Blue Deal
Nature-positive remeandering helps prevent flooding
The Aa river now meanders again through the Graafweide-Schupleer nature reserve in Vorselaar and Grobbendonk. Thanks to the Vlaamse Milieumaatschappij (VMM), seven old meanders have been reconnected to the original watercourse.
This project benefits both water safety and the ecological value of the area. Sweco was commissioned by the VMM to handle the preliminary design, permits, and tender dossier.
- Client
- Vlaamse Milieumaatschappij
- Location
- Vorselaar and Grobbendonk
- Expertise
- Preliminary design, permits, and tender dossier
- Stakeholders
- Vlaamse Landmaatschappij, Agentschap voor Natuur en Bos, and Natuurpunt
A longer Aa means less risk of flooding. In the past, the Aa was straightened, which increased the risk of flooding. Now the river is 250 meters longer and has more buffer capacity. Additionally, the wet nature around the river provides extra buffer space, reducing the likelihood of the Aa overflowing its banks. Moreover, it now flows more slowly, preventing drying out during dry periods.
Better water storage and wet nature
“With these new meanders, we are taking another important step forward in the necessary restoration of the valley. Projects like these increase water security: they better protect us against flooding and help us bridge periods of drought. And we achieve crucial ecological goals with them.”
Cathy Berx, Governor of Antwerp
In addition to structural restoration, we also carried out some smaller interventions such as breaking up pipes, excavating riverbanks, and creating breaches in the riverbanks. This ensures a gradual transition between the Aa and the adjacent plots. This way, the valley can better store water and wet nature can develop.
Space for water, better resistance to drought
With its straightened structure, the Aa river had become very sensitive to the changing climate. The chances of it drying out or overflowing increased. Efforts were needed to make the Aa healthier. The Graafweide-Schupleer nature reserve, through which the Aa flows, with its distinctly wet and open character and valuable swamp forests, is an area where ecological restoration has a significant impact.
In 2024-2025, several old meanders were reconnected to the Aa. The Aa in Graafweide-Schupleer thus became 250 meters longer. Water now has the space it needs. The current course was filled in with the soil that was freed up by excavating the meanders. No soil needed to be brought in or removed for this. However, a dump was discovered during the execution at the most downstream meander. Additionally, the enriched top layer was excavated locally, and the original ground level was restored. For these matters, some soil was removed.
“We come from a time when draining water as quickly as possible was the only right course. The increase in drought periods and periods of heavy rainfall due to climate change forces us to think more integrally: Let nature handle its whims. This remeandering project is a beautiful example of that. Meanders ensure that water flows more slowly and causes less damage in residential areas downstream. At the same time, the meanders also slightly raise the groundwater level.”
Jo Brouns, Flemish Minister of Environment and Agriculture
Ecological boost for fauna and flora
The remeandering of the Aa is part of a larger project. Previously, new meanders were added to the Kleine Nete in Olen and Herentals. The Molenbeek-Bollaak in Ranst was also tackled. Sweco also handled the study (design, environmental permit application, tender) of these projects.
More meandering is also good for nature. The bends create more variation in the flow, allowing for more diversity. You give more space to the water, which provides better growing conditions for plants. There are also better spawning conditions for fish.
The broader (water) framework
The VMM carried out the works in collaboration with the Vlaamse Landmaatschappij (VLM), the Agentschap voor Natuur en Bos (ANB), and Natuurpunt as the owner of the area. The structural restoration contributes to the VLM’s Nature Development Project, which aims to create 150 hectares of additional wet nature in Graafweide-Schupleer.
In combination with this project, Aquafin has realized a new stormwater basin, pumping station, and pressure pipelines to the wastewater treatment plant (WWTP) at the current pumping station. This significantly reduces the overflow of the sewer system into the Aa, improving water quality and making the remeandering project more effective.
