In order to give the Scheldt more room, a controlled flood area has been created from the Sigma area Wal-Zwijn (170 hectares). This will protect Hamme and the wide surrounding area against flooding.
Herbosch-Kiere constructed a ring dyke 6 m high, 7 m wide and 3 km long to protect the surrounding residential area against flooding. First of all, we took out all the trees in the zone and determined the boundaries of the area for mapping. Before starting the groundworks, we removed any obstacles at the site which mainly included concrete elements, pipes, rocks, etc.
Before we could construct the ring dyke, we had to get rid of the ponds and watercourses in the area. The ring dyke was built using the earth that had been excavated during previous dredging works in the Durme, sand from the depoldering of Groot Schoor and earth removed from the streams and channels in the flood area. This amounted to 400,000 m³ of earth.
At the base of the ring dyke, we used a crane to deposit rubble to strengthen the dyke. This involved a total of 17,200 tons of material. Finally, we built the towpath by covering the dyke with asphalt.