Denmark: Skjern River Restoration

Project Stage:
Completed

Start Date:
1987-08-23

End Date:
2002-08-23

Primary Causes of Degradation

Degradation Description

Between 1962 and 1968, the Skjern River was straightened, deepened and embanked, and dikes and drainage channels were built to lower the groundwater level and enable the conversion to agricultural land. As meandering watercourses were replaced by long, straight channels and dikes, 4000 hectares of wetlands, meadows and heaths were gradually converted into an arable prairie. As floodwater no longer flowed overland, and as fertiliser was liberally applied, the floodplain began to act as a huge ‘source’ of nutrients, and was no longer a ‘sink’ for sediments. This had a disastrous impact on the fjord as it became silted up and polluted. Problems also arose in the drainage area itself. With exposure to oxygen resulting from cultivation and drainage, the peat-rich soil sank–more than 1 metre in a number of places–and drainage became ineffective. Furthermore, water turned bright red due to high concentrations of ochre, a toxin for fish and other oganisms.

Reference Ecosystem Description

At the mouth of the river, where there was once a huge expanse of marshland (4,000 ha) and a variety of wetland habitats, wildlife once abounded. In addition to the thousands of migrating birds who used it as a stopping over point along the Western Palaearctic flyway, there were also stable breeding populations of bittern (Botaurus stellaris), black tern (Chlidonias niger) and corncrake (Crex crex). Other species, such as the otter and Atlantic salmon, were also relatively common.

Project Goals

– To reinstate flow conditions of the Skjern River and remove unnatural barriers
– To improve the aquatic environment of RingkÁ¸bing Fjord and allow the river, fjord and sea to function as a single biological entity
– To enhance conditions for migratory fish
– To recreate a natural wetlands habitat of international importance
– To develop the leisure and tourist potential of the Skjern River Valley

Monitoring

The project does not have a monitoring plan.

Description of Project Activities:
The period 1987-1999 was dominated by public debate, scientific and technical surveys, land acquisitions, land allocations, legislation, planning, environmental information, etc. The actual construction phase was carried out in 1999-2002. During this phase, dikes around the long, straight watercourses created in the 1960s as part of the drainage project were removed, and the old channels were filled with soil. A new, meandering river course was excavated and has increased to 26 km the lower section of the river that was formerly only 19 km of straight channels. The restored river has been laid out with several outflows into the fjord, and in time, this will create a delta of approximately 220 hectares. In addition to the reconstruction of the watercourse, five drainage bridges and two pumping stations have been removed from the project area. Consequently, periodic natural flooding will be allowed once again, and contact between the river and adjacent riparian areas will thus be re-established. In order to protect surrounding fields and towns from the natural floods expected to occur inside the natural area, 1.5 km of new dikes have been built. Some sections of original dike have also been preserved, the most important being Skjern River's North Dike, which now forms the northern boundary of the natural area. The final stage of the project, completed in 2005, was the establishment of facilities for the public and for dissemination of information--i.e. walking trails and observation stations.

