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Stornorrfors – generating large amounts of electricity

Stornorrfors
Stornorrfors generates the most electricity of all hydro plants in Sweden. Stornorrfors is the second-largest hydro power plant in Sweden, surpassed only by Harsprånget. It is beautifully situated by the Ume Älv River in the north of Sweden. Stornorrfors Hydro Power Station incorporates four turbines and was first commissioned in 1958. Vattenfall co-owns the Stornorrfors facility together with Umeå Municipality.

Extensive work to increase safety

In 2007, Vattenfall began work on increasing the safety of Norrforsdammen, the dam adjacent to the Stornorrfors facility. The project included the construction of a new fish ladder, the installation of a new power plant adjacent to the fish ladder, a new spillway and increasing the height of the dam crest to the left of the facility. The initiative is a step towards achieving Vattenfall’s ambition of increasing the safety of its hydro power stations to be able to handle the ‘10,000 year flood’ – an event with extremely high water levels, expected to occur once every 10,000 years.

Fish breeding

Vattenfall completed a new fish ladder adjacent to the facility in 2010. It is now one of Europe’s longest fish ladders and it helps salmon swim upstream every year to reach their breeding grounds in the Vindelälven River. (Vindelälven is a tributary to the Ume Älv River, the biggest tributary river in Sweden and one of the country’s four large unregulated mountain rivers).

The ladder is 300 metres long and also incorporates the option of moving smolt, or fish larvae, downstream to reach the Baltic Sea where they can grow and thrive. The option of moving smolt downstream is unique and the first of its kind in Europe.

In Sweden, power companies operating hydro power stations are obliged to breed fish to compensate for the destroyed breeding grounds as a result of river regulation. One of Vattenfall’s largest fish-breeding plants is located in Norrfors, close to the Stornorrfors facility. Every year, Vattenfall releases 80,000 salmon smolt, 20,000 sea trout and 20,000 grayling. In co-operation with the Vindelälven Fish Council and the Swedish University of Agricultural Sciences, Vattenfall also analyses how the passage of fish past Stornorrfors can be improved. Furthermore, the fundamental biological and ecological relationships in the river are continuously analysed.