The fishway at the Melk power plant on the Danube

The purpose of the measure was to create for fish in the Danube a link between the Wachau section and the upper end or head of the reservoir. This is also where the Ybbs flows into the Danube. Like other Danube tributaries, the Ybbs is a destination for migrating fish, for instance during spawning.  The fishway results in improved conditions for many fish species living in the Danube and the rivers belong to the Natura 2000 “Lower Austrian Alpine Foothills Rivers” region. Rare and endangered species are also benefiting from it. 

  FOTO ALBUM fishway at Melk

No fishway was erected when the power plant went into operation in 1982. Such facilities were included in construction work only in the case of the Freudenau power plant.
The Melk power plant is thus the first power plant on the Danube in Austria to have been retrofitted with a fishway. There is a difference of 12 metres between the water surface level upstream and downstream from the power plant. The second free-flowing course of the Danube in Austria, the Wachau region, is located downstream from the power plant. The Pielach and Melk rivers flow into the Danube below the Melk power plant and above the Erlauf and Ybbs rivers.  

Scheme of power plants and tributaries

Fish migrate along a river, for instance in order to travel from their summer habitat to their wintering grounds. “Spawning migration” is the term used to refer to groups of fish travelling to their spawning grounds.  
Today we know that every domestic fish species travels from one habitat to another over a greater or lesser distance. This is necessary for survival. Obstructions interrupting the flow of the rivers are partly responsible for the decline in previously abundant fish stocks. Such obstructions include dams built as part of power plants.

The fishway is a newly created nature-like channel. It is 2 kilometres long and an average of 12 metres wide. 60.000 cubic metres of excavation material was moved during construction and the bed has been sealed with clay. The river bed has been enhanced using pebbles, rocks and wood. Construction was completed in only 7 months, and the facility went into operation on 5 March 2007.  

Simplyfied Grafic of Melk power plant with fishway (© Andreas Bachmayr)

Enlarged view of the 2 km long fishway (© Andreas Bachmayr)