During the 2021 floods in North-West Europe, the Vesdre was the most severely affected river in Belgium. Since then, several actions have been undertaken, which offer opportunities for promoting Nature-based Solutions (NbS). One of them is a masterplan for resilient spatial planning across the catchment. While this masterplan promotes a broad range of NbS, it lacks a quantitative assessment of their impact. The purpose of this pilot study is to employ hydrological and hydrodynamic modelling to assess potential impacts of these NbS on the river system.

The modelling system Wolf, which includes modules for rainfall-runoff, flow routing, inundation, and impact analysis (estimation flood damage and monetary losses), will be applied to quantify the effects of the proposed NbS in the Vesdre catchment. Models will simulate the effects of NbS, aiming at giving more room to the river in several pilot study sites. The model outcomes will be quantitative indicators of direct use for cost-benefit and multi-criteria analyses. This will prove valuable to unlock approval and funding of measures. Visuals extracted from the models will support impactful communication on the effects of NbS. 

The pilot aims to predict and demonstrate the relative effectiveness of various NbS compared to traditional ‘grey’ solutions. This research will contribute to bridge the gap between conceptual ideas, as found in the master plan, and the actual needs of decision-makers. Furthermore, the research will contribute to standardization of NbS, and the creation of training and learning materials to accelerate a faster uptake of NbS in river systems.