Dam types

There are many types of dam constructions to meet different needs in Finland, some of which are built across rivers and lake outlets, while others hold waste water or protect land areas from floods.

A water storage dam can be defined as a structure that dams water for such purposes as flood protection, hydropower production or fish farming. Some of them are regulating dams used to adjust the water levels and flow rates of rivers and lakes.

A river basin may incorporate a large complex of dam structures, including several power plant dams, or regulating dams, made of concrete as well as long earth dams and flood embankments.

Kyrkösjärvi reservoir in Seinäjoki, for instance, consists of an earth dam of around ten kilometres in length, a power plant dam and two regulating dams.

As their name indicates, flood embankments are built along a river or a lake to prevent floods from spreading to settlements or other sites.

Waste dams in connection with industrial plants and mines retain substances resulting from industrial production, which may be harmful or hazardous for health or the environment.

The most recent power plant dam in Finland was completed in 2001. However, flood embankments and several waste dams on mining sites have been built since then.