Using three-dimensional geological mapping methods to inform sustainable groundwater development in a volcanic landscape, Victoria, Australia

This study investigated the use of three-dimensional (3D) geological methods to provide better groundwater resource estimates for the Spring Hill area in central Victoria, Australia. Geological data were gathered in 3D geological software, which was utilised to derive fundamental dimensional parameters of the groundwater system in the study area. Mining industry software and hydrogeological methods were combined to give volumetric determinations of the basalt aquifer that were used to improve estimates of the groundwater resource. The methods reduce uncertainty about the physical attributes of the aquifer systems and greatly improve conceptual understanding of their behaviour. A simple numerical water-balance model was developed to refine the estimates of aquifer volume and fluxes to approximate observed water-level behaviour in the area. This enabled a much better comparison of groundwater resource use to the natural inputs and outputs for the area. A key conclusion was that the main issues for sustainable development and use in the study area are more to do with the physical aspects of the aquifer system, rather than simply the volume of water pumped. Visualisations of the area’s hydrogeology also provide improved hydrogeological understanding and communication for groundwater users and administrators.