Successful development of a geothermal system requires reliable information on its permeability and fluid pathways, which can be fault-controlled and/or influenced by the lateral extent of its reservoir rocks. Utilisation of implicit 3-D visualisation and modelling software allows complex geological and structural framework models to be established that support exploration, and help constrain borehole-targeting with reduced drilling risk and cost. The ability to model geology in a 3-D interface has provided new insights regarding the geological framework, controls on deep-seated permeability, volcanic and basement stratigraphic correlations, and geothermal system evolution in a case study from Kawerau, New Zealand. (C) 2014 Elsevier Ltd. All rights reserved.