Oberaudorf-Ebbs Run-of-River Power Plant

VERBUND's Oberaudorf-Ebbs power plant is a run-of-river power plant on the Inn River, north of the town of Kufstein between the municipalities of Ebbs (Tyrol) and Oberaudorf (Bavaria).

Technical Description 

The border power plant of Oberaudorf-Ebbs was built between 1988 and 1992 and is for the time being, the biggest hydropower plant on the river Inn. The power plant was built using dry construction techniques in a construction pit erected originally on the Inn riverbed. The facility was conceived to be what is called a pier power station, made up of three weir fields and two machine columns. In both machine columns, there is a Kaplan bulb turbine with a horizontal shaft and a built-in three-phase electricity generator. In this way around 268 GWh of electricity are generated on average every year. Moreover, currently there is a fish ladder being built.

Fish bypass secures passability and living space 

In 2013, VERBUND began the construction of just such a new fish bypass at the Oberaudorf-Ebbs power plant. It is divided into three sections and is located on the Austrian side of the Inn River. The underwater connection is made over a natural pond, stretches over the remodelled drain channel as a natural body of water, and leads over a vertical slot pass to the exit into the estuary region of the Jennbach and the Inn. In this way, voyaging fish and aquatic creatures find their way from the lower reaches to the section of water above the power plant. 

The new fish bypass spans a total height of around 12.5 metres from downstream of the power plant to the headwater with the help of three different types of construction. Entrance downstream takes place over a natural pond pass, and the bypass subsequently proceeds over a natural channel. The last hurdle is overcome in the form of a vertical slot pass. In the top exit structure, a self-operating valve ensures a constant volume of outward flow. A minimum of 1,000 litres per second flows through the entire migration channel, reaching up to 3,000 litres per second during the high-flow summer months. A self-operating pump system takes care of the maintenance measures in the vertical slot pass, to ensure a constant flow of 60 litres per second so that the system does not dry out. 

The new fish bypass not only provides for the traversability of the river, but also creates new habitats. With it, aquatic creatures gain additional space for the search for food, reproduction, and retreat during a flood. In this way, these measures contribute significantly to the preservation and improvement of the fish population of the Inn.