Traffic jams

Dams are sections in watercourses, where the water level is increased compared to the natural state due to human uses (mainly hydropower, but also water discharge for other purposes and insulation stabilisation measures) and thus the flow rate is reduced. This is achieved by transverse structures (cross elements such as weirs, ramps, dams). In dams, the composition of the bottom substrate and its colonisation by soil-based aquatic organisms and the composition of fish species change due to the reduced flow rates. Dams, depending on their length and depth, have more or less negative effects on the ecological status of the river. The data state is in line with the 2015 National Water Management Plan (NGP) and will be updated following the publication of the NGP 2021.