SAK Power Plant Montlingen: Ecological Renovation Completed

The Montlingen power plant has been extensively renovated to sustainably improve fish passage and protection along the Rheintaler Binnenkanal. Work in Montlingen began in October 2023 and required a shutdown of the power plant until November 2024. Recently, the last finishing touches were completed. After the upstream power plants Lienz and Blatten were already renovated in 2022 and 2023, the completion of work in Montlingen now guarantees fish passage in both directions along the entire Rheintaler Binnenkanal.

Free migration is vital for most fish species. The revised Water Protection Act of 2011 mandates the removal of obstacles that significantly restrict the movement of fish. In 2016, the Canton of St. Gallen assessed the three hydroelectric plants on the Rheintaler Binnenkanal as requiring renovation.

Measures for fish passage and protection:

As part of the ecological renovation, a new fish ladder to the latest technical standards and a fish bypass gate were constructed. These elements allow fish to safely bypass the power plant structures. In addition, a new horizontal screen with a bar spacing of just 15 millimetres ensures that fish find their way into the designated downstream channel and do not enter the turbines. 'The renovation proceeded according to plan and represents an important step towards the environmentally sustainable use of hydropower,' explains Martin Hersche, Project Manager SAK.

Investment in the future:

The total cost of the ecological renovation amounts to around 3.8 million Swiss francs. The owners of the power plants will be compensated for the consequential costs of the necessary renovation measures by the federal government through the network surcharge fund. While the power plant was shut down, the turbine was also overhauled at the expense of the power plant operator to ensure long-term operational safety.

Coordinated effect monitoring launched:

Following the recommissioning of the Montlingen power plant in November 2024, coordinated effect monitoring began across all three power plants on the Rheintaler Binnenkanal. Fish are marked with passive transmitters to track their migration behaviour. Initial evaluations show that the fish are using the new ascent and descent facilities. 'The new facilities are a great benefit for the very diverse fish population in the Rheintaler Binnenkanal. Initial results show that the passage works and the fish actively use the migration aids,' emphasises Peter Rey, fish biologist Hydra AG.

The effect monitoring is conducted by a specialised office in close consultation with the cantonal offices for Water and Energy (AWE) and Nature, Hunting and Fishing (ANJF). Over the past 12 months, over 1,300 fish from 17 species have been tagged. The intention is to continue the effect monitoring in 2026 to test over at least two full reproduction periods.

Media contacts:
SAK (St. Gallisch-Appenzellische Kraftwerke AG)
Silvia Brönnimann, Media Office
T +41 71 229 52 09
medien@sak.ch

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