This paper focuses on the hydro(geo)logical temporal behaviour of deep-seated earthflows developed in clay-shales of Southeast France. These landslides experience a remarkable seasonal kinematical trend, controlled by ground water recharge and rain-fall. The first part of the manuscript discusses the data necessary to acquire to build a concept for the hydrological behaviour of earth-flows. The second part focuses on the implementation of this concept in a hydrological model, and discusses its calibration and validation. A coupled unsaturated/saturated model, incorporating Darcian saturated flow, fissure flow and meltwater flow has been developed to represent the landslide hydrology. The conceptual model is formalized in a 2.5-D physically-based and spatially distributed scheme. The model is calibrated and validated on the multi-parameters database acquired on the site since 1996. The complex time-dependent and three-dimensional groundwater regime is well described, on both short- and long-term. Once calibrated, the model can be used to simulate the landslide hydrological behaviour in real or hypothetical situations and help to predict future scenarios based on environmental change.