Watercourse regulation means altering of water levels and discharges through water structures in order to meet the targets set to water resources management. There are approximately 240 regulation projects in Finland, which affect more than 300 lakes or reservoirs. This corresponds to approximately third of the lake area in Finland.
A regulation project may have several objectives such as flood risk management, hydropower production, water supply, navigation, recreation, water protection, fish farming, water protection or drainage. Each regulation project has a permit subject to Water Act, which defines the water level and discharge limits that must be taken into account. Permit holders are e.g. hydropower or other companies, municipalities and ELY Centres (Centre for Economic Development, Transport and the Environment).
The development projects for watercourse regulation
Majority of the regulation projects have been planned and started between the 1950s and 1970s. Since then the expectations and values have changed. There has been an intensive development work regarding mitigation of the harmful impacts of the water course regulation projects in Finland. Approximately 100 development projects have been undertaken since 1995. Majority of the projects have been carried out in the co-operation of ELY Centres, various authorities, local stakeholders and hydro power companies. The projects have resulted in the recommendations mostly related to the regulation policy and restoration measures. They have improved conditions for recreational use and alleviated harmful impacts of the water course regulation on aquatic ecosystem. Also flood and drought risk management has improved. Ongoing projects investigate whether climate change adaptation requires a revision of the regulation permits.