A centralised GIS platform for inland waterway management in Wallonia
Type:
Presented during:
CEDA Dredging Days 2026
Authors:
P. Dierickx, M.-S. Hugot, C. Louis and N. Strivay
Abstract
Efficient dredging operations are essential for maintaining navigability on inland waterways. In Wallonia, a legacy of industrial contamination has significantly complicated the management of dredging operations. Strict environmental legislation now classifies dredged sediments as waste. Depending on the chemical properties identified on site, they must be transported to appropriate treatment centres, sometimes far from the deposits, resulting in high transportation costs. At the same time, annual public budgets are relatively fixed and must remain under control. In addition, the immediate environment of areas to be dredged must be systematically analysed to avoid risks such as bank subsidence. It was therefore necessary to adopt a policy of surgical dredging, supported by accurate management tools capable of prioritising intervention zones and optimising total costs across the full chain from extraction to destination. To that end, the Wallonia Public Service Mobility&Infrastructure (SPW) relies on HydroWalMap, a centralised GIS platform developed by G-Tec. The platform brings together diverse datasets into a single, consistent environment, including bathymetric and LiDAR surveys, sediment quality assessments, and georeferenced photographs. Originally focused on dredging, the platform has grown over time to address broader waterway management challenges such as dam siltation, bank erosion, and public domain management. These challenges, increasingly driven by climate change, add to the complexity and cost of waterway maintenance and call for integrated, data-driven solutions. Built-in analytical tools cover the full range of operational needs, from dredging management and navigation verification to bank inspection and flood assessment. With over 200 users ranging from field agents to project engineers, the platform supports coordination across internal units and facilitates communication with external partners such as universities and dredging companies. By enabling surgical dredging, it contributes directly to cost control, with final costs per cubic metre ranging from €100 to €200 depending on sediment contamination levels.