After a year under construction, Carinthia’s highest fish bypass was ceremoniously commissioned today at the Drava power plant in Edling. For almost sixty years, the Edling power plant formed a barrier in the river to fish and other aquatic organisms. With the new fish bypass, it is now possible to swim around the power plant.
Fish that swim upstream to spawn, for example, can reach the 22.2 metre-higher Völkermarkt reservoir via the 650 metre-long fish bypass from the Drava. “The creation and networking of habitats makes a vital contribution to the preservation and improvement of biodiversity in our waters. We have built more than 1,000 fish ladders since 2009. The new fish bypass in Edling was supported with 450,000 euros from the Federal Ministry for Sustainability and Tourism,” emphasised Federal Minister Elisabeth Köstinger at the opening ceremony.
“Today’s commissioning of the Edling fish bypass not only represents a water ecological upgrading but also reconnects a habitat that was separated decades ago,” says Achim Kaspar, member of the VERBUND AG Executive Board responsible for electricity generation: “We are proud of the diverse value of hydropower and prove every day, especially here on the Drava, that we meet the highest standards for clean and ecologically sustainable electricity generation.”
Ten power plants on the Drava supply more than half of the electricity required throughout Carinthia
“Hydropower is the most important source of energy in Carinthia. Our ten hydropower plants on the Drava form the backbone of electricity generation and supply more than half of the total annual electricity requirement in Carinthia,” says Michael Amerer, Managing Director of VERBUND Hydro Power GmbH, which will invest around 25 million euros in ecological projects in Carinthia alone until 2027 to implement the EU Water Framework Directive.
650 metre-long fish diversion with two tunnels and 24 resting pools
The Edling power plant was built between 1958 and 1962 at the beginning of the Drava gorge in the Jauntal valley, which is why the planning and implementation of the fish bypass presented the VERBUND project team with some tricky challenges: “In order to reduce the enormous height difference of 22.2 metres, 148 individual standard pools, 24 resting pools and a distribution structure with eleven exit openings had to be constructed between the entrance and exit structures. A 15 centimetre difference in water level is overcome per basin,” says VERBUND project manager Sabine Käfer. In addition, the fish bypass had to cross under the main road on top of the dam and the access road to the power plant with two tunnel sections.
Upstream or downstream: fish camera documents every single fish
The construction enables a constant water level in the fish bypass, for which about 450 litres of water flow from the Völkermarkt reservoir into the distribution structure every second. As with the downstream power plant in Schwabeck, the new fish bypass in Edling will also be equipped with a fish camera, which will scientifically document how it is working as part of an extensive monitoring programme.
The total costs for the Edling fish bypass, including the monitoring programme, amount to around three million euros. The Province of Carinthia, the Federal Ministry for Sustainability and Tourism and the European Union are participating in the investment in implementation of the EU Water Framework Directive. With the opening of the Edling fish bypass, seven of the ten Drava power plants are now barrier-free for fish. The remaining three power plants will also be equipped with modern fish bypasses over the next few years.