Restoring River Connectivity in Line with European Legislation

Abstract

Abstract Water Framework Directive defines the river longitudinal continuity as “undisturbed migration of aquatic organisms and sediment transport”. Electrical energy production from hydro sources is the main risk that generates hydromorphological alteration of surface waters by disconnecting the rivers. The flow reduction on the river sector from the water intake to the restitution point of the small hydropower plant is also considered as a hydromorphological alteration that can modify the natural hydrological regime. This paper presents good practices for ensuring the river longitudinal connectivity while Small Hydropower Plants are implemented. In order to restore the river longitudinal connectivity for fish migration, some types of fish passages used within the hydropower facilities from Europe are presented and discussed. The recommended solutions are important to mitigate the small hydropower plants’ negative effects on river ecosystems and it can contribute to the increase of energy power units based on renewables.