Return drainage in the city

Return drainage in the heart of Dendermonde

Return drainage is still a relatively unused way of working within the construction industry. It requires an additional investment and often takes extra time. For these reasons, it is therefore often avoided by construction companies. However, it is a crucial step in the quest for a circular economy that takes care of raw materials such as water and energy.

On the Oude Vest in Dendermonde, a multifunctional complex is being built by Hof Van Saeys and Uplace. Under the complex there will be a car park with two underground levels and nine lift shafts. A realisation that will release a lot of groundwater that has to be pumped out of the building pit. Because of the subsoil's susceptibility to settlement and the nearby abbey garden, the drainage will be carried out within water-retaining walls.

In order to help build a circular economy, a system of 22 underwater pumps is used to pump the groundwater from the construction pit to 22 above-ground return wells. These were strategically placed just behind the water-inhibiting walls. Where underground water is normally pumped into the sewer system, these return wells send it back into the ground. This way, there is no loss of groundwater due to the construction project.