Aim of the work was a mapping in combination with microfacial, biostratigraphic, tectonic and diagenetic investigations for a better hydrogeological evaluation in the western Koschuta (Karavanke Mountains). The area can be subdivided in several tectonic units with sedimentary successions of different palaeogeographic provenance. First unit: Goggauer Kalk (Lower Permian), Gröden Formation (Middle Permian), Bellerophon Formation (Upper Permian), Werfen Formation (Early Triassic), Gutenstein Formation (Lower Anisian), Steinalm Formation (Pelsonian). Onto postpelsonian palaeohighs the Contrin (Illyrian) and the Schlern Formations (Upper Ladinian-Lower Carnian) were deposited. In the basin mass-flows, volcanics and carbonates of the Loibl, Reiflinger, Buchenstein and Raminger Formations deposited until the Upper Ladinian. The second unit contains the Waxeneck Formation (Upper Carnian) and the third unit the Dachsteinkalk Formation (Norian). Sinistral NNE-SSW and dextral WNW-ESE directions of strike-slip movement can be distinguished. The main water flow follows along NNE-SSW, WNW-ESE, NE-SW and NW-SE striking faults and joints. A young NE-SW fault is crosscutting the older, impermeable main southern Koschuta fault. In case of this reason the source areas of the Hainschbauern- and Koschutniksprings are overlapping.