Published on 31 December 2018
Wadis for better water drainage
In low-lying areas of Gieten, which is in the municipality of Aa en Hunze, there are often problems with flooding in the event of heavy rainfall. This is partly because Gieten is located in a hilly area; the difference between the highest and lowest point of the village is about 12 meters. As a result, rainwater drains towards the lower-lying areas even quicker. Disconnecting the hardened drainage surface will reduce this problem considerably.
In Waardeellaan and De Zaalsteden, the sewage system is in need of replacement. The streets are below an average gradient of 1:100 and are therefore ideal for draining rainwater above ground. For this reason, the decision was made to remove all the gullies and drain the rainwater via gutters in the road profile into three water drainage and infiltration systems, or ‘wadis’. Although the residents were initially not very enthusiastic about the plan, this all changed when they were presented with a draft plan in the form of a presentation drawing, which also included a clear explanation of how the system would work and a detailed development plan for the areas around the wadis. Several residents were also willing to help disconnect their rain gutters and pipes. By involving the residents in the initial phase, it was possible to generate plenty of support for the initiative.
The municipality of Aa en Hunze was pleased with the detailed plans. Following the conclusion of the preliminary phase, the municipality decided to incorporate the plans in a set of specifications and asked Witteveen+Bos to further develop the processes for the sewage system replacement, disconnection and construction of wadis. If successful, there is a good chance that this same approach will be used to disconnect several more streets in Gieten.