[en] Full-text: Slope failures, landslide and settlement of foundation (subsidence) typically do not occur spontaneously. There is a scientific reason for each failure and usually failures do not occur without warning if such sensitive areas are well monitored. It is well known that water is one of the major factors in slope instability that can act to soften the soils and allows the slope failure or foundation to settle. This paper deals with the results obtained from geophysical and isotope hydrology techniques, with the aim on improving the hydrological conceptual model of a landslide-risked site, focusing on the hydraulic connection between water bodies. The increasing interest in using geophysical techniques in hydrogeological studies is because the ability of geophysics to provide spatially distributed models of physical properties in areas that are difficult to sample using conventional hydrological sampling methods. Information gathered from geophysical techniques can be used to differentiate and characterise lithological units and, in some cases, related hydrological properties and processes. The results of geophysical techniques are supported by the isotopic signature which may give a direct insight into the origin and distribution process within the hydrological system. Isotopic measurement was performed on water samples collected from rainwater, river water, stream water, groundwater and tap water. Environmental stable isotopes of water (¹⁸O, ²H) are primarily used in isotope hydrology to identify water bodies of different origins and determine the hydraulic connection between these water bodies. The results from geophysical techniques lead to a hypothesis of a two-layer stratigraphic model which may exhibit different hydrological systems, whereas the results from isotope technique indicated that there is no relation between the groundwater and the tap water. Based on this finding, it could be reasonably assumed that the contribution of flow pathway from a suspected broken water pipeline can be neglected. (author)