VERBUND began restoring the Aufhausener Lacke near the Egglfing-Obernberg Inn power plant in autumn 2024 as part of the LIFE Riverscape Lower Inn nature conservation project. The work was completed at the end of March 2025 and the new still water body was flooded.
Work on the new Aufhausener Lacke is making progress:
The ‘new’ Aufhausener Lacke is being developed as a near-natural floodplain water body. Once completed, the still water body will remain in existence for decades and serve as a valuable habitat for fish and water birds as well as amphibians and insects in the Inn floodplains. It will be equipped with shallow water zones and deep areas.
By connecting the deep zone to the Inn, fish will also be able to use the Aufhausener Lacke as a habitat again. And the shallow water areas will once again provide a perfect environment for fish larvae and juvenile fish as well as for waterfowl.
The sightings took place between May and July 2024. The ecologists commissioned by VERBUND were even able to observe a pair of red-necked grebes mating. Afterwards, only the male was present in front of the reeds, suggesting that the female was hiding near the nest, as is usual for this species.
‘The pleasing sighting of the red-necked grebe shows how important intact floodplain waters are for water birds. As part of the ‘Riverscape Lower Inn’ nature conservation project, VERBUND is ensuring that there will be even more and better breeding habitats for the red-necked grebe and other birds along the Inn in the future,’ says VERBUND project manager Roland Schmalfuß.
Preparatory work starts in October
A few weeks after the opening of the Braunau Simbach fish migration aid, VERBUND is starting preparatory work for the next bypass water around 30 kilometres downstream at the Egglfing-Obernberg Inn power plant. This nature conservation project is also part of the EU LIFE project ‘Riverscape Lower Inn’, which further promotes the near-natural development of the river landscape on the Lower Inn.
In 2025, construction work will begin on the largest near-natural bypass on the Inn to date with a length of 5.8 kilometres. The ground-breaking ceremony for this pioneering nature conservation project is expected to take place in spring next year. Before this can happen, the entire construction site must be cleared. The necessary clearing work will begin at the end of October and is scheduled to last until the end of February. The remaining preparatory measures will be completed by the end of May 2025 at the latest.
As a first measure, hollow trees that serve as valuable habitats will be carefully removed and reintegrated into nature at other suitable locations. All of the work will be carried out in close coordination and under the supervision of an ecological construction supervisor and has been agreed with the authorities.
After just under a year of construction, the new fish migration aid enables all species of fish in the River Inn to swim past the Braunau-Simbach power plant or stay there for a while. For the first time since the construction of the power plant, the new bypass water allows them to freely reach the tributaries or floodplain waters again. The bypass also provides new habitats: wood, stones and above all gravel form typical river structures in the water and on the banks. Habitats are created for fish, birds, insects and amphibians. In addition to the fish migration aid, a natural riverbank was created on the Inn downstream of the power station. Fish migration and habitat development are documented scientifically on an ongoing basis through extensive monitoring.
The fish migration aid at the Braunau-Simbach Inn power plant was completed in July 2024. The video shows the progression from its construction and commissioning to the completion of the fish bypass.
After a construction period of around one year, the new fish migration aid at the Braunau-Simbach Inn power plant has been completed and was filled with water for the first time on July 10, 2024.
Trial operation begins with the first water dotation. During this time, all relevant discharge scenarios are tested. During the initial flooding, the new water bed is slowly filled with a small amount of water and, once the bed is saturated, a continuous discharge situation begins to develop. In addition to the installed sealing elements, the sediment load of the Inn causes a slow process of self-sealing in the new watercourse.
During trial operation, the flow conditions at different discharge volumes are checked and, if necessary, the watercourse is reworked together with the construction supervisor. The bypass has a variety of structures such as gravel zones, pieces of wood and stones as habitat features. The embankments of the stream bed, which will be increasingly integrated into the existing landscape, serve as a habitat for birds and insects.
Once the trial operation has been completed successfully, the flow rate of the new, three-kilometre-long fish migration aid will be determined according to the seasons with discharges of between 2,000 and 6,000 l/s.
The official opening and commissioning is planned as part of an open day on September 21, 2024. By then the remaining work on the accompanying paths and the installation of railings will be completed.
On May 21, 2024, leading decision-makers from Bavaria and Upper Austria were informed about the construction progress of the new bypass watercourse at the VERBUND Braunau-Simbach power plant as part of the Natura 2000 Day.
from left to right - Christoph Stein, Bavarian State Ministry for the Environment and Consumer Protection - Johann Springer, Mayor of Kirchdorf am Inn - District Administrator Raimund Kneidinger (Passau district) - Rainer Haselbeck, District President of Lower Bavaria - Deputy District Administrator of Rottall-Inn Edeltraud Plattner - Günter Winterstätter, Braunau am Inn town councillor - Gerold Bauer, 3rd Mayor of Ering am Inn - Herfried Harreiter, VERBUND Hydropower
Floodplain adventure afternoon with the Natura 2000 rally
On May 21, 2024, a floodplain adventure afternoon for families will take place at the Waldsee in Kirchdorf am Inn (Bavaria) around the Braunau-Simbach Inn power plant. Young and old can discover the ecological measures implemented in the river landscape as part of the EU LIFE Riverscape Lower Inn project and experience them with the "Natura 2000 Rally".
Throughout the area there are informative and entertaining experience stations:
Learn more about the "LIFE Riverscape Lower Inn" project with VERBUND and explore the new bypass water at the Braunau-Simbach power plant with guided tours.
Naturium on the Inn
Children's adventure station of the Bavarian Academy for Nature Conservation and Landscape Management
Life in the Inn at the bypass with fish you can touch
Meadow habitat at and on the Inn dams
Observing birds at the forest lake with spotting scopes
VERBUND, the Bavarian Academy for Nature Conservation and Landscape Management (ANL) and the Naturium am Inn are the organizers of the action day to mark European Natura 2000 Day.
The "ice channel" is a connection between the main branch of the Inn and an oxbow lake, also known as the "Heitzinger Bucht". Through this connection, around 8,000 m³ of fine sediment enter the old Inn water system every year, causing turbidity and sedimentation. The habitats now benefit from the closure of the ice channel. Greater depths of visibility and higher water temperatures in the oxbow lakes will encourage the growth of aquatic plants and improve the habitat for bird, amphibian, fish and insect species.
Start of construction on the near-natural bypass river of the Braunau-Simbach power plant: the dynamic design of the bypass river offers space for protecting species diversity in and around the water.
VERBUND has implemented an exemplary project for river continuity and habitats at the Ering-Frauenstein power plant. The "Passability and Habitat" project, implemented by VERBUND at the Ering-Frauenstein power plant, was exemplary and largely responsible for the creation of LIFE Riverscape Lower Inn.
Initial work for ecological measures for connecting waterways, wetland dynamics and habitats on land and in the water over a length of approx. 3.0 km
The Inn bank in the area of the Mattig estuary is now being dismantled as a contribution to the INTERREG project “INNsieme”.
