Abstract The Riou Chanal is one of the first torrents in France to have undergone corrective measures (1863-1914). Today, its regulatory system is extensively damaged. Authorities are worried by this situation because the village of Uvernet is constructed entirely on this tor- renťs alluvial fan. The purpose of a survey commissioned by the Service de Restauration des Terrains en Montagne has been to assess this threat. This survey is based on historical records, an inventory of damages undergone by works of torrent correction, and a geo- morphological approach involved in defining potential areas contributing to the supply of debris flow. The study shows that instability is extensive throughout this catchment area, but the risk of overflow across the alluvial fan remains limited. This diagnosis is based on two essential arguments: a) the channel is confined by steep banks, ca. 5 m deep, on the alluvial fan; b) the longitudinal profile encourages mechanisms of load substitution and so reduces the debris flow hazard before it reaches the alluvial fan.