Integrated sediment management of alpine rivers

Sediment management of alpine rivers is crucial to ensure sustainable hydropower production. Dams inhibit not only biological consistency but also drastically restrain natural sediment dynamics. Upstream of the dam, coarse material is accumulated, leading to a progressive sedimentation of the reservoir. This causes a reduction in the effective water head and can even lead to the blockage of lowerlying operation organs. Downstream of the dam, reduced flow velocities promote the settling of suspended sediments, causing the clogging of open pore spaces in the bed material that naturally serve as fish spawning ground. The lack of coarse sediment also provokes extended streambank erosion and the channeling of the river, leading to a less altered river morphology and reduced living space for a large biodiversity. An integrated sediment management helps to optimize ecological, economic and social effects linked to hydropower.