Torrents are very sensitive to changes in climatic and environmental conditions. In this paper, the background and the basis of a project which analyses the hydrological and geomorphological processes in this type of watersheds are discussed. The two test areas, Spissibach at Leissigen (Berne) and Rotenbach at Schwarzsee (Freiburg), are described and first results of the hydrological and geomorphological investigations are presented: The significance of the storage conditions for flood generation are studied with the BROOK-model. The so-called topoindex of the TOPMODEL allows a physically significant spatial differentiation of the contribution areas.