Landslides are notorious in Colombia due to the rough topography and tropical rainfall conditions and thus are a major hazard in many regions of the country (Huggel et al., 2010). The Combeima region is a landslide prone area. Indeed, in the past, hundreds of victims and huge damages occurred. In June 2006 multiple slope failures and landslides destroyed major parts of population centres. To mitigate the risk to life caused by landslides, a pilot LEWS has been designed and implemented thanks to a project funded by the Swiss Agency for Development and Cooperation (SDC) (Huggel, et al., 2008). Daily rainfall data were analysed up to 30 days before a landslide occurrence and cumulative-duration thresholds have been defined. Anyway due to a lack of landslide (only about 20 landslide events) data (Terlien, 1998), the thresholds used were principally based on statistical analysis on rainfall. In order to further reduce the uncertainties, the rainfall stations were equipped with geophones and local observers report potentially landslide-producing situations (Huggel et al., 2008, 2010). Rainfall and geophone measurements are transmitted in real-time to the Regional Emergency Committee of Tolima (CREPAD), where, through an emergency protocol, the different warning levels are defined and the corresponding actions taken.