In order to define the safety conditions and the sustainable development of the large Triesenberg landslide (5 km(2)), the Principality of Liechtenstein has undertaken a modelling research to determine both the critical hydraulic heads and the potential influence of climate changes. The main objectives of this research focused on critical groundwater levels and related movements, in order to supply significant mid and long-term information for land planning. First a geological model was built to define the parameter fields; then a transient unsaturated hydrogeological model computed the groundwater pressure fields that were introduced in the geomechanical model. The results of this three stage 3-D modelling process show a moderate variation of the slide movements when considering climate change scenarios, as the progressive snowmelt, due to more rain events in winter, will absorb the present critical pressure peaks.