Ecological Outcomes Achieved

Eliminate existing threats to the ecosystem:
The overall project assessment is unambiguous: The nature restoration project has been successful. More than 4 km of new, meandering watercourses have been dug in the 2,200-hectare natural area. These new watercourses - parts of Skjern River, Omme River and GundesbÁ¸l River - have been returned as far as possible to their original winding routes. The length of the main course of Skjern River has increased from 19 km to 26 km. The area now consists of an open river valley with meandering watercourses and a mosaic of meadows, shallow lakes and reedbeds. This environment provides perfect conditions for flora and fauna. The groundwater level is no longer being lowered by pumping, so the leaching of ochre sediment in the project area has virtually stopped. At high water, floods inundate the surrounding meadows, depositing nutrients emitted by agriculture and aquaculture facilities. These substances are effectively filtered and prevented from entering RingkÁ¸bing Fjord, where they would have a negative impact on the fjord environment and the fishing industry. The project area now offers ideal conditions for flora and fauna and has already acquired great natural value. In fact, it has already grown into a bird site of national importance. Birds began arriving by the thousands almost as soon as the excavators left the area. Since then, no fewer than 212 different bird species have been registered in the area, and more are being added to the list all the time. The new natural area is an important staging post for many bird species on their way between their winter quarters in Southern Europe and Africa and their breeding grounds in the north and east. These migrant species include: lapwing, golden plover ruff and dunlin. The area offers particularly suitable breeding conditions for grebes, certain dabbling ducks, and birds of the reedbeds and marshes. While some species rely on the site as a breeding ground or stopover point on their migration, many species remain in the area year-round. These perennial species include: mute swan, coot, cormorant, grey heron, greylag goose, many species of duck, and others. In the winter large flocks of greylag geese, pinkfooted geese, barnacle geese and whooper swans can be seen. The area also provides food for many different species of raptor. Marsh harriers breed in the area and can be seen hunting mice and small birds throughout much of the year. Osprey, white-tailed eagle and peregrine can be seen on their migration in the autumn and winter months. Other visitors include: hen harrier, kestrel, merlin and red kite. In the winter, the area is home to a large numbers of raptors that includes the buzzard and rough-legged buzzard. Besides important bird species, the new natural area has also provided a home for otters. The watercourses contain a large number of the fish on which they feed, as well as good places to hide and breed. The otter is threatened in Denmark, but during the 1990s it spread to West Jutland where its success is attributable to the restoration of watercourses, reduced use of pesticides, and increased protection. The restoration project has improved conditions for fish. The variety of watercourses has created better conditions for spawning fish and better conditions for fish fry as well. The removal of barriers has allowed access to other sections of the river system for certain species of fish, particularly the whitefish, which is a small salmon. The river now holds the typical species of rivers and lakes, such as river trout, perch, pike, roach, bream, stickleback, grayling, burbot and eel. There are several species that live in the fjord and spawn in the river, including smelt, whitefish, sea trout and salmon. The increasing number of salmon in the Skjern is a positive sign, as the Danish salmon is the only strain of wild salmon left in Danish rivers. Before this project, the salmon had almost gone extinct owing to the state of the environment. Skjern Meadows have already acquired a fascinating and rich insect life, including three species of great international importance. The green snaketail (Ophiogomphus Cecilia) is a predatory insect that hunts in the air, catching flying insects such as flies, wasps, mayflies, butterflies and other dragonflies. It is protected in Denmark and covered by the EU's Habitat Directive, which means that it may not be caught or killed, and the sites where it is found may not be damaged or destroyed. The mayfly (Baetis calcaratus) is rare all over Europe, and is on the so-called Red List of species for which Denmark has a special responsibility. The same applies to the stone fly (Isoptena serricornis), because most of the world population of this species lives in Denmark. The improved quality of the river water has created good conditions for this species, which seems to be increasing. Two very rare aquatic plants now thrive in the project area, and have been flourishing since the completion of the restoration: Coleman waterdropwort (Oenanthe fluviatilis), which is only found in West Jutland and Ireland, and floating water plantain (Elisma natans), which is threatened by extinction in Europe and only found at a few sites in West Jutland. The uncommon arrowhead (Sagittaria sagittifolia) often covers the surface of the water completely in some sections of the delta.

Factors limiting recovery of the ecosystem:
The project had as its original goal the establishment of 1600 hectares of grassland. However, only about 1200 hectares of grassland have been successfully established due to an increase in the area occupied by lakes and wetlands. Although grassland will not be as extensive as originally hoped, the increase in wetland area will be of great benefit to such important species as the spotted crake, avocet and bittern.

Socio-Economic & Community Outcomes Achieved

Economic vitality and local livelihoods:
The last phase of the project was the establishment of recreation facilities in the project area. The site has attracted a growing number of visitors, and by the end of the project, it was estimated that 350,000 to 400,000 people had visited the site. The 17.4 km of trails and 3 observation towers make the site accessible and allow for the enjoyment of the area's birdlife without much disturbance or negative impact.

Key Lessons Learned

The Skjern River system is the largest in Denmark and drains a substantial portion of the country’s land area before flowing into RingkÁ¸bing Fjord. This entire water system, and the surrounding area, should be seen as a single biological entity: the Skjern River system, RingkÁ¸bing Fjord and the North Sea. Fish provide an illustrative example of the interdependency of these seemingly distinct systems. Many species live in the sea and the fjord but spawn in the river and its upper tributaries. In order to survive and reproduce, these fish need clean water and easy access to suitable spawning grounds. Thus, the river is integral to the health and vitality of both the fjord and the sea. Therefore, the restoration project, despite having only affected a small part of the total water system, has had a significant impact on the flora and fauna further up the river system and in RingkÁ¸bing Fjord.

Long-Term Management

A proposal for establishment of the Skjern River National Park has been sent to the Danish Minister of the Environment. This was the result of a joint initiative involving the project’s beneficiaries, municipalities and local/regional NGOs. National park status would facilitate the protection and effective management of the site and ensure its vitality into the future.

For the long−term sustainability of the project’s results, especially with regard to birdlife, it is essential that the wetland and meadow area are grazed. This includes Kalvholm Island, which is situated between the northern and southern branches in the outlet area of the river. A special barge was constructed for the transport of cattle to this island.

Sources and Amounts of Funding

283 million DKK The restoration project has cost the state DKK 283 million (EURO 35 million), DKK 100 million of which was used to purchase land for inclusion in the project. The European Union, through its LIFE programme, has contributed DKK 25 million.

Other Resources

Project Website
http://www.skovognatur.dk/Lokalt/Jyllandsyd/Oxboel/Skjern_Enge/Skjern+River+Wetlands.htm

Primary Contact

Organizational Contact