LIFE Nature Project, Austria: Restoring the river Lech

The Lech valley is one of the most beautiful areas in the Alpine region and home to a Natura 2000 site of 41.4 km2. The area is relatively close to nature and hosts a wide range of bird species. However, the construc­tion of dams for flood protection and the practice of gravel extraction have radically altered the river in many parts in the last centuries. Such inter­ventions have deepened the riverbed and lowered the water table.

As a result, flooding occurred less often and riparian pine tree for­ests prospered at the expense of more 'natural' shrubs, such as the German tamarisk (Myricaria germanica), which thrives on gravel banks. This more open habitat is home to the very rare pink-winged grasshopper (Bryodema tuberculata) and bird species such as the little ringed plover (Charadrius dubius).

To stop further erosion of the riverbeds and increase the bedload of the river, the regional governmental department responsible for environmental protec­tion (Amt der Tiroler Landesregierung) began a LIFE project in 2000. Reinhard Lentner, project leader, says: “One of the first steps was to open up the dams to allow bedloads to follow the river without any blockages.”

Measures were also taken on tributar­ies to the Lech. At Hornbach Sperre, actions carried out by the project have had a dramatic impact on the appear­ance of the river. A dam built 40 years ago, following the flooding of the vil­lage, has been removed and display boards clearly show the impact on the water levels and the widening of the river. "The dam kept the river in the middle [between the banks] and it dug in. They were too successful," explains Lentner.

The Hornbach action demonstrated an important feature of the project: the involvement of local authorities in fos­tering local acceptance of the project's aims. The water management authority (Bundeswasserbauverwaltung) and the forestry and avalanche control author­ity (Forsttechnischer Dienst für Wild­bach- und Lawinenverbauung Tirol) were project partners. "It was impor­tant to have these bodies involved because the local people trust them more than the conservationists," says Lentner.

Another key management consideration concerned the extraction of gravel from the river. Several companies extract and sell the gravel, but to minimise the impact of this, the project carried out research to determine where this practice is least detrimental to the river flow. The impact of gravel extraction was also lessened by the use of special traps that avoid the need to dig into the river bed. The gravel companies were amenable to changing location as extraction at the designated places was cheaper than where it was previously carried out. Gravel traps were also a necessary management measure in certain parts where flooding is not desirable. 

Actions were also carried out on brooks and ditches. At Haeselgehr, drainage of pasture land through the construc­tion of ditches led to the silting up of a small tributary stream. A popular meas­ure of the project, which was widely supported by locals, was to restore this stream to its former condition and reconnect it to the Lech. The restored ecosystem offers valuable services to the community: cattle can now use the stream and no longer require artificial watering facilities, and fishing is pos­sible. In fact, the removal of fish barriers was an integral part of the project. At Haeselgeher, for example, a tube tun­nel was replaced with a small bridge to facilitate the movement of fish.

In this way the project adopted a holis­tic approach to river restoration, creat­ing a mosaic of habitats of ecological importance. For example, small riverside ponds, which are home to a range of amphibians, and the highly endangered dragonfly species (Coenagrion hylas), were created or restored – around 40 in total. Measures were also taken to protect insects. For example, a total of 98 light bulbs in existing lamps were replaced by insect-friendly bulbs.

Water authorities, forestry authorities, local landowners and other stakeholder groups

The Tiroler-Lech project was particu­larly large in scale – the target site was a 6 km stretch of river. River restora­tion measures were also carried out on the Vils. Reinhard Lentner believes that restoration on such a scale was only possible due to the region's vast undeveloped areas. "Here we still have the opportunity to do this kind of work, but in many areas of Europe you don't, because there are constraints," he says.

Lentner adds, however, that his team seriously debated whether to remove the riparian forests that had become established as a result of the lack of flooding. However, the decision was taken to restore the banks to a more natural condition (around 10 ha of pine forest were removed but many hectares remain) and compensation was paid to foresters to improve con­ditions for bird species dependant on dead wood, such as the grey-headed woodpecker (Picus canus) and the white-backed woodpecker (Dendro­copos leucotos).

At Johannesbrueke, such manage­ment actions have lead to a consider­able widening of the river. The bridge crossing the river was only a half as long as it is now, according to Lentner. In fact, he says that the bridge, which was no longer resting on its pillars, was "one of the reasons that we wanted to carry out the project". The construc­tion of a new section of the bridge was a necessary part of the project. Widen­ing of the river decreases the speed of the water flow and lessens erosion.

Public awareness-raising initiatives carried out by the project included schools competitions, training for nature guides and a time-lapse movie. Moreover, good co-operation among the beneficiary and its partners (including the WWF) was established. At Pflach, an observation tower was erected. The site is particularly inter­esting for birdwatchers as it features many of the different biotypes of a mature river system, according to Lentner. Here, small ponds were cre­ated and spruces removed to create a rich natural riparian habitat.

For more information go to http://ec.europa.eu/environment/life

Project number:            LIFE00 NAT/A/007053

Title:                             Tiroler Lech - Wild river landscape of the Tyrolean Lech

Beneficiary:                   Amt der Tiroler Landesr­egierung, Abteilung Umweltschutz