In order to better understand the risks associated with torrential floods in the Grenobloise region, a precise assessment of hydrology, hydraulics and morphodynamics is desired by Grenoble-Alpes Métropole. These torrential phenomena are sometimes destructive because they are extremely charged with solid material. The HYDRODEMO project aims to fill a critical lack of knowledge about this type of hazard, first by characterising the hydrology of “control” watersheds representative of the different massifs around Grenoble (Belledonne, Chartreuse, Vercors) and torrential tributaries of the territory, then by defining a methodology for transposition to the other catchment areas of the territory. The various actions (hydrological modelling on instrumented watersheds, characterisation of rain events causing floods, characterisation of the solid transport of torrents according to a typology of watersheds) should allow the development of a methodology for characterising hydrology and estimating sediment production applicable to all watersheds in the territory. This new scientific knowledge, brought by the future INRAE INRAE in partnership with the CNRS, will in the future better understand the phenomena associated with torrential hazards, better prevent them and improve alert to the population.