IW16 Regulation development

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Development

Watercourse regulation covers 38% of water bodies in Finland (1.3 million hectares, IW5 indicator). Of this total area, 79% has been covered by various development projects. The aim of these projects has usually been to improve flood protection, but nowadays (in the 21st century) most projects also include biodiversity acions. These actions have mostly been concentrating on coastal vegetation and fishery.

The area covered by regulation development projects has increased since the 1990s. At the beginning of the period under review, development projects focused on the largest watercourses, which also led to a rapid increase in the area covered. In recent years, the new lakes covered by development projects have been smaller, and although several projects are still ongoing, the area covered by them has not increased so much. The development projects completed by 2018 covered 73% of the area of the regulated water bodies and the ongoing projects cover 6%.

impact on biodiversity

Regulation of waters has primarily been aimed at improving the conditions for energy production and flood control. Particularly in older regulation projects, the impact on biodiversity and the recreational use of areas has been neglected. A sharp drop in water levels during winter exposes the shoreline to freezing, which is detrimental to its plants and other organisms. Shallow-spawning fish, such as pike and whitefish, can also suffer from falling water levels during winter. In the summer, the typical rise in water levels in regulated lakes may increase beach erosion, cause changes in coastal vegetation and impair waterfowl nesting.

Much research and development work has been done to reduce the negative effects of regulation. Regulation development projects have usually focused on one or a few lakes at a time and have often been carried out in collaboration between the holder of the permit, various authorities, and local residents and stakeholders. Based on the results obtained, proposals have been made to improve the conditions for energy production, flood protection, biodiversity or recreational use.

Addressing different, sometimes conflicting, needs at the same time can be challenging. However, at best, solutions that benefit all parties and treat different needs equally can be found. For example, changes to enhance recreational use may be also beneficial to biodiversity. Such changes may include, for example, reducing summer water level variation or limiting winter water level decline. The negative effects of regulation can also be reduced by various remediation measures. Fish stocking and shore vegetation harvesting are examples.