Water control is back on track

The Heel and Beesel dike reinforcement project was part of the flood protection program aimed at protecting local villages against flooding from the Meuse river (or Maas in Dutch). Over a stretch of five kilometers (in total) the dikes no longer met modern safety requirements. And so in Beesel we raised the dike and constructed a number of new barriers at locations where these were not yet in place, while in Heel, where the dike was already sufficiently high, we reinforced it so that it would meet the legal standard. This project was a perfect fit for Mourik, who carried it out together with FL in the Dijkversterking Heel & Beesel consortium. The local water board also had desires regarding several specific aspects, i.e. innovation, sustainability and collaboration.

Innovations and solutions for water control

We already had experience with laying bentonite mats (also known as geosynthetic clay liners, or GCL) on a number of projects. Where in Germany this form of dike reinforcement was already a proven solution, the use of these ‘clay blankets’ was a first for the Netherlands. These waterproof mats, together with a layer of local soil, replace the original clay layer on the dike embankment. To stabilize the soil and prevent erosion we used an additive comprising a mixture of minerals: GeoCreteR/GeoStab. To reinforce the dike and prevent backward erosion piping (generally just called ‘piping’), the design also included steel sheet pile walls. The plan was that the steel would be sourced from Belarus, but the war in Ukraine threw a wrench into the works. However, we quickly came up with an alternative solution in the form of plastic. The sheet pile wall now comprises a mix of materials: plastic where only piping was the issue, and steel in places where the dike needed extra stabilization (over some two kilometers).

Sustainable dike reinforcement

Aside from our clients’ wishes, we always look for ways to work smarter, better and more sustainably, for example by using electric (zero-emission) equipment. However, in this dike reinforcement project we took sustainability even further, by using equally strong, but much lighter sheet piling than prescribed, resulting in a reduction in materials, transport and emissions, for example. The smart reuse of clay and soil excavated in Heel in the dike in Beesel is also a good example, with additional soil sourced from the Natuurimpuls Beesels Broek project. Furthermore, we transported the soil and clay to the site by water instead of by road, this way cutting emissions and causing less nuisance and disruption for the local communities. On land that had now become available in Heel we also laid walking paths and stimulated nature development along the banks of the Meuse. Where possible, we engaged local contractors for the planting and paving, among other things. One of the key factors in this project was the tight control of the design, implementation, schedule and budget. As part of this project control, the outcome had to demonstrably meet the requirements, including regarding the design; to ensure and demonstrate this we used the KE-chain digital platform.

Collaboration with the client, as well as with municipal authorities and local residents and businesses, was one of the key MEAT criteria. We went out of our way to invest in this collaboration aspect, for example with team building activities and sessions to get to know and understand each other, supervised by an external agency. We paid a lot of attention to communication with local residents and taking their interests into consideration. Everyone could follow the progress of the project via the BouwApp information app on roadworks and construction and infrastructure projects. To ease concerns about vibration nuisance in advance, we installed meters to record vibrations at all buildings in the immediate vicinity (and checked these afterwards). We also did everything we could to engage locals in the project, for example, by inviting them to the tests with the sheet piling, and by organizing fun activities in the vicinity. All this attention certainly contributed to the end result: despite Covid-19 and the war in Ukraine and the complications these events presented, we delivered the project six months ahead of schedule, without a single safety issue.