The Sigmaplan area De Bunt in Hamme, where the Durme river flows into the Schelde, has been officially opened. With 83 hectares of extra space for river water, it better protects the surroundings from floods and simultaneously fosters rare freshwater tidal nature in the heart of Nationaal Park Scheldevallei. The opening coincides with the start of the storm season, a period with a higher chance of storm surges.
In cases of exceptionally high water levels, De Bunt can absorb excess river water. The area combines water safety, nature development, and soft recreation. Separated paths have been constructed along the ring dike for walkers and cyclists, allowing them to safely enjoy the open river landscape without hindering each other.
The area can buffer over 2.5 million cubic meters of water, helping to lower river water levels and reduce pressure on the dikes. Once the tide recedes, the water is discharged. A pumping station also removes water from the surrounding polders, independent of the area's water level. During storm surges, the overflow dike is preventively closed to visitors.
Filip Boelaert, managing director of De Vlaamse Waterweg nv, emphasizes that De Bunt expands the chain of controlled flood zones, thereby better protecting Hamme and the Scheldevallei. He considers the investment crucial for a safe and climate-resilient environment.
Daily, a limited amount of river water flows in and out of the area through the inlet and outlet sluices, promoting the development of mudflats, salt marshes, and reed beds. This freshwater tidal nature provides habitat for numerous plants, fish, and birds, thus strengthening both water safety and nature restoration.
Hans De Schryver, project leader at the Agentschap Natuur en Bos, adds that the Sigmaplan gives rivers and valleys more space, restores natural processes, and creates new nature reserves. He highlights the benefits of wet nature, such as water buffering, CO₂ storage, and water purification.
Lotte Peeters, mayor of Hamme, calls the opening an important milestone. The area better protects residents and infrastructure against storm surges on the Schelde and Durme, while also providing a new natural area for walking and cycling. She urges respect for the safety signage during storm surges.
The construction of De Bunt, which began in 2015, included building a ring dike, outlet sluices, and designing the water channel. The area can now fulfill its role as a controlled flood zone. The surroundings will also see further improvements, including a renovated shelter and an upgraded parking area and site near the monument honoring Filip De Pillecyn in 2027.
The project received additional European support through LIFE SPARC. De Vlaamse Waterweg nv and the Agentschap voor Natuur en Bos collaborate on water safety, nature, and an attractive Scheldevallei, as part of Nationaal Park Scheldevallei.
The Sigmaplan protects Flanders against floods from the Schelde and its tributaries, while developing river nature. The plan involves raising and reinforcing dikes and creating a chain of controlled flood zones for temporary and safe water storage. This gives rivers more space without flooding residential areas and infrastructure. The tidal influence from the North Sea affects the Schelde and its tributaries, like the Durme, far inland.
