oa Mar In Flanders (belgium): Site Selection

In Flanders, households, industry, energy and agriculture consume significant amounts of water. As a consequence of the high population density, the water availability is rather low. This causes an imbalance between water demand and water availability. To protect groundwater resources for public water and to prepare for prospective water shortages in relation to changing climate scenarios, De Watergroep, a Flemish water company, aims to improve its water management. To evaluate the possibility for the application of Managed Aquifer Recharge (MAR) techniques in Flanders, a literature study on existing MAR applications in Flanders was carried out, followed by a detailed screening of 1) potential aquifers and 2) water production sites of De Watergroep. According to the literature study, only at 2 waterproduction facilities in Flanders (i.e. St. André1 and Grobbendonk2) MAR techniques have been implemented by means of infiltration ponds. Rapid screening of the potential for MAR for existing water production facilities indicates that MAR techniques using temporary water storage in a riverbed (e.g. percolation tanks, underground dams, sand dams, recharge releases) are not relevant. In Flanders rivers drain the water table which is connected to the surface water level and, in contrast to arid regions, the rivers contain water permanently. The only feasible MAR techniques for Flanders are infiltration basins, riverbank infiltration and injection techniques. According to the geohydrological context of aquifers at water production facilities, the geochemical composition of the raw water, the presence of an industrial water softening plant, and additional water resources, it was concluded that: *infiltration or injection, in unconfined aquifers is in general not a plausible option, because of the high groundwater level, the low storage capacity and the limited aquifer thickness (<25 m). *deep infiltration or injection in unconfined aquifers can be considered at locations characterised by positive relief forms. These areas however, are characterised by iron-bearing deposits enhancing the risk of iron precipitation and well clogging. *the aquifers characterised by optimum geohydrologic conditions with respect to aquifer thickness (50 m), hydraulic conductivities (30 - 40 m/d) and specific yield (40 - 60 m³/h/m) are not considered, because in the respective area there is no need for additional water storage. Finally, out of 78 water production facilities, for 2 sites with favorable conditions a conceptual model for the application of AS(T)R has been worked out (Table 1). Depending on further modelling results a pilot test will be worked out. Since Qatar faces significant increases in peak water demand due to its growth in population, industrial activities and the organization of sport events such as the 2022 FIFA World Cup Football, the evaluation and implementation of MAR techniques is essential to assure the required drinking water production. A similar approach as applied for Flanders, i.e. evaluation of applicable MAR techniques, screening of potential aquifers and design of a conceptual model is recommended. References 1.Van Houtte E. et al. (2012) 2.Feyen J. (2001)