Latest revision as of 08:43, 7 September 2011

Roermond – Restoring migration possibilities for 8 Annex II species in the Roer (LIFE06 NAT/NL/000078)

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The FORECASTER Team

Key features of the case study

In the following section, background and motives of the restoration project which led to the initiation of the project are introduced

Drivers and pressures

The whole Maas river system suffered for many decades from human activities, which altered the freshwater ecosystems. In order to control water flows and produce electricity, various barriers such as hydropower plant were established along rivers of the basin thus resulting in the closing-off of the North Sea from the main rivers. This closing-off prevented fish to migrate upstream to the spawning grounds. For that reason, several projects were undertaken aiming to eliminate fish migration barriers in the Maas river system by different means (bypass, ladder, dam removal, etc.). Nevertheless, despite this undertaken work, there were still two remaining fish migration barriers in 2006 in the Roer River: in the Molentak branch of the Roer near the Electric Chemical Industry plant in Roermond and the near the dam in the Roertak.

Global objectives

The aim of the LIFE project was to create a single accessible river system from the North Sea to the streams and brooks of the upper Roer in Germany since these two structures overcame the last remaining obstacles for fish migration between the river Mass and the Dutch part of the river Roer.

By improving the Roer river continuity, the project also aimed to restore endangered species such as the Atlantic salmon (Salmo salar) and other Annex II species, namely asp (Aspius aspius), bullhead (Cottus gobio), river lamprey (Lampetra fluviatilis), brook lamprey (Lampetra planeri), sea lamprey (Petromyzon marinus), bitterling (Rhodeus sericeus susbsp. amarus) and weatherfish (Misgurnis fossilis). Besides, by restoring Habitat Directive species, the water board reinforced the status of the Roer valley as a Natura 2000 area.

Specific goals

The project foresaw to remove the last obstacles to fish migration in the Roer by constructing a new fish ladder in Roermond and modifying an inefficient fish ladder built in the 1980’s “the green overfall” in the Hambeek; thus opening the Roer to migratory fish all the way to Germany.

Site description

Measures selection

The following section introduces which measures were prepared, implemented and whether they were successful in reaching their related goals

In the frame of the LIFE project, two measures were implemented at two different sites (see Google map above).

• The building of a new fish ladder in Roermond going via a series of switchbacks (a height of 2.4 m and covers an area of 2 000 m2) to allow fish to migrate upstream to the dam. The fish ladder could also be used for downstream migration. Therefore, a protective grill was installed above the hydropower installation to avoid fish swimming towards the hydro installation to be killed or injured in the turbine.

• The existing fish ladder at Hambeek was improved to increase its effectiveness (480 m long and bridges a height of 2.5 m). Modifications were made to allow all fish species to migrate through the fish pass since the ladder steps were actually too high for some migratory species. Besides, the fish entrance was moved to ensure that fish migrating upstream can find the entrance of the fish ladder even during periods of high flow.

Success criteria

No information found

Ecological response

Monitoring has confirmed that three of the species targeted by the project (salmon, sea lamprey and European bullhead) are using the new Roermond fish ladder. Salmon and sea lamprey have also been recorded using the improved Hambeek migratory facilities. Those results were especially highlighted through an electro-fishing carried out in 2008 which caught hundreds of fish of 27 different species in the fish pass.

Hydromorphological response

Monitoring before and after implementation of the project

Roer fish population was assessed before the restoration especially through the fish stock survey performed in 2003 that was used as a baseline for the project. The need for fish ladders near to the current dams was brought up through this assessment leading to the implementation of the project.

After the restoration, both monitoring physical and ecological were carried to find out whether the restoration was a success.

• First of all, studies were carried to establish how well the passes and constructions are working. Flow speeds and the way the current divides were monitored at different places.

• Then, the Waterschap Roer and Overmaas Regional Water Authority undertook fish stock inventories to look at the effectiveness of fish ladders on the basis of the numbers and species of fish passing the ladder in either direction by trapping fish swimming through the ladder (gage traps). The best times to measure are during the spring (March, April and May) and in the autumn (October, November and December). Besides, early in January 2008, the Hambeek and the renovated fish passage between the Roer and the Hambeek were electrically fished.

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 LIFE project was initiated by the Waterschap Roer and Overmaas Regional Water Authority.

Interaction

Several stakeholders were involved in the project especially those who are the most affected by fish species disappearance. Anglers and other volunteers thus helped carrying the fish monitoring (Valley Fish Stock Management Committee-Visstand beheerscommissie).

Communication

Besides fish ladders construction, education and informing was another desire of the project board. Project managers foresaw to share freshwater knowledge and experience to a large broad of audience through:

• The development of a website
• The installation of a visitor centre with an underwater viewing window at the new fish ladder at the ECI hydropower.
• Excursions, meetings and project presentations for local people but also for environmental and nature organizations.

Funding

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

Cost: 3 187 646 Euros
European Union: 40 %

Contact person within the organization

Waterschap Roer en Overmaa
Peter BROUWERS, project manager/coordinator
Telephone: +31 46 420 5700
E-mail: p.brouwers@overmaas.nl

Extra background information

• LIFE Nature Project - Roer Migration - After LIFE Conservation Plan (2009) _{(language: Dutch)}

References

• Project website _{(language: english, abstract)}
• LIFE Web summary _{(language: English)}
• Layman’s report (2008). Life-nature project - Restoration of fish migration in the river Roer _{(language: English)}

Related Measures

• Facilitate downstream migration
• Install fish pass/bypass/side channel for upstream migration

Related Pressures

• Artificial barriers downstream from the site