ABSTRACT

By decreasing the flow velocity and turbulence, reservoirs controlled by dam are likely to force inflowing sediments to settle. This process can be more or less temporal and intensive, depending on particle size and reservoir characteristics (Morris & Fan 1997). To limit the reservoir sedimentation and prevent a disruption of sediment continuity, one possible option for dam operators is to recover favorable flow conditions either for routing inflowing sediments or remobilize previous deposits (Kantoush & Sumi 2010). In the case of cohesive sediments, one of the main challenges to deal with is that deposition and erosion thresholds are often radically different as a result of deposit consolidation (van Rijn 1993). The purpose of this communication is to present the methodology followed to define those conditions in the case of the Champagneux dam.