Design vision and nature management plan for Sigma projects in the Demer valley

The Demer Valley is a unique river landscape with valuable natural assets. However, the area struggles with water management challenges, resulting in significant ecological stress. This became especially evident following the extreme rainfall event in 2021. The Agency for Nature and Forests commissioned Antea Group to develop a landscape-ecological design vision and a nature management plan. The goal? A climate-resilient valley where water safety, biodiversity, and cultural heritage come together. On behalf of De Vlaamse Waterweg, Antea Group is also working on the technical development of water management measures.

To make the Demer Valley more resilient, we developed a vision in which nature and water management go hand in hand. Design choices are supported by hybrid modeling. Thanks to this river restoration project, the Demer gains more room through reconnected meanders and strategically placed weirs. This raises the (ground)water level and creates opportunities for wetland habitats. At the same time, levee improvements and other safety measures are integrated into the design. Through an intensive participation process - including interactive workshops and scientific grounding - we developed a broadly supported plan in which nature, agriculture, landscape, and climate resilience come together seamlessly.

This project is a collaboration between the Agency for Nature and Forest, De Vlaamse Waterweg nv, and Antea Group. In addition, a wide range of stakeholders were involved, including local authorities, nature conservation organizations, and agricultural associations.