Each hydropower plant on the Inn comprises:
- the machinery hall with the turbines,
- the weir systems for flood release,
- the dams and dikes for the accompanying flood protection
- and – if inland drainage has been disrupted by the dams – the pumping stations and ditches, which guarantee agricultural use that existed before construction of the barrage.
The VERBUND hydropower plants on the Inn are therefore not only plants for generating electricity but also improve flood protection in the region. VERBUND also focuses on improving the ecological conditions at individual sites and on restoring natural river landscapes. We implement a large number of measures in this regard, such as:
- creating continuity of flow with fish bypasses,
- giving structure to bodies of water,
- connecting tributaries.
In order to guarantee habitats for fish with all their habitat requirements – from spawn to adult specimens – management of the gravel banks is additionally carried out in the near-natural fish bypass or below the weir. Another important component for the long-term conservation of fish fauna is the maintenance of sediment continuity through sediment management, a topic of the EU Water Framework Directive (WFD) for species conservation in man-made rivers.
Together with the Rosenheim and Wasserburg district fishing association, VERBUND undertook land restoration measures around the Rosenheim and Wasserburg reservoirs. These activities make a big contribution to conserving and improving the varied and biodiverse “Inn ecosystem”. The Wasserburg power plant is equipped with a fish bypass. Gravel spawning grounds in the tailwater have been ecologically enhanced in recent years, some old water systems redesigned and reactivated.
The shallow water zones in the dammed area are under conservation and were declared “Vogelfreistätte Innstausee bei Attel und Freiham” (Bird Sanctuaries Inn Reservoir at Attel and Freiham) by the Bavarian state government in 1982. The protected area begins 600 metres to the south of the dam stage and extends as far as the bridge at Griesstätt. The protected area encompasses 562 hectares of river and sedimentation areas, floodplain forest and steep forested banks.