Life in Upper Drau River

PROJECT DESCRIPTION

BACKGROUND

The Upper Drava (Obere Drau) Valley in Austria is the tectonic border between the Southern and Central Alps. The Drava River itself is typical of alpine areas. Formerly, the water system was much more diversified with side branches and alluvial waters, but these were modified to create a faster flowing, more homogenous river.

This project follows on from the successful LIFE project “Obere Drau - Restoration of the wetland and riparian area at the Upper Drava River" (LIFE99 NAT/A/006055), which terminated in 2003. It used engineering measures such as riverbed widening and removal of groynes and embankments along 60 km to allow riverbank erosion to occur and return the targeted stretch of the river to its former natural structure and creating new, or reactivating old, water meadows.

The Drava and its side arms are habitat for 19 autochthonous fish species, among others annex II species like the Danube salmon (Hucho hucho), varione (Leuciscus souffi) and bitterling (Rhodeus sericeus subsp. amarus). The river system contains highly endangered habitat types and is of national importance for Austria in view of nature conservation. It contains the largest Alnus incana alluvial forest (Grauerlen-Auwald) of Austria.

OBJECTIVES

The main objective of the project was to continue and extend the successful river-revitalisation measures to establish the Upper Drava as a ‘life vein’ for the region. Its efforts were to be focused on improving habitats which are typical for alpine rivers and their adjacent floodplains. It also hoped to improve public awareness and acceptance of the Natura 2000 area.

The project sought to define innovative management solutions to solve the challenges that were recognised, but not yet solved as part of the first LIFE project, such as:

Improved swell regime

Stabilised river bed and improved groundwater level

Continuation of management measures for the biotope system

Improving visitor information and developing visitor strategies on site

Co-operation with specialist agencies from countries bordering on the Drava.

It specifically hoped to use the Upper Drava as a pilot study providing a model for nature-orientated water management. It aimed to promote exchange of experiences across borders and propose cross-border strategies to solve water management tasks and ecological problems that affect the river. It thus sought to implement the cross-border requirements of the Water Framework Directive.

RESULTS

The LIFE Obere Drau II project provided an excellent demonstration of successfully meeting water engineering, flood protection and nature conservation objectives. The project improved the river course on a length of 5 km both improving the river ecology of the Drava River and the flood protection concept. The project also helped extend the Natura 2000 site ‘Obere Drau’ and nominate it as a bird reserve.

The project purchased or swapped over 14 ha of land to enable interventions in key locations. These focused on replacing hard embankments with gravel banks, restoration of a sediment retention dam, river widening and the connection of side channels, oxbows and standing waters in key places. In total, around 42 ha – 22 ha more than the target amount - of additional alpine river habitats were created including new side arms.

The new habitats, which include dynamic gravel banks (3220) and tamarisk and willow pioneer communities (3230, 3240), which will further develop to alluvial forests (91 E0) provide:

improved spawning habitats for amphibians and fish, in particular the Danube salmon (Hucho hucho), varione (Leuciscus souffia), European bullhead (Cottus gobio), Ukrainian brook lamprey (Eudontomyzon mariae) and Atlantic stream crayfish (Austropotamobius pallipes);

extended habitats for 140 bird species, including 51 on the red list – notably as a resting place for migrating birds crossing the Alps. Typical species that will benefit include the common kingfisher (Alcedo atthis), the common sandpiper (Acitis hypoleucos), the grey wagtail (Motacilla cinerea), the lesser spotted woodpecker (Dendrocopos minor) and the golden oriole (Oriolus oriolus);

extended habitats for two plants which were both nearly extinct in Austria: German tamarisk (Myricaria germanica) and the dwarf bulrush (Typha minima);

potential habitats for two bat species: Bechstein's bat (Myotis bechsteinii) and the Barbastelle (Barbastella barbastellus).

The project additionally created about 5 ha of alluvial waters, which connect biotopes for amphibians, such as the Italian crested newt (Triturus carnifex) and yellow-bellied toad (Bombina variegata). They provide important habitat for small fish species, such as the amur bitterling (Rhodeus sericeus) and crucian carp (Carassius carassius) and improve valuable food supply for the white stork (Ciconia ciconia). The European otter (Lutra lutra) was also found to have benefited from the project and settled again in the region.

Of particular importance was the International Drava River Symposia organised in Slovenia which led to a Convention regarding the future conservation of the river with all the countries through which it flows. The integration of the avalanche protection agency (WLV) in the project was also highly relevant for the wider catchment area management with reference to the sediment load in rivers. Public relations activities were well accepted by the local population.

Further information on the project can be found in the project's layman report (see "Read more" section).