Environment

Restoring the Upper Drava river

13/02/2015

LIFE projects encouraged cooperation among water engineering, flood protection and nature conservation authorities to help restore the Upper Drava river in Austria.

Once a natural watercourse, the Obere Drau (Upper Drava) river in Carinthia (Austria) had been significantly altered over the years – the river bed channelled, bends straightened, branches cut off from the main stream, dams and turbines built, and intensive farming extended to the river banks. But a LIFE river-restoration project has brought about a marked improvement in the conservation status of riparian habitats and the species they host in the Obere Drau. It has also boosted ecosystem services provided by the river, such as water retention, and improved river connectivity to establish ‘blue and green’ infrastructure.

Following severe flooding and falling groundwater levels, the Austrian authorities decided on a new approach back in the 1990s. They began restoring the river to a semi-natural state, addressing the surviving grey alder and ash forests along the banks, as well as the small populations of fish species listed in Annex II of the Habitats Directive, the Danube salmon (Hucho hucho) and white-clawed crayfish (Austropotamobius pallipes).

Further restoration of the Drava – in partnership with river and flood protection authorities –continued under the LIFE programme. The Obere Drau II project ran from 2006 to 2011, following on from an earlier project that ended in 2003. Coordinated by the department responsible for rivers within Carinthia’s regional government, the project included measures to widen the river and remove hydraulic structures and embankments, allowing for natural erosion. It also created and restored water meadows.

A key achievement was the doubling in size of the existing Natura 2000 site to over 1000 hectares – and enhancing public acceptance of the site. Hard embankments were replaced with gravel banks, a sediment-retention dam was restored, and the river was widened and reconnected with side channels, oxbows and standing water areas.

Around 42 hectares of additional Alpine river habitats were created, including dynamic gravel banks and German tamarisk (Myricaria germanica) and willow communities, improving spawning habitats for amphibians and fish species. Another result was extended habitats for 140 bird species, notably as a stopover for migrating birds, with 20 ponds created to connect biotopes for amphibians, to host small fish species and provide food for the white stork (Ciconia ciconia). The European otter (Lutra lutra) has settled in the region again, and the project has also established barbecuing, hiking, cycling, canoeing and fishing along the restored river.

 

Funding and LIFE