SIGMAPLAN ~ Big Pond North

Better protect Flanders against flooding from the Scheldt and its tributaries and restore useful Scheldt nature. That is the starting point of the Sigma plan. In extreme weather conditions, the river can reach a dangerously high water level and even flood. Climate change and sea level rise are only increasing the risk of flooding. Hot summers and desiccation are also part of it.

Low-lying parts of the Scheldt valley are being set up as flood plains and wetlands. In these areas, tidal nature or wet nature develops. The Sigma plan also provides for the local inland relocation of dikes. This gives the river more space. With the Sigma plan, Flanders is working on real climate buffers.

On the other side of the Nete, is the Sigma area 'Grote Vijver'. 

During the construction of the E19, a huge puddle was created between the Dijle and the motorway. This sand extraction pit at the mouth of the Nete and the Dijle gave a boost to nature and grew into a recreational area. Young and old venture here for all kinds of water sports, in lazy periods it is an excellent resting place for water birds. This location is perfect for storing water. We set up the northern part in such a way that freshwater mudflats and salt marshes will develop in the long term. A few times a year it fills up completely. The southern part only floods once every ten to twenty years. That is good news for the water sports enthusiasts, so they get all the space they need and we could invest in floating risers.

At Grote Vijver in Mechelen, we finished the locks of the controlled flood zone last year. Now the final phase of the works has started: we are lowering the Dijledijk to an overflow dike and constructing a compartmentalization dike right through the area. Once these works are completed, Grote Vijver can come into operation as a flood zone and collect excess river water during storm tides. We are aiming for 2021 for this.

Two types of locks

Grote Vijver was equipped with two locks: an inlet and outlet lock in the Netedijk and a drainage lock in the Dijledijk. Both locks play a role in the 'dewatering' (draining) of a flood zone. But the lock in the Netedijk plays an additional role. Every day, a little water flows in and out of the northern part of Grote Vijver, to the rhythm of ebb and flow. This is how mudflats and salt marshes are created. That is a dream living environment for many special animals and plants. You will be able to admire bird splendor similar to that of the Zennegat. Soon to be spotted: the green-legged rider, stilts, dodaars, porcelain grouse ...

LIFE SPARC