VERBUND Innkraftwerke GmbH started the expansion of the existing fish bypass by the Inn power plant in Neuötting in July 2013. The works were completed in December 2013 and the new fish bypass could start doing its job. The fish bypass is 250m long and offers local fish, such as graylings, barbs and nases the chance to bypass the Neuötting power plant. The concept was previously agreed upon by the nature conservation authorities, the local fishing association and by the fishing industry advisory service.
Due to the EU Water Framework Directive, important areas of flowing water in the European Union have to allow fish and other living organisms in the water to pass through. So that crosscut mining constructions such as weirs or power plants can allow fish to pass through, special fish bypasses are needed, which, depending on the regional options available, are either carried out as a purely technical construction or one which is as close to nature as possible.
Fish bypasses mean a new living spaceThe existing fish bypass at the Neuötting VERBUND Inn power plant was rebuilt according to extensive plans, which took into account the newest ecological techniques in order to improve the conditions for the migration of fish in future.
Additionally, the fish bypass was newly connected to the Aubach, which will in future create additional living spaces and spawning grounds for the fish.
Partly technical, partly natural fish bypassesThe roughly 250m long fish bypass is a combination of trough bypass channel with natural stone rows as well as a vertical slot pass made of concrete. The trough bypass channel is roughly 160m long and is made of 40 individual pools lined with stone bars and three still pools. The length of the concrete vertical slot pass is roughly 90m, the slot width is somewhat bigger than 30cm. The individual pools in this section are around three metres long and two metres wide. The flow velocity in the fish ladder is limited to a maximum of 1.5m per second, the annual rate is around 420 litres per second.
Further fish bypasses and renaturation measures on the Inn planned and under constructionAt the Feldkirchen Inn power plant a fish bypass went into operation already in autumn 2013 and in the course of 2014 more will do so with the construction of the fish bypasses at the Teufelsbruck and Gars power plants. By 2015, all VERBUND Innkraftwerke GmbH power plants should be equipped with a suitable fish bypass.
Along with creating ways to allow for fish migration at the power plants, VERBUND Innkraftwerke GmbH will also be implementing measures along the river Inn to connect and revitalise the water areas, which the diverse fish population have as their destination.