This project is aimed at examining the hydrological and hydrogeological situation of the planned extension area of the Dachstein-limestone quarry of Gmunden Zement Produktions- und Handels GmbH near the village of Ebensee. For this purpose two complementary approaches were used: the use of hydrogeological field methods, like field mapping, field measurements and interpretation of this data; and the application of specialised software packages to estimate a more contemporary and holistic solution to hydrogeological problems in karst systems, especially water yield and temporal interrelation. The software packages Surfer (Golden Software), WMS (Environmental Modeling Systems, Inc.) and ZemoKoSt (Bundesamt und Forschungszentrum für Wald) were utilised to model the natural situation in the extension area. The results allow to simulate the areas natural water balance resulting in predictions of possible changes in the water balance due to the human interference by quarrying. The impacts were best represented using the Excel-based model ZemoKoSt, which is a modified flood routing model for small alpine catchments (torrents). Due to the lack of data the model WMS could not provide additional results. Still, this software package can be considered useful, even based on little data, for doing basic hydrogeological analyses like calculating the orographical catchment.