LIFE+ Traisen: Success of the project

The new Traisen river is now also the connection to the Danube through which fish can pass unhindered. It is free from obstacles and has a natural design. The main objective of the project was to improve the habitat situation in this part of the European conservation area “Tullnerfelder Au”.

Traisen project area

The LIFE+ project implemented a set of measures in the area between the Danube and the former Traisen canal to create a whole new Traisen river over a distance of approx. 10 km, with surrounding bank zones and a large estuary at the Danube. Around Altenwörth power plant, the waters of the Traisen were diverted into this new river bed. The old channel was retained to provide relief during very high floods and as a body of standing water. The LIFE+ project created the NEW lower course of the Traisen, which is not a revitalisation of an old section of river, but the creation of a new dynamic river and wetland habitat.

New flowing waterbody

The creation of the new, 10 km-long, meandering Traisen river with dynamic banks and intensive interplay of water and land is complete and should continue developing dynamically and naturally. New running water habitats covering approximately 30 ha (under mean-flow conditions) were created.
Flood zones covering an area of 60 ha were actively created on the new river. They are the location of the priority habitat for the silver willow wetland, which is part of FFH type 91E0*. These riparian forests are typical of the area. According to the experts, the young riparian forests are developing very well and will eventually achieve their typical form. Willows and poplars established themselves independently on the new bank zones and enrich these typical river habitats in the Natura 2000 area by around 5%

New wetland ponds

Bodies of standing water have been created along the new Traisen and in the adjacent wetland area. These are large waterbodies, so-called wetland ponds, with natural bank zones as well as amphibian zones with shallow and temporary water areas. Overall, the work led to the enrichment of the variety of waterbodies in the wetland area by 15 hectares.

Fish-friendly measures

With the new Traisen, the project created a fish-passable network, which nowadays connects the wetland area and its many waterbodies, the Traisen river and the Danube. Fish are able to pass through the new Traisen river unhindered at all times. The associated fish migrations and improvements in fish stocks are also having a lasting impact on the fish fauna in the Danube. 39 autochthonous species of fish, including 11 FFH Annex II species, had already moved into the habitats by 2019. The species migrated not only into the new section of river, but also thrived in the new Traisen.

Late summer impressions of the Traisen

Meadows and dry areas

The project also resulted in a permanent improvement in the conservation status of typical meadowscapes in the wetland area. These natural meadows, which are designated as dry grasslands, belong to flora-fauna habitat type 6210* and are now available to many rare types of fauna and flora on an area of 30 hectares. 
The project battled unwanted plants, so-called neophytes, on an area of 25 hectares in the new section of river and on the meadows with lasting success. Naturally, only mechanical methods were used. This way, the goldenrod could be almost entirely removed from the meadows.

Maintenance and upkeep

As all ecological effects and the natural dynamics also had to be ensured on a permanent basis, agreements were concluded on tolerance and on permanent maintenance measures. Most measures took place on third-party land, so the land owners were compensated for various pecuniary disadvantages. That was the basis for implementing the project. This financing was processed without the utilisation of LIFE monies.

The river landscape will now continue to develop naturally and undisturbed. Nature itself can create new habitats and change old ones. The positive ecological consequences of the new Traisen can be felt far beyond the project’s limits and are sustainably effective.