- 124 actuators, including the cylinders that control the gates
- 124 side stops, the rubber buffers between gates and piers
- 62 gates, which will also need replacing in due course
These interventions require significant investment, but are necessary to ensure the barrier continues to function reliably in the future.
Assessment against modern safety requirements
In preparation for the renovations, we are reassessing whether the original designs meet current flood safety requirements. This assessment also takes into account new knowledge, for example regarding sea-level rise and extreme weather conditions.
To better understand the forces to which the structure is exposed, Deltares designed and carried out tests using a 1:40 scale model. Several high-precision sensors were built into this model without altering the shape of the barrier.
In addition, modern wave machines were used, which generated very precise wave conditions directed towards the barrier. This enabled reliable measurements to be taken. To give an idea of the model’s scale: in reality, a sluice is over 40 m long, whereas in the model it is just over 1 m.
Unlike numerical models, the water in the scale model really does ‘its own thing’. This yields results that you cannot always predict in advance.
Martijn de Jong, expert/advisor at Deltares
In the test basins, under controlled conditions, we investigated how water forces act on the most affected components, such as the sluice gates and cylinder rods. With this new scale model, we built on the methodology and results of the original scale model tests, as carried out for the design of the flood defence.
Jesse Simonse, project leader at Rijkswaterstaat: “The research has not only provided important input for the maintenance programme, but has also made a major contribution to knowledge retention and knowledge development for a new generation of engineers working on the Oosterschelde storm surge barrier.”
Read the full interview with Martijn de Jonge and Jesse Simonse here.
Key findings of the research
The scale model tests provide new insights for current and future maintenance:
More accurate determination of wave forces acting perpendicular to the gates
The forces of waves acting perpendicular to the barrier’s gates have been better characterised. This provides valuable data for the further development of models that calculate these hydraulic forces.
New insights into longitudinal forces
Wave forces acting in the longitudinal direction of the gates prove more difficult to assess than the transverse influence of waves, but the tests suggest that these forces may be lower than previously assumed. If this is confirmed by real-world monitoring, it will lead to improvements in the maintenance of the side stops (buffers at the ends of the gates).
Lower load on cylinder rods
The wave load on the cylinder rods, which move the sluice gates, also appears to be lower than originally assumed. This means that heavier waves can be absorbed within the current design targets. This is important for the renovation and has a beneficial effect on the reliability of the flood defences.
Insight into future extremes
Even under very extreme conditions, such as a significant rise in sea level, the tests reveal which scenarios must be taken into account in the future. This knowledge is used to improve maintenance so that the barrier continues to operate reliably in the long term.
Solid basis for future decisions
The results of the model tests, together with data from field monitoring and the further development of numerical models, form a solid basis for the safe and efficient design of the current renovations and future improvements to the Eastern Scheldt Barrier. This ensures that the barrier will remain ready for its task in the future: protecting Zeeland against high water.
