The aim of the protection of waters is to ensure at least a ‘good’ status for surface waters and groundwater. At the same time, their status must not be allowed to deteriorate. In Finland, the protection of waters is planned by river basin districts and marine strategy implementation areas. A river basin district consists of one or more river basins. Within these river basin districts, management plans and programmes of measures are compiled with the purpose of achieving a ‘good’ status for the waters.
In Kajaani, the challenges of water protection relate to the management of diffuse pollution. The regulation of water level has changed Lake Oulujärvi’s character and resulted in overgrown grass and paludification of shore zones. In recent years, mining activities have diminished the status of the waters flowing into the Vuoksi waterways in the south-eastern part of Kajaani. Many small lakes have also become eutrophic as a result of local activities. Long-term monitoring has revealed cyanobacteria in Lake Mainuanjärvi, Lake Salmijärvi, Lake Saarijärvi and in some of the Paltaniemi ponds.