project in an international consortium in order to establish a hydrogeological model for sustainable groundwater management. In the planned system, geological and hydrological data is combined to a hydrogeological model which predicts groundwater bodies, catchment area and underground flow paths. Users will be provided with a toolkit supporting the acquisition and transformation of various kinds of data into a 3D model. Geological data should be integrated either as 3D volumes or from 2D profiles. The hydrogeological model is based on the geological model but includes additional hydrological information which are necessary to delineate groundwater bodies and sketch groundwater flow-systems. A catchment model is further constructed in a 3D animation by applying principles describing the interaction between surface flow and infiltration into karst. Finally, the calculated model will be displayed in various 3D and 2D views in order to support users in various engineering projects concerning water supply, natural hazards, land planning, renewable energies and underground construction.