Hydrological precision work in the Mangelbeek valley

Investigate and optimize the operation of six pumping installations that have been pumping water away for years in the subsidence area in Heuden-Zolder. That is the task of the VLM as a partner in the European Interreg project Green WIN. We hope that there will be less pumping in the future as a result. Collecting more water and allowing it to penetrate into the soil would also benefit nature in the Mangelbeek valley. At the same time, there must be sufficient water for agriculture, and flooding for the residents must be avoided. Stan Forier, project leader, talks about the hydrological precision work we are doing in the Mangelbeek valley as part of Green WIN.

What exactly does the Green WIN project entail?

Green WIN is a North-West European Interreg project that aims to reduce energy consumption and greenhouse gas emissions from pumping installations at water managers.

Within the project, the partners are investigating how they can reduce the CO2 emissions of the pumps. They look at which technical interventions they can carry out, how they can use the pumps more efficiently and how they can optimize the water management.

As a partner, VLM is actually an outsider in this project. After all, we are not a water manager or conduct research on pumping installations. Why did we get involved in this project and what does VLM use the European resources for?

The VLM is a partner in Green WIN through the land development plan Mijn Mangelbeek in Heusden-Zolder.

In this land development plan we want to improve, among other things, the water management and water management of the mine subsidence area in Zolder. Six pumping installations have ensured for decades that the water does not cause any nuisance to residents and farmers. These pumps are included as a case study in the Green WIN project. We can then reuse the knowledge we build up through Green WIN in future land use plans. After all, the mine subsidence problem occurs in several stream valleys of De Wijers.

What exactly are you researching?

We want to see whether the pumping operation in the Mangelbeek valley can be made more ecologically and cheaply. We want to adapt water management in such a way that in the future there will be less pumping, or even better, that pumping can even be avoided in some places. As a result, we ensure a smaller ecological footprint of the pumps. After all, the pumps in the area are old and energy-consuming. In addition, these measures ensure that the effects of climate change are reduced. By pumping less, wetting occurs. In this way we also realize additional wet nature in the valley in one movement, where water can be collected and infiltrated into the soil.

How do you handle this?

Many archives were lost when the coal mine was closed, so we have little information about the operation of the pumps and the interventions that took place in the past on the streams and canals in the Mangelbeek valley. That is why, together with the province of Limburg, we are investigating the state of groundwater in the Mangelbeek valley in Zolder and what the effects are on the nature in the valley. For example, we look at how deep the groundwater is and how it varies throughout the year.

What are the results of the investigation?

The measurements show that the groundwater is too deep in some places and that the environment is drying up. In other places the water is above ground level again and there is flooding.

In many places, this means that nature cannot develop properly.

What can be done about it?

We examined a number of scenarios in which we looked at what effects a number of proposed interventions would have on the groundwater and on the environment. So not only for nature but also for the residents. After all, it is crucial that local residents do not experience flooding.

Can you give an example of such a scenario?

In one of the pumping stations, groundwater is pumped up from one very deep well. The research now shows that if we were to replace that deep well by digging four less deep wells, spread around the current location, up to 75% less water would have to be pumped up to achieve the same effect. That already saves a lot of energy, but there is more. The current pump water is now discharged into the sewer. We can use that water much better to provide better, wetter conditions in a nearby nature reserve. After all, sampling has shown that the quality of the pump water is good. This enables us to look for ways to reuse this water. That is very good news.

Are there any options that can be addressed after the investigation?

Sure. Another pumping station was built long ago to combat flooded gardens and farmland. We have now seen that this pumping station pumps the surrounding area too dry. Adjustments to the pumping regime and the canals in the area can provide some relief here.
We can also create a win-win situation with the water that has been pumped away. Now that water still ends up directly in the Mangelbeek. It would be better for this to infiltrate the soil on a plot further away and at the same time make an old dry castle moat water-bearing again. This provides both ecological benefits and a nice extra for recreation and heritage in the area.

These examples show that interventions are often thought of as part of solutions for the drought and water shortage in the summer period.

Yes that's right. In this way, the Green WIN project fits in well with Minister Demir's Blue Deal plan.

More info

Watch the interview with project leader Stan Forier .

If you want more information about the Green WIN project, watch this video:

https://www.youtube.com/watch?v=aASkH5S81dY

Or surf to the website: https://www.nweurope.eu/projects/project-search/greenwin-greener-waterway-infrastructure/