Annual report 2012

Hydropower and the environment


Hydropower and the environment

Successful fish stock management

Hydropower production has regional and local impacts on waterways and fish stocks. In order to fulfill its obligation to sustain the fish stocks of the Kemijoki and Iijoki waterways and the sea area, PVO-Vesivoima Oy stocked around 2.9 million fry in 2012. Together with Kemijoki Oy, 4.9 million fry were stocked in the Kemijoki sea and river area; of these, PVO-Vesivoima Oy’s share was 17 per cent, or 0.8 million fry. On the Iijoki River, transporting of river lampreys past dams and power stations was very successful: the actual number of transported river lampreys – 72,765 – clearly exceeded the obligation of 60,000. On the Kemijoki River, the shared obligation of PVO-Vesivoima and Kemijoki Oy is 100,000 transported specimens. In 2012, double the required number of river lampreys, a total of 204,420, were transported. However, the accumulated annual obligation still shows a deficit equal to the number transported in 2012 due to the poor river lamprey catch of previous years.

New fishways established

Together with the municipalities of the Iijoki river region and other key stakeholders, PVO-Vesivoima Oy is participating in a project focusing on the Iijoki river fishways, co-ordinated by the Centre for Economic Development, Transport and the Environment for Northern Ostrobothnia. The project was launched in summer 2011, and it will cover the period from 2011 to 2013. The target of the project is to create detailed plans for fishways at the power plants in the lower reaches of the Iijoki river and to apply for construction permits for the fishways. Applying for permits requires the establishment of a joint municipal administration body. The Kosto dam fishway included in the project was completed in November 2012. The fishway will have no impact on the control of the waters in the Kostonjärvi lake.

The second Isohaara fishway, built into the timber rafting tunnel of the old Isohaara power plant, was completed in 2012, a year later than planned. The construction project was administered by the Centre for Economic Development, Transport and the Environment for Lapland.

Renovation programme to reduce the risk of oil spills

The new technology adopted within the hydropower renovation programme has resulted in considerable environmental improvements compared to earlier technology. The risk of oil spills has been significantly reduced as lubrication oil has been replaced with water in the hub bearings of new turbines.

Periodic inspections required by the Act on Dam Safety were carried out in 2012 at the Jumisko, Kierikki, Kosto, Irni, Taljajärvi and Maunujärvi dams.