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Skjern - Restoration of habitats and wildlife of the Skjern River (LIFE00 NAT/DK/007116)

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Key features of the case study

The restoration of the Skjern river (e.g. re-meandering and reconnection of wetlands) is one of the largest and best-documented restoration projects in Europe. Moreover, monitoring has been carried out for a comparatively long time.

Site description

An expansive marshland used to surround the mouth of the river Skjern harboring a mixture of wetland habitats: meadows, reed-swamps, meandering watercourses, fens and shallow lakes. But in the 1960s, a relentless campaign of land reclamation and river channelisation was carried out aiming to turn wet meadows into arable land. Meandering watercourses were then straightened out and dikes were constructed to prevent flooding. Pumping stations and drainage systems were also installed to lower the groundwater level to suit agricultural production. The reclamation had obviously a large negative effect on the wild flora & fauna by damaging the floodplains habitats and affecting the water quality (especially through nutrients inputs), thus resulting to species disappearance (e.g., the Atlantic salmon & the Bittern) but also to agricultural revenues decrease since the land was not up to sustaining such intensive activities (soil collapse, water pollution, etc.). Fisheries were also concerned by the water quality degradation which led to fish resources decrease.

Global objectives

In 1987, the Danish Parliament launched a strategy to restore the Skjern river habitats to their former natural state aiming to improve the living conditions for priority bird species but also for other species such as the wild Atlantic salmon. The objectives were to restore the nutrient retention capacity of the river and its valley, to restore the valuable wetlands and to promote fishery and to increase the recreational and tourist values of the project area.

Specific goals

To achieve those objectives, the Skjern River Act foresaw to:

• Restore 2 200 ha of the river valley
• Improve biological diversity over 1,600 ha by re-introducing grazing
• Rectify poor physical conditions and re-establish its natural self-purification capacity by remeandering the river over a stretch of 20kms
• Introduce appropriate management and land use in the Skjern valley

From 1987, the restoration project had taken twelve years before undertaking any measures since debate, information work, scientific and technical surveys, land acquisitions, land allocations, legislation, planning, environmental information etc were carried out.

Measures selection

A large broad of measures were implemented along the Skjern River through different “sub-projects”. The restoration work of the areas of conservation value for the NATURA 2000 network was undertaken under the LIFE Nature project - Restoration of habitats and wildlife of the Skjern River (LIFE00 NAT/DK/007116) – while the preparation of the new land use plan for the area was funded through a previous LIFE Environment project. Below the whole restoration work is introduced carried from 1999 to 2003:

• The lower 19 km of the channeled river were turned into a 26 km meandering course. Dikes were removed and more than 40km of new meandering watercourses were dug in the 2.200 hectare natural area. The main target was then to wide the water courses since the natural process of a straight river course to change to a winding course would take a too long period of time. Furthermore, the old canalized river stretches were filled up and the pumping stations were removed or disconnected. The meandering plan foresaw to follow as much as possible old meanders as mapped in the 19th century.

• Re-establishment of the contact between the river and riparian areas by permitting periodical floods on land within the project area.

• Transfer of 1,550 ha of arable land to extensive grazing. Only ¾ of the grassland establishments planned was accomplished by the end of the project. The measures implemented actually led to an increase of wetland and shallow lake areas instead of grasslands.

• The river has been laid out with several outflows to the Fjord, which, in time, will create a delta of app. 220 ha.

• Creation of a lake of approximately 160 ha to store water and reduce water nutrients contents.

In order to undertake those restoration works, land had to be bought along the Skjern River. At some places, managers were actually faced to a local opposition; some landowners wanted to keep their land in the valley. Discussions finally led to agreements but the government had to raise the compensation rates for the loss of land and/or production.

Restored meandering water course of the Skern river about 11 years after restoration (Niels Bering Ovesen)

Success criteria

No information found.

Ecological response

Following the restoration work, some ecological improvements were observed along the Skjern River. The restoration of the physical conditions of the river led to a more diverse range of habitats for the river fauna and vegetation, both within the river itself and at the riverbanks. Results and observations until 2003 are introduced below (further monitoring are currently carried but the results are not available yet).

