Beznau hydraulic power plant start of construction

28.04.2025 – Extensive construction work will be carried out around the Beznau hydraulic power plant (HKB) from the beginning of May until around the end of the year. As part of the new licensing process, Axpo is implementing several ecological replacement and compensation measures.

In summer 2023, Axpo received a new licence from the Aargau Cantonal Council to operate the HKB. This came into force retroactively on 29 August 2022 and will remain valid until 2052.

As part of the licence renewal, six ecological replacement and compensation measures are planned on the left and right banks of the residual water section and the reservoir area. The focus is on enhancing aquatic habitats. In addition, the ecological situation of the wildlife corridor of national importance connecting the Jura and eastern Switzerland above the weir can be improved.

Around eight months of construction

Axpo will begin implementing the planned replacement and compensation measures at the beginning of May. This work will continue until around the end of the year. The measures include:

• Left bank of the residual water section: Eight groynes (structures built across the Aare) made of stone blocks and dead wood will ensure sedimentation, diversity of currents and important refuges for fish and other aquatic life.
• Right bank of the residual water section: A gravel bank will be loosened over an area of up to 10,000 m² to restore it as a spawning ground for gravel-spawning fish such as nase and grayling. Additional structural elements will create shelters and promote the development of young fish and the quality of the habitat.
• Shallow lake at Grossmatt/Au: The removal of a bank dam will create a shallow lake that will provide ideal breeding grounds for young fish and refuge areas during floods. The resulting swamp forest (permanently wet, marshy forest) and new structures will also promote plant-spawning fish species and improve the connectivity of terrestrial and aquatic habitats.
• Wildlife sanctuary near Grossmatt/Au: A protected area with native plants and small structures provides a place of refuge for wild animals that use the supraregional wildlife corridor. Nutrient-poor meadows, wetland biotopes and refuges promote rare species such as small mammals, reptiles and insects.
• Kumetmatt/Stalde side watercourse: A 400-metre-long side watercourse with gravel islands, bays and structural elements is being created to promote new habitats for fish and the development of a floodplain forest through natural succession.
• Amphibian waters Kumetmatt/Stalde: Several ponds that dry out periodically will be created to support amphibians such as typical floodplain dwellers and reduce predators. Structures such as brushwood piles provide additional habitats.

These measures create valuable habitats for numerous animal and plant species, improve the ecological conditions along the Aare and strengthen the connectivity of aquatic and terrestrial biotopes.