The eco-berm offers an innovative and sustainable approach to elevate and rehabilitate dams, without affecting the adjacent floodplain.
Water side slope of embankments in storage spaces were mostly covered with concrete walls. If dam elevation or restoration is necessary, the walls must be replaced. This process is relatively expensive and does not lead to an improvement of the ecological functions. The standard construction of dam elevation requires also a widening of the embankment slopes on the air side and often a diversion of the interior drainage. That leads to a considerable interference in the riparian forests (mostly FFH areas) and the need of appropriate compensation areas.
Due to this background, the BEW has developed a new approach of dam restoration and dam elevation, which will be implemented and tested in the context of the LIFE-project INADAR, co-funded by the European Commission. Central point of the new approach is the installation of so-called eco-berms at the waterside of embankments in storage areas.
At three small test fields with a length of 30 meters the eco berms have already been tested in the Upper Danube (at the barrage of power plant Gunzburg). These tests were promising and showed a visible improvement of the storage space as a recreational area and an environmental improvement by creating new habitats for animals and plants.
As part of the LIFE-project, which is scheduled for three years, two pilot sites will be implemented. At the location in the storage space of the power plant Offingen/Danube therefore an eco-berm is installed over a distance of 500 meters in order to rehabilitate the dam on the one hand and to achieve ecological improvement on the other hand. At the test field at the power plant Oberelchingen the dam will additionally be elevated by 70 cm.