The aim of this paper is to discuss a catchment-wide approach for analysing the sediment regime with respect to reservoir sedimentation, based on the Alpine Solk-basin in Austria. On a scaling perspective the boundary conditions and major processes of a catchment, like the geomorphological setting, are given by longterm developments. On the basis of field mapping these effects are discussed with respect to sediment availability, being affected e.g. by deep-seated gravitational slope deformations and slope creeping. Within these longterm processes, short-term unsteady sediment supply, erosion, transfer, deposition and remobilisation processes determine reservoir sedimentation and management. An intensive field monitoring program, including bedload and suspended sediment measurements, supplies data for the subsequent rainfall-runoff-erosion and sediment transport modeling (input, calibration and validation data). Instead of aiming to predict sediment transport processes in a purely deterministic manner the use of stochastic concepts allows to define locations in the catchment with a high probability for delivering significant amounts of sediments to the channels and finally the reservoir. Results show that landuse, channel regulation and avalanches are of great importance for sediment supply and that catchment management (beside managing the reservoir itself)has to address these.