Protecting Flanders, today and tomorrow

Because of climate change and rising sea levels, it is crucial to keep investing in the Sigma Plan. The Sigma Plan is about higher and wider levees, a chain of flood areas along tidal rivers (FCA and FCA-CRT) and local depoldering. This is how we protect the entire region of Flanders from flooding from those tidal rivers at storm tides. A storm tide happens when a spring tide in the Sea Scheldt Basin coincides with a (north)westerly storm on the North Sea. We are also restoring the natural bends or meanders of the rivers in certain places. That is because they are natural buffers during periods of high precipitation. In summer, they also stop areas from getting too dry, just like barriers on the riverbed.

Flooding of Polders of Kruibeke during storm Corrie in 2022, ©Vilda

Protection against storm surges

We are raising and strengthening the levees to make sure they can withstand storm surges. We do this with computer models that indicate exactly how high the levees should be. We are working on about 700 kilometres of levees.

Flood control

We are creating a total of 30 flood control areas in Flanders. Together, they cover more than 2,750 hectares and can store 85 billion litres of water. These areas give rivers more room to flow and flood and temporarily collect water when water levels get dangerously high. This is how they prevent flooding.

Avoiding flooding

By depoldering certain areas, we give rivers more flood space. First, we build a new levee inland, and then we breach the old one. This allows water to flow into the depoldered area. That type of water is less powerful, which reduces the risk of flooding.

Preparing for climate change

In 2005, the Sigma Plan received its first update in response to climate change and the associated extreme weather events and rising sea levels. Now we are working on Sigma Plan 2.0. We consider what interventions are needed in each area to create a safe environment.