Main characteristics of the Finnish surface waters
Finland is known as a land of numerous lakes and clean waters. There are about 56 000 lakes with a surface area of over one hectare and about 2 600 lakes larger than one square kilometre.
Because of the relatively cold climate and prevalent pre-Cambrian bedrock, the rate of weathering is slow and, therefore, the concentrations of inorganic substances in Finnish surface waters are low. By contrast, the concentrations of dissolved organic substances, for example, humic acids, can be high locally, since bogs cover about 30% of the area of the country. The waters of Finnish lakes and rivers are mainly soft and often humic. The shallowness of lakes (average depth about 7 metres) and relatively low discharges of rivers, together with the long period of ice cover, make inland waters sensitive to pollution. Generally speaking, the water quality of Finnish inland waters improves from south to north and from west to east, being poorest in coastal areas in the south, southwest and west.
In many places, lakes and rivers form lake chains. Finland's rivers have a combined length of more than 21 000 kilometres, but mostly they are very short individually.
The Finnish coast is heavily embayed and fringed with 73 000 islands and islets. The Baltic Sea is shallow with a mean depth of only 55 metres. The fact that the Baltic Sea forms a mostly closed, shallow and cold brackish basin means that coastal waters are also highly vulnerable to pollution. Harmful substances degrade slowly under the cold conditions and the winter ice cover prevents oxygen being transferred from the air to the surface water.
Water protection in Finland
Finland has achieved good results in water protection by setting quantitative national water protection targets with specific time frames. The United Nations World Water Assessment Programme examined water quality indicator values in 122 countries. Finland was the highest ranked country in this assessment (the World Water Development Report in 2003). According to the water poverty index devised by the World Water Council and the British Centre for Ecology and Hydrology, Finland was also ranked number one in the world, among 147 countries included in the comparison. The criteria of this comparison included resources, access, capacity, use and the environment. However, there is still a lot of work to be done on water protection, for example, reducing eutrophication in lakes and the Baltic Sea.
Since the beginning of the 1970s, three national water protection programmes have been prepared, and the Government has adopted the two most recent ones. In these programmes quantitative targets for the most important pollution sources were defined. The third national water protection programme approved by the Government in 1998 sets targets for the year 2005. The long-term goal is that the state of the Baltic Sea and of inland surface waters is not degraded any further by human activities. The main aim of this programme is to reduce the eutrophication of the waters.
In April 2002, the Finnish Government adopted Finland’s Programme for the Protection of the Baltic Sea. Steps will be taken to combat eutrophication, decrease the risks caused by hazardous substances, reduce the risks of maritime traffic, protect biodiversity, and increase environmental awareness and research.