Pioneering Stegenwald hydropower plant opens on Salzach River

Austrian power company Verbund and utility Salzburg AG have announced the official opening of the new Stegenwald power plant on the Salzach River.

The plant marks the seventh to emerge from the partnership, which has aimed to boost the region's climate and power resilience.

The €100 million ($117 million) hydropower plant took only two and a half years to build and can now supply 74GWh annually for approximately 20,000 households

Verbund CEO Michael Strugl hailed the project as a model for future developments.

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Said Strugl in a press release: "The construction and commissioning of the Stegenwald power plant on the Salzach River is a success story and demonstrates how technical expertise and close cooperation between the project partners VERBUND and Salzburg AG lead to excellent results. Despite numerous challenges, such as the once-in-a-century flood in August 2023 and a temporary construction halt last year, construction was completed on schedule and within budget."

Strugl also highlighted the length of time it took to secure the permits for the project, stressing the situation needs to be addressed with a sense of urgency.

"The Stegenwald example also shows that the approval process for the power plant took about five times as long as the actual construction. This must change for the sake of our energy security and climate neutrality. We need faster procedures and simpler frameworks. Laws that are clear enough to be implemented. Only through a reliable framework can we mobilise the necessary funds and implement our projects efficiently. If this doesn't happen faster, it will take longer and be more expensive."

According to Michael Baminger, CEO of Salzburg AG, the utility will be investing more than €1.5 billion ($1.8 billion) over the next few years into transforming and greening the energy system.

Said Baminger: "We aim to almost double our own renewable generation. Together with Verbund, we have taken an important step in this direction by constructing the Stegenwald power plant."

Innovation at Stegenwald

According to Verbund, the Stegenwald power plant incorporates several innovations.

The Kaplan turbines were installed horizontally allowing the machine bays to be used simultaneously for flood relief. The overflow of the turbine house allows approximately 20% more water to be discharged in the event of flooding.

This design reduced build time by a quarter, states Verbund, compared to other run-of-river plants of this size.

Also, the project saw ecological measures implemented throughout the approximately 6km long project area.

New approaches were taken to water flow and flow velocity in the reservoir to optimise riverbed elevation. This created a more suitable habitat for fish, which was important as this stretch of the Salzach River offered little such habitat.

In mid-February 2025, work began on redesigning the old riverbed, creating a new bypass stretching approximately 500 meters and up to 60 meters wide.

Verbund Hydropower managing directors Michael Amerer and Karl Heinz Gruber stated: "Biodiversity, climate protection, and energy security cannot be viewed as either/or.

"Here in Stegenwald, around 500 ecological measures have created new habitats for frogs, dragonflies, birds, and a variety of plants. In the coming months and years, a team of experts will monitor and document the functionality and efficiency of the ecological measures through comprehensive monitoring. This ensures that the Stegenwald power plant becomes known not only for clean energy, but also for its positive impact on nature."