Picture: Lechwerke AG
In front of the ODK Kraftwerk Oberelchingen, which is operated by the Bavarian Elektrizitätswerke, the Danube is 250 meters wide. Within the pilot project INADAR, the dam in Elchingen will be improved in terms of ecology on a length of 500 meters, ,.The initiative s co-funded by the European Union. The result is a nature like river bank.
Water in the middle, earth and concrete on the left and right side: That’s how the Danube currently looks at the power plant Elchingen. Nature only plays a role beyond the dams – in the remains of the once expanded alluvial forests. In the 19th century the river had been straightened to create farmland. 1962 the hydropower plant of the Upper Danube AG (ODK), including storage reservoir, was builtThe facilities are operated by the BEW. The BEW is a subsidiary of the Lechwerke (LEW).
The LEW group generates electricity in 36 hydroelectric plants at the Danube, Iller, Lech, Wertach and Günz. Today the rivers of the hydropower plants are ecologically improved according to the Water Framework Directive. At the Iller between Kempten and Memmingen natural bypass channels were built on 5 barrages so fish species such as grayling, common case and Danube salmon can continuously pass the river again.
Now a new concept was developed for the Danube, which was introduced to the council of Elchingen by Ralf Klocke on 14/03/2016. The EU has already been convinced by the plan.They are supporting the project with 650,000 euros. The councilors of Elchingen are also pleased with the goal, that the dam at Oberelchingen will have a more natural riverside in the future. Each pilot site covers 500 meters at Oberelchingen and Offingen. On an exemplary area in Gunzburg, test sites are already implemented. The “child” even has a name: “Eco-Berm”. The highlight: The ecological restoration of the dam doesn’t take place on the side of the alluvial forest, but in the to 250 meters widened river just in front of the power plant. “So we reduce interference in the riparian forest.” says Klocke. In front of the dam a shore landscape with a width of three to ten meters is created. “We have already discussed with the fishermen from Neu-Ulm to Offingen how it could be used by them” said Klocke. Also open areas are possible, so that the river will be accessible for people again.
This is achieved by the sediments that the Danube has deposited on the water side of the dams over the past decades.They will provide the basis, explained the project partner Sebastian Blass from the Aueninstitut Neuburg. In the power plant construction berm means a step in front of the dam. the structures are built on the gravel bed, so a new shore surface, which is separated from the dike, arises – as a new natural habitat for flora and fauna. “Previously we did seal the dam”, so the water can’t flow in the housing complex, added Klocke. The storage area will indeed be reduced, but this is no significant loss for the plant operators. “We only use the steady water flow in the middle of the river to generate electricity.” In times of the energy transition impoundments as they were done in the past are not part of the operational management anymore. The Danube will also deposit sediments at the exterior side of the river, so the eco-berm can further develop. Due to the higher flow speed, the middle of the river bed remains free anyway.
The schedule: The construction works start in the late summer, in spring 2017 they should be finished. After that the monitoring activties of the project partner, the University of Innsbruck, start. They have to examine the ecological impact and the stability of the dam. Then the concept can be applied to other shore areas. At the end a dam will be elevated by about half a meter. But not to continue the impoundment of the Danube and to increase the capacity, “then we would take away capacity of the upstream river”. The reason is the climate change and the increased risk of flood events. “We have to be prepared for it.”
SOUTH West Press author: MICHAEL JANJANIN, 03/16/2016Pilot scheme: Elektrizitätswerke renaturalize shore at ElchingenELCHINGEN: The ODK AG / Bavarian Electricity and the EU invest 1.4 million Euro, to enhance the ecology of the impounded Danube at Elchingen. In addition, the dam will be better protected against floodwater.