4 minute read
The Polders of Kruibeke
Kruibeke, Belgium
In 1976, a flood broke through the levees in the municipality of Ruisbroek, Belgium, causing significant damage and forcing more than 2,000 people to be evacuated. In response to this event, the Belgian government developed the Sigma Plan as a means of protecting the Seascheldt Basin from future flooding. As part of the Sigma Plan, 13 flood control areas (FCAs) were designed and constructed. The Polders of Kruibeke is the 13th of these FCAs, having been completed in 2015. This area is by far the largest floodplain in Flanders, spanning over 600 hectares (approximately 1,482 acres) of land in the municipality of Kruibeke. In 2005, the Sigma Plan was updated to incorporate new knowledge about climate adaptation. All new FCAs—including the Polders of Kruibeke—are founded on four pillars: safety, ecology, recreation, and economy. The most important pillar is, of course, safety. The Polders of Kruibeke are designed to store excess water from the Scheldt River during storm tide, thus reducing the risk of flooding in urban areas along the Seascheldt Basin. Along with its safety function, the area has been designed to improve the environment by incorporating meadow bird habitats, mudflats and marshes, wetlands, and alluvial forests.
Producing Efficiencies
An FCA is a relatively simple solution that effectively improves the safety of tidal river areas. The height of the overflow levee is very important to ensure enough water can flow into the FCA and thus reduce as much of the storm tide (the storm surge) as possible. Afterwards, a discharge sluice is used to let the water return to the Scheldt River.
Using Natural Processes
Normally the overflow levee doesn’t flood, and the area can be used as both farm land and nature reserve. By using a controlled reduced tide system (CRT) within an FCA, tidal nature can be developed. To achieve this goal, tidal waters are let into the area through a raised intake sluice. The higher position of this sluice ensures a variation in the water levels necessary for the development of marshes within tidal nature. Marshes are essential for restoring the silicate balance in the Scheldt River, providing essential building stones for diatoms at the bottom of the food web.
Broadening Benefits
The FCA offers a valuable and rich nature reserve, easily accessible from nearby towns. Throughout the area, many footpaths, trails, and roads were built to appeal to both local citizens (for example, local fishermen and equestrians) and tourists. Various local businesses have benefited from the increased public attention, and many more have shown interest in becoming part of this growing tourist attraction. The area also provides numerous educational opportunities for all ages. Since its inauguration in 2015, thousands of people have visited the Polders of Kruibeke to enjoy the beauty of the area and the peace and quiet it offers.
Promoting Collaboration
The Sigma Plan was executed by De Vlaamse Waterweg nv (The Flemish Waterways plc) and the Agentschap voor Natuur en Bos (the Agency for Nature and Forests).
Although there was quite a bit of resistance to the project initially, the attitude of many slowly changed to a more positive one over the course of time, thanks to an effective and well-thought-out communication strategy. This strategy was built upon the extensive mapping of the pros and cons for the different stakeholders. By gathering this information, specific efforts could be made for different stakeholders, which led to a positive change in their perception of the project. Today there are many project ambassadors, including some individuals who were at first very skeptical about the project.
The Polders of Kruibeke were also a pilot area for many European Union funding projects; the effort led to integrated water management knowledge exchange and implementation between member states.
