Scaldwin

ScaldWin is a European project that aims to re-naturalize boundary rivers by removing obstacles (dams) and improving the hydrological regime of the water, to render possible the return of different species of fishes. The Molenbeek River has been chosen as one of the cases study.

The Molenbeek River runs SW-NE, from the outskirts of Brussels in Dilbeek to Jette, where it goes into the sewer network. The river is composed by 4 km of open streams while 2 km of its section consists of pipes and ducts. The catchment of about 20 km2 includes urbanized areas and open spaces where the city is now spreading: 50% of the area is less than 25% impervious, while the rural and natural landscapes account for about 10 % of the total area.

Urbanization puts a lot of pressure on the environment and leads to growing problems in water management (such as flooding, saturation of the sewer network...). That is why the re-naturalization project of the Molenbeek River takes into account the whole catchment. For its sustainable management, it is essential to understand and assess the different factors, which contribute to the balance of this heterogeneous environment.

We are working to bring to the study the following elements:

• A better understanding of the geological and hydrological context of the catchment area;
• Quantification and the protection of the river base flow;
• The quantification of the inputs and the outputs of water inside the catchment area;
• Projection of potential floods;
• The assessment of the different water fluxes: potential leakages of waste water in the aquifers, potential infiltration of meteoric waters (groundwater, runoff) inside the sewer network, river/sewage mixing, etc.

The study is based on the collection and projection of environmental data (topography, urbanization, geology, urban planning...) for the whole catchment, and on the use of the stable isotopes of water as tracers to quantify the different urban water fluxes (sewage, groundwater, runoff ...). The samples are analyzed at the Vrije Universiteit Brussel (VUB) with the mass spectrometer in our laboratory.

The project has started in 2009 and will end in 2013.

For more information about the ScaldWin project, click here.