Breeding birds evolution between 2000 and 2003 (Johannes Bach Rasmussen, 2005)

• Important changes in the plant species took place between 2000 and 2003 in the river valley. Domestic, cultivated grasses and typical weeds in cultivated fields were replaced by species typical for natural wetlands, or even water plants.

• The number of salmon returning from the sea to Skjern River to spawn has increased over the last 20 years, from about 100 to 1000 salmon annually. The increased number of spawning salmon was primarily caused by stocking of juvenile salmon but highlights the re-establishment of river continuity and water quality.

• In 1999-2000, otter faeces and footprints were found at 12 out of 19 sites visited. In 2003-2004, the corresponding findings were made at 18 out of 20 sites. It is concluded that there is a marked increase in the occurrence of otter in the entire project area and a permanent population

• The restoration improved both the breeding possibilities and the general survival possibilities of the amphibians common toad, natter jack toad, common frog and moor frog. The improvements were due to the creation of the many shallow ponds and flooded areas surrounded by non-cultivated land.

• The number of species of breeding water birds increased from 7-9 species in 2000 to 31 species in 2003 as introduced in the figure.

• The restoration has turned the project area into an extremely important feeding and roosting site for migratory birds especially dabbling ducks during their autumn migration. More than 105 new species of birds have been registered.

Nevertheless, natural processes take a long period of time before being restored; hence, the 2003 monitoring results don’t reflect the future ecological conditions and further improvements are expected in the near future since the ecosystem haven’t reached yet its equilibrium. Therefore some ecosystems components hadn’t showed real improvements in 2003 but are actually expected to in the near future such as:

• The vegetation coverage was reduced after the restoration, because the plant communities had not yet colonized the shallow river bank zones. Nevertheless, new species were observed in 2003 such as: Branched bur-reed (Sparganium emersum), common waterweed (Elodea canadensis) but also water-plantain which is very rare.

• The Danish Stream Fauna Index values were 7 both before the restoration (2000) and after the restoration (2003) which means that the invertebrates had rapidly colonized the new river reaches.

• Sea lampreys were found at 75% of the investigated locations both before and after the restoration even though a weir was removed.

Besides some ecological improvement, the restoration also led to unwanted impacts hampering others species. Therefore, management plans should be adjusted continuously to consider such conflicting interests. Some examples from the restored area are given below:

• The creation of Hestholm Lake has increased the number of dabbling ducks, grebe and pike, but led to an increase of the salmon smolt mortality due to an increase of predation from herons and cormorants.

• Grazing by cattle or sheep is a precondition for the formation of typical meadow vegetation and birds attached to this habitat, but at the same time it excludes high vegetation and thereby the animals attached to this habitat.

• Grazing near the shores of lakes, ponds and streams prevents the establishment of natural reed belt vegetation and the grazing increases the nutrient loading to the water bodies, but some birds attached to meadows benefit from the naked mudflats created by the grazing animals.

Hydromorphological response

The water levels of surface water and ground water increased within the project area, but no changes have occurred outside of the area. The restoration also led to less regular cross section profiles in the river with larger depth variations and a smaller slope of the riverbanks. The river width and the water depths have generally decreased and the water velocity increased. As a consequence, mud deposits in the river have been reduced and the dominating bottom substrate is sand, but also the occurrence of gravel and stones has increased.

Water quality response

The nutrient load was reduced with more than 200 tones of nitrogen per hectare a year. Back to their natural functioning, the restored wetlands are now able to cleanse the water before it is discharged into the bay. However, the expected results weren’t totally met since nutrient retention was still only around 10% at the project end.

