Abstract
The 31st of March 1997 a debris flow seriously affected the quebrada La Comunidad and. Morpho-hydro-climatic studies done after this event showed that extreme rainfall storms was the main factor to explain these phenomenons, it is evident that the morphology of the catchment, and particularly the longitudinal profile, played a fundamental part in the generation of debris flows. These events seem preferentially take place in the small catchments, therefore they can be considered as more dangerous than the big ones for the town suburban zones.