In addition to interrupting or disturbing the longitudinal continuum for the migration of aquatic organisms, run-of-river plants plants also represent significant impacts for the sediment transport in a river.
In the following paper, general aspects of changes and disturbances in sediment dynamics due to the operation of hydropower plants are explained.
The aim of this work is to reveal the ecological significance of sediments and freshwater-morphological structures in the vicinity of small hydropower plants. Referring to this, we describe the technical efforts (measurements and modeling) required for the planning of river engineering measures, and we further address detailed possibilities for near-natural/technical optimization.
Above all, we discuss the possibilities for self-forming gravel spawning habitats in the vicinity of hydroelectric plants in detail. The various forms of salmonid spawning sites, which were validated in the course of extensive fieldwork, show that reproduction sites could evolve even in areas influenced by small hydropower plants.
Moreover, by mapping spawning redds of brown trout trout and rainbow trout, the importance of structural improvements at small hydropower plants is integrated into the discussion on future, ecologically oriented improvement hydraulic engineering measures.