Monitoring before and after implementation of the project

While setting the objectives, the Ministry of Environment and the regional environmental authority, Ringkjøbing County agreed to carry out a monitoring programme. This monitoring was actually included as an obligation in the Skjern River Act signed in 1987. The objectives of this monitoring were to evaluate the consequences of the project on the environmental and ecological qualities of the river system and the river valley within the project area. The monitoring was then part of the whole project. A precise description of this monitoring is introduced in two articles Pedersen, M., Andersen, J., Nielsen, K. & Linnemann, M. (2007) and Pedersen, M., Friberg, N., Skriver, J., Baattruppedersen, A. & Larsen, S. (2007) The monitoring plan was supposed to end in 2003. Nevertheless, the Skjern River is still currently monitored under the national environmental monitoring programme (NOVANA).

The monitoring tended to evaluate: effects on nutrient transport and retention in the project area, river morphology and habitats for macroinvertebrates, fish and macrophytes, vegetation in the river valley and amphibians, otter and migratory and breeding birds during the period 1999–2003. Some details of the monitoring are given below.

• The river morphology was studied before and after the restoration to describe the changes in river banks, water depths, the character of the river bed (mud, sand and gravel) and in the velocity of the water flow. Three reaches within the project area and one upstream reference site were studied.

• The river vegetation was monitored at the same sites as the morphology.

• Invertebrates were monitored in 2000 and 2003, before and after the restoration. The general biological quality of Danish rivers was used as index aiming to assess the occurrence of the river invertebrates. A quality index, Danish Stream Fauna Index (DSFI), was also used based on the invertebrates found. In very badly polluted streams the index value is 1, and in unpolluted streams with a diverse fauna the index value is 7.

• One of the aims of the project was to trap some of the nutrients (nitrogen and phosphorus) transported through Skjern River and thus reduce the nutrient load of Ringkøbing Fjord. Therefore, the nutrient concentrations and flow upstream and downstream the project area were monitored from November 1999 to December 2003 in the four main tributaries to the project area and in the two streams leaving the area as introduced in the picture below.

River monitoring stations for water quality and transport of water and nutrients (Pedersen, M., Andersen, J., Nielsen, K. & Linnemann, M. , 2007)

• The overall vegetation structure in the river valley was quantitatively monitored at 22 sites located in the western part of the restoration area in summer 2000 and 2003. More intensive monitoring took place at 3 existing nature areas close to the river and 2 protected areas in order to monitor possible ecological changes here as a consequence of the restoration.

• A monitoring of the occurrence of the otter was also carried.

• In the western part of the project area the occurrence of amphibians was monitored during the spring in 2000 and 2003. The monitoring was primarily through listening to the croaking and observations with binoculars.

• The impact of the restoration on the population of breeding birds was monitored by counting the birds in May-June in 2000 and 2003 before and after the restoration works in 2000-2002.

• Salmon population (smolt and adults) was also monitored

• The populations of sea lamprey (Petromyzon marinus) and river lamprey (Lampetra fluviatilis) were monitored in 2000 and 2002 by sampling sediment with a Kajak sampler to catch the lamprey larvae living in the stream bed.

Socio-economic aspects

In the following section, ways of cooperation, interaction and information with partners, stakeholders and wider audience of the project are introduced as well as their related success in reaching their participation objectives.

Cooperation

The Skjern river restoration project was led by the Danish National forest and Nature Agency in partnership with the National environmental research institute NERI which was in charge of the monitoring.

Interaction

Before launching the project, the Danish government established an advisory council with representatives from local and national authorities and NGOs which assessed the different restoration possibilities. The restoration project was actually under consideration for 12 years due to concerns about the environmental impacts of the drainage scheme and negotiations with private stakeholders. Farmers, fishermen, etc. were thus involved in the project design in order to adapt the measures according to their requests. This interaction led to the publication of a project proposal and an Environmental Impact Assessment in 1997 which included public ideas and proposals: the Parliament Act on Restoration of Skjern River.

Communication

Besides restoration work, recreational activities were also targeted through the development of “green tourism”. Therefore, recreation facilities were established in the project area such as 17.4 km of trails and 3 observation towers aiming to find the balance between protecting the natural area and allowing people to enjoy it. Furthermore, the Danish forest and Nature Agency published hiking guides, booklets, folders, organized meetings with the public and two nature centers opened in 2006. So far, the site has attracted an increased number of visitors and by the end of the project the beneficiary estimated that 350,000-400,000 people had attended the site.

