What happens when water beats over the dyke?
Expert(s) |
Huub De Bruijn
Deltares and the Dutch Water Authority Rivierenland jointly conducted a field experiment in the Dutch town of Ochten this week, to test the strength of a dyke. The aim was to find out what happens when water hits the dyke at high tide.
Wave overtopping
For this purpose, a field experiment was conducted in which overtopping waves were simulated using a tube with holes. Water flowed down a width of 30 metres from the dyke. A pump was used to control the amount of water.
Results of the field experiment
During the test, which is part of the ‘Stability in Wave Overflow’ project, we looked at what happens to the dyke. We examined whether cracks appeared in the dyke revetment or whether it might even shear off. We also looked at how much water infiltrated the slope. The test dyke held up well and was able to handle the large amounts of water.
Preliminary research
Experts from Deltares and Waterschap Rivierenland have been researching the stability of the dyke during wave overtopping for years. This allows us to find out what the risk of flooding is due to wave overtopping. If more water is allowed to wash over the dyke, the dyke does not have to be as high and wide. This means that the dyke takes up less space when a dike is being reinforced.
Cooperation
The ‘Stability in wave overtopping’ project is made possible by the Dutch National Programme 'Hoogwaterbeschermingsprogramma (HWBP)'. In this programme, the water boards and Rijkswaterstaat work together on the largest dyke reinforcement operation since the Delta Works. Over the next 30 years, at least 2,000 kilometres of dykes will be reinforced, including 400 kilometres in the Rivers Region.
