The aim of this Master thesis is the determination of water contents within landfills as well as the monitoring of water flow paths during a focused irrigation. For this purpose, the geoelectrical measuring method (ERT - electrical resistivity tomography) was chosen. The first part of the measurements was performed at the area of the paleomagnetic laboratory of the “Montanuniversität Leoben” in Gams. Due to the knowledge of the composition of the subsurface, it is ideal for the measurements. By means of these measurements, the optimal electrode and measuring system parameter configuration could be determined, which was used during the measurements at the Rautenweg landfill. There, the purpose was to identify the original task, namely the determination of water content and the traceability of water flow paths. The results from Gams indicate that the Wenner electrode configuration is the most suitable. Also, the original objectives of this Master's thesis could be determined by means of measurements at the Rautenweg landfill, with some restrictions. These limitations provided further findings in the importance of various factors influencing the qualitative determination of water contents and water flow paths for prospective projects. Therefore, knowledge about the temperature and conductivity within landfills, the presence of in-situ waste samples, and a sufficiently large difference between the conductivity of the landfill body and the introduced water, is essential.