The groundwater protection zone of Hartkirchen in Upper Austria at the northern edge of the Eferding molasse-basin is going to be rearranged where the river Aschach flows through the Kristallin of the Bohemian Massif into the basin. This theses should give a better understanding of the groundwater situation and the possible interaction of the riverwater with the underground. Mulitelectric-geoelectric profiles and spontaneous potential (SP) measurements were made over the river and a filled arm of the Aschach. In the upper most layer of alluvial deposits of the Aschach valley are water saturated regions (50-250 Ohmm). They are accompanying groundwater flows of the Aschach. The river is clearly separated from the underground, which means, that due to the clogging the river water cant get into the underground. The non-water-saturated alluvial deposits (100-400 Ohmm ) have a thickness of 10 m. The sediments of the molasse-basin, Linzer Sande with 100 to 450 Ohmm and Schlier with <100 Ohmm and a thickness of 30 m, are only recognised in the south. As the spectrums of the resistivities of the Molasse sediments and the Kristallin overlap, it is not possible to distinguish them explicitly. Due to a fault system the Kristallin has a distinct relief and shows a wide spectrum of resistivity (350-1700 Ohmm). There are no evidences of an infiltration of the riverwater into the underground. The SP show a groundwater-flow within the alluvial deposits and in the filled part of the Aschac