Together with the VLM, VMM, KU Leuven and Regional Landscape Haspengouw & Voeren, we set up a local Living Lab to accelerate the implementation in practice of sponge measures in the Herk & Mombeek valley. How do we maximise water retention in the landscape to prevent drought and flooding as much as possible? How do we achieve this not only in our streams, but also in our villages, our agriculture and our nature? Over the next year and a half, we will work with a valley-wide coalition on an implementation-based sponge action programme!
The Herk and Mombeek valley is a sub-basin of the Demer basin and is also called the 'roof' of the Demer due to its upstream location. In the summer of 2021, rain caused several floods in the Herk and Mombeek valley, and by extension in the Demer basin, and it is clear that without further action, this situation could be repeated. Besides measures in lower-lying parts of the area, it necessitates interventions in the higher-lying areas too: the overly rapid runoff of water results in erosion, but also increases the risk of flooding. Drought has also caused damage in this sub-basin on several occasions, with ponds already dry in February and fruit growers and farmers on the upstream banks suffering from declining crop yields due to drought. Furthermore, it is an economically challenging period for the fruit-growing sector and more profitable alternatives are being sought, especially for apple growing, resulting in orchards being uprooted and ploughed.
Resisting these and greater challenges in the future will require restoring the natural landscape and water system of the Herk and Mombeek rivers. To this end, the Living Lab can rely on an active regional coalition, led by Regional Landscape Haspengouw and Voeren and the Demer basin coordinator, who have already rolled out lots of measures. The Living Lab aims to build up sufficient scientific and practical expertise on source measures in nature, agriculture and urbanised or mixed land, which is currently unknown territory. By collaborating with design research and impact modelling, we can identify the critical points in the valley and confront the various site managers with the climate reality of the future. This will provide the local coalition with insight into the goals to be achieved in their specific areas. Within the region, coalition members and other local organisations must mutually agree on which risks they do and do not deem acceptable. This requires a socially innovative process that does not shy away from the tough questions: do we find it more acceptable for ten houses to have their basements flooded, or for a farmer to lose his entire crop? Do we flood the village centre or the valuable historic grasslands? Depending on the risks, several scenarios offering potential solutions will be proposed and calculated, which in turn will be democratically tabled for discussion. This will allow the regional coalition to make choices according to the realities on the ground and with greater certainty about the effectiveness of the measures.
This Living Lab is one of four water+land+scape coalitions that want to experiment with the impact of source-based measures on their sub-basins. The other areas are the Getestreek, the upper course of the Yser and the area between Kortrijk and Roeselare. The experience acquired during this Living Lab will be applied to these other basins and Flemish policy. Moreover, the Herk & Mombeek Living Lab has been selected as a Water-Oriented Living Lab by Water Europe, which could provide international learning opportunities.
This Living Lab was set up thanks to a cooperation partnership between Architecture Workroom Brussels, the Flemish Land Agency, the Flemish Environment Agency, Regional Landscape Haspengouw & Voeren and KU Leuven.