Funding

The following section gives an overview of cost and funding of the project

The LIFE project cost about 7 millions € while the global project amounted to 38 million €. The European Union funded 30 % of the LIFE project while the Danish government funded the rest. Details are introduced in the table below.

Following the project a cost benefits analysis were carried by the royal Danish Agricultural University in order to find out the investment relevancy [1]. Although the agricultural was negatively affected by the project, the restoration of habitats increased retention of nitrates and phosphates in the restored valley and provided positive socio-economic effects such as fishing and recreation in the Ringkøbing Fjord. The following points were actually analyzed:

• Value as a factor of production (farm land, reed production, etc.)
• Ecosystem services (retention of nutrients, flood risk reduction, etc.)
• Consumptive outdoor recreation values (hunting, angling)
• Non-consumptive outdoor recreation values (hiking, boating, wildlife observation, etc.)
• Non-use value which individuals place on the mere existence of biological diversity.

The analysis concluded that the projects along the Skjern River were beneficial at an interest of 5 % or less on a 20 year time scale, and on an infinite time scale even at 7 %, i.e. a good public investment. It was also stated that the overall cost of the project (which is substantial) will be more than compensated for by the local economic opportunities generated through this work. This economical analysis can be used as a model for other river restoration project. It clearly demonstrated that investments in nature conservation and restoration have a potential to be beneficial long-term.

Contact person within the organization

Skov- og Naturstyrelsen, Danish Nature Agency
Niels Dahlin LISBORG, project manager
Telephone: +45 7254 3528
E-mail: ndl@nst.dk

Extra background information

Following the LIFE project, a management plan of the Skjern River (2005-2020) was set up to develop a consistent river basin management. Furthermore, the project’s beneficiaries, municipalities and local/regional NGOs foresee to launch the Skjern River National park in 2013 (actually expected by the end of 2006). The plan is to implement land use changes at a bigger scale thus leading to a more efficient re-establishment of natural processes through habitats improvement and species enhancement. Nevertheless, the agricultural opposing driving forces is still influent. More information available at [2] _{(language: english, abstract)}

References

• Project website
• Skjern River - Restoration of habitats and wildlife of the Skjern River _{(language: English)}
• ECRR-Addressing practitioners _{(language: English)}
• Restaurering af Skjern Å Sammenfatning af overvågningsresultater 1999-2003 _{(language: english, abstract)}
• Johannes Bach Rasmussen.(2005) THE SKJERN RIVER HISTORY OF THE RIVER VALLEY MAJOR PROJECTS THE NEW LANDSCAPE AND THE NATURE VISITING THE RIVER VALLEY. Danish Ministry of the Environment, Danish Forest and Nature Agency publication.
• Cost-benefit analysis of the Skjern river restoration in Denmark. Royal Veterinary and Agricultural University (2003) _{(language: English)}
• Cost-benefit analysis of the Skjern river restoration in Denmark. Royal Veterinary and Agricultural University (2002) _{(language: English)}
• Pedersen, M., Andersen, J., Nielsen, K. & Linnemann, M. (2007) Restoration of Skjern River and its valley: Project description and general ecological changes in the project area. Ecological Engineering, 30, 131 – 144 _{(language: English)}
• Pedersen, M., Friberg, N., Skriver, J., Baattruppedersen, A. & Larsen, S. (2007) Restoration of Skjern River and its valley - Short-term effects on river habitats, macrophytes and macroinvertebrates. Ecological Engineering, 30, 145 - 156. _{(language: English)}
• Andersen, J.M. (2005). Restoration of Skjern River. Summary of environmental monitoring results 1999-2003. 96 pp. NERI Technical report no. 531 _{(language: English)}

Related Measures

No measures have been assigned to this project.

Related Pressures

• Alteration of instream habitat
• Channelisation / cross section alteration
• Other pressures