Kruibeke Bazel Rupelmonde (Belgium): a controlled flood area for flood safety and nature protection

The Belgian Sigma Plan was designed after the 1976 storm-surge disaster, when a dike breach at Ruisbroek flooded the town and required the evacuation of more than 2,000 people; storm-surge floods measured in Antwerp have increased significantly since the 1950s and are expected to occur more often with climate change and sea-level rise.

Reduce flood risk along the Scheldt estuary (aiming for a 1-in-1,000-year protection level accounting for 25cm of sea-level rise by 2050) and provide nature compensation for Antwerp port expansion (150 hectares of bird meadow, 300 hectares of tidal marshland).

Former flood-protection dikes along the Scheldt were lowered and new dikes built further inland, opening the contiguous Kruibeke, Bazel and Rupelmonde polders (600 hectares total) to controlled tidal action via engineered weirs (high weirs let water in at high tide, low weirs let it out at low tide). Through the LIFE-funded SCALLUVIA project (2013-2018), about 90 hectares of alluvial forest and creeks were restored alongside recreational infrastructure (paths, signposts, observation points, fishing).

The area came into operation in 2015 and was tested for the first time during the January 2018 strong tide event, providing a buffer area that helped prevent dangerous flooding. The site created 300 hectares of tidal marsh, 150 hectares of meadow-bird habitat and 91.9 hectares of forest, and is now the most-visited site in the Sigma Plan.

Success factors included creating an integrated, multi-functional space (flood safety, nature, recreation), sustained stakeholder communication, and linking the project to Antwerp port nature-compensation requirements. Nearly 40 years elapsed between the initial proposal and completion, reflecting lengthy political and legal processes, including a dispute over industrial pipeline relocation that delayed completion of the inner dike.