Case study:Floodplain restoration in the River Traisen
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- 1 Project overview
- 2 Image gallery
- 3 Catchment and subcatchment
- 4 Site
- 5 Project background
- 6 Reasons for river restoration
- 7 Measures
- 8 Monitoring
- 9 Additional documents and videos
- 10 Additional links and references
- 11 Supplementary Information
|Project web site||http://www.life-traisen.at/lt/en/project-life-traisen|
|Themes||Environmental flows and water resources, Hydromorphology|
|Main contact forename||Gerd|
|Main contact surname||Frick|
|Main contact user ID|
|Contact organisation web site||http:///www.life-traisen.at/|
|Parent multi-site project|
| This is a parent project
encompassing the following
The River Traisen, one of the largest Danube tributaries in Lower Austria along the largest alluvial forest in Austria. However, the River Traisen is a heavily modified water body following the construction of the hydropower plant, Altenwörth, in 1976.
The regulated river is missing aquatic and terrestrial habitats that are usually found on flood plains. The connection between the river and the surrounding riparian forest is cut off. This situation leads to an unfavourable conservation status for the whole Natura 2000 site. High waters of the regulated Traisen rarely reach the surrounding habitats because of flood protection dams.
This project aimed to restore the River Traisen into a meandering river that is connected with the nearby wetlands of the Natura-2000 area of the Tullnerfeld floodplains, increasing habitats diversity and accessibility for fish.
Restoration actions involved: the (1) establishment of a meandering river to increase diversity of flow and habitats, the(2) creation of manifold structures in the water-land transition section of the river banks, the (3) creation of a floodplain along the new course of the river with frequently flooded sites, (4) to restore large-scale flooding zones and maintain the alluvial forest, connecting connect numerous floodplain, (5) construction of free passages in the river and cross-links on the floodplain area for fish and other water species.
Monitoring surveys and results
The project is expected to implement its measures on a 12.5 km stretch of the meandering River Traisen with dynamic banks and natural riparian forest areas. It is also expected to create a new running water habitat at mean-flow of some 69 ha, where dynamic riparian development can take place. It is expected that diversity in habitat types will increase from 6% to approximately 100%. At least 40 fish species will benefit from this measure, of which 25 species are listed in annex II of the Habitats Directive.
In 2009, comprehensive biological investigations took place in the floodplain area. A number of plant and animal species from eight specific categories were examined for the surveys on the current status with regard to the environmental impact declaration. In the process it was revealed that the area is much more diverse than originally assumed, based on the data available.
Catchment and subcatchment
Cost for project phases
Reasons for river restoration
Hydromorphological quality elements
Biological quality elements
Physico-chemical quality elements
Additional documents and videos