Europe's longest fish bypass

Overcoming Barriers: Europe's Longest Fish Migration Path

In early 2015, VERUND began the construction of Austria's longest fish ladder to date at the Ottensheim-Wilhering power plant. A 14.2-km bypass route is being created through the Innbach-Aschach channel, with a water volume provided by the Danube and adapted to the seasons and the natural drainage dynamics of the tributaries. This bypass channel best meets the high ecological and technical requirements for passability for fish. Furthermore, through the near-natural design of the construction with deep areas (pools), fords and inlets, additional habitats for fish and other animals are created. 

The bypass channel itself doesn't lie in a Natura2000 area; however, it represents an important connection between the Natura2000 areas on the Danube and what brings its deposits. Next to the area's network there are important stepping stone biotopes which considerably provide support for the exchange between the populations in the conservation areas.

The inflow construction is located on the right bank of the Danube connection at the beginning of the backwater area of the Ottensheim-Wilhering power plant at a river-km of 2158.4. In order to ensure an investment corresponding to the ecological conditions and to safely direct the flood waters away, it will be fitted with a moveable weir gate. The bypass channel integrates the river sections of the Brandstätter channel, the Aschach bypass channel as well as the one in Innbach. Together with the module "Abwinden-Asten power plant secondary channel at the beginning of the backwater area" a habitat compound has been created here, which is unique on the Danube in Austria in terms of its size and quality.