A new Dam Safety Act (494/2009) came into force on 1st October 2009 and a Government Decree on Dam Safety (319/2010) on 5th May 2010. This Dam Safety Guide replaces the Dam Safety Code of Practice (Publication of the Ministry of Agriculture and Forestry 7/1997), removed from circulation on 1st October 2009. The Dam Safety Guide is not binding on the dam owner; the purpose is to complement and elucidate the relevant law and and decree through examples and descriptions.

The Guide takes up questions concerning dam design, for instance hydrological dimensioning and technical safety requirements, dam construction and use, the dam break hazard analysis and the dam owner’s emergency action plan, maintenance, use, monitoring as well as the annual and periodic inspections.

Dams are classified according to the hazard they pose into class 1, 2 or 3 dams. The classification is not needed, if, according to the dam safety authority, the dam poses no danger. The owner of a classified dam must prepare a monitoring programme, to be approved by decision of the dam safety authority. To establish the hazard caused by a dam, the owner of a class 1 dam must prepare an analysis of the dam hazard to humans and property as well as to the environment. The dam safety authority may also require a dam break hazard analysis for a dam other than class 1 dam if deemed necessary for classification. The owner of a class 1 dam must prepare a plan of measures in case of emergency or operational failure. The plan shall present the dam owner’s state of preparedness to act on their own initiative in the situations described above. In each case, the rescue authorities make a separate assessment for the need to prepare a plan as set out in the Rescue Act. The dam owner must provide the information specified in the Dam Safety Decree to be entered into the dam safety information system. The dam safety authority and the owner of the dam must keep up-to-date printouts in their own dam safety files from the information system for each dam as well as other important documents connected with dam safety to ensure that these are readily available in case of disturbance.