Use of Water resources

Hydraulic Engineering

Subjects in teaching

Using water resources

Although Finland is blessed with plentiful reserves of fresh water, these valuable resources must still be managed and used with care.

Surface water and groundwater reserves must all be managed to ensure they can be exploited safely and economically, while preserving their natural and recreational values. Settlements, agriculture and industry are all attracted to waterside locations, and the consequent multiple use of water resources can put them at risk. Wastewater may pollute watercourses and lead to eutrophication, for instance, while hazardous substances and the extraction of sand or gravel can endanger groundwater reserves. Water may conversely itself represent a threat to human activities, however, since homes, farms and other waterside land uses can all be vulnerable to flooding.

Water services

Water services include the supply and distribution of water, and the collection and treatment of waste water. Water is extracted from surface or groundwater reserves, and then purified and distributed to consumers in the public water supply. After it is used, water is collected in sewerage systems, and then properly treated at waste water treatment plants before being released back into water courses.

Water supply and sewerage policies are designed to guarantee the availability of good quality drinking water, and to ensure that waste water is efficiently collected and suitably treated to acceptable standards.

Hydraulic engineering works include the construction of dams, embankments, canals and reservoirs, and the dredging or clearance of channels, shorelines and waterways. Older waterways and hydraulic engineering structures also need regular maintenance to ensure they can still function safely

Hydraulic Engineering

Hydraulic engineering projects are designed to facilitate the useand protection of water bodies, to support nature conservation, and to prevent floods. Well-planned multi-purpose hydraulic engineering projects can simultaneously benefit flood prevention and drainage schemes, biodiversity, fisheries, and the livelihoods of local people. Environmental conditions of Finland’s lakes and rivershave been affected by hydraulic engineering that have raised or loweredtheir water levels or reshaped the channels and basins.

Environmental hydraulic engineering methods are applied during planning and implementation of projects to ensure that natural conditions and landscape values are maintained or restored, while also considering the needs of people who use waterways

Hydropower

In Finland 20% of total energy is produced by hydro power.

Regulating inland waters

The water levels and flows in many of Finland's inland waters are regulated with the help of dams, weirs or other structures connected to hydropower plants. A total of 220 water level regulation projects have been carried out in Finland, affecting around 300 lakes, which together account for about a third of the total area of lakes across the country.

Most of this water level regulation work was done between the 1950s and the 1970s in order to reduce flooding, to produce hydropower, to facilitate water transportation, and to improve the water supply. More recently, attitudes towards inland waters have changed as issues like nature conservation and recreational values have become more important.

Water regulation projects aim to adjust water levels and flows to improve their suitability for water users, and to meet various goals related to the state of the environment in general. Meeting these often conflicting requirements can be a difficult task.

Water regulation projects are normally carried out by either energy companies or the regional environment centres. Where projects have considerable impacts over wide areas, the relevant water regulation permit may remain in the possession of the State.

(hydropower, flood control reservoirs)

Floods in Finland

One of the most frequent environmental hazards in Finland is flooding. However, floods are generally less common in Finland than elsewhere in Europe, because rainstorms are usually not as severe in Finland, differences in elevation are not as great as in some countries, and the country's many lakes and marshes play an important role in storing excess water. But various types and magnitudes of floods do occur in the country. Typically, floods are caused by snowmelt, heavy rainfall, characteristic ice jams seen in northern climates, wave extremes and, very seldom, dam failures. The extent and impacts of floods depend greatly on local landforms and land use practices, as well as on the prevailing water levels and flows.

Floods always cause some amount of damage; between 1974 and 1998 the annual damage from flooding in Finland was over one million euros. In 1988, a major spring flood alone caused 4-5 million euros in damage. In 1899, an exceptional flood, with a recurrence interval estimated to be at least 250 years, caused nearly 30 million euros in damage, as the flood waters covered over 1400 km2. In a project called the extreme flood project, the regional environment centres estimated flood damage for almost 400 risk areas. According to these estimates, the damage costs from extreme floods (occurring simultaneously) in the whole country would be between 500 and 600 million euros. If the damage is divided according to various human activities, 52% of the damage will be caused to buildings, 20% to industry and 17% to agriculture. In comparison, in 1899, the damage to buildings was 2%, industry, 35%, and agriculture, 56%.

The purpose of flood protection is to reduce damage to life and property. Almost annually, Finnish authorities try to protect against flood damage by preventing ice jams, monitoring the snowmelt and warning against occasional flooding caused by intensive rainfalls. Thus, operational flood control plans have been prepared for all major flood-prone water systems. To enhance flood protection and prevention several extreme flood research projects have also been implemented. A report on extreme floods, which was completed in 2000, included recommendations for flood protection and prevention.

River restoration

Rivers, streams and rapids have been restored in Finland since the 1970s. At first, such restoration work was mainly designed to benefit fish stocks, but improving the scenery and providing opportunities for recreational activities have also become important factors. 

Most restoration schemes have aimed to restore natural conditions in rivers that were long harnessed for log-floating. Such work has already been done along almost all of the most important rivers and rapids, but there is still plenty of work to be done along other watercourses. Important goals today include the removal of any barriers that stop fish and other creatures moving upstream, and the restoration of natural conditions in streams affected by the drainage works carried out widely in Finland to boost the productivity of farmland and forests.

Salmon rivers Fish pass

Log floating, log floating facilities (dams, flumes, dreding etc.)

Waterways are being restored by removing structures built for the purpose of log floating.

Waterway transport

Navigation channels (inland water, sea area), canals, ports, harbours

Recreational use; swimming, fishing, boating, summer cottage

Damsafety - earthdams