Case study:Floodplain restoration in the River Traisen

Jump to: navigation, search
(0 votes)

To discuss or comment on this case study, please use the discussion page.

Location: 48° 11' 21", 15° 43' 0"
Edit location
Loading map...
Left click to look around in the map, and use the wheel of your mouse to zoom in and out.

Project overview

Edit project overview
Status Complete
Project web site
Themes Environmental flows and water resources, Hydromorphology
Country Austria
Main contact forename Gerd
Main contact surname Frick
Main contact user ID
Contact organisation Verbund
Contact organisation web site http:///
Partner organisations
Parent multi-site project
This is a parent project
encompassing the following
This case study hasn’t got a picture, you can add one by editing the project overview.

Project summary

Edit project overview to modify the project summary.

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

Edit project overview to modify the Monitoring survey 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.

Lessons learnt

This case study hasn’t got any lessons learnt, you can add some by editing the project overview.

Image gallery


Catchment and subcatchment


WFD water body codes
WFD (national) typology
WFD water body name
Pre-project morphology
Reference morphology
Desired post project morphology
Heavily modified water body
National/international site designation
Local/regional site designations
Protected species present
Invasive species present
Species of interest
Dominant hydrology
Dominant substrate
River corridor land use
Average bankfull channel width category
Average bankfull channel width (m)
Average bankfull channel depth category
Average bankfull channel depth (m)
Mean discharge category
Mean annual discharge (m3/s)
Average channel gradient category
Average channel gradient
Average unit stream power (W/m2)

Project background

Reach length directly affected (m)
Project started
Works started
Works completed
Project completed
Total cost category
Total cost (k€)
Benefit to cost ratio
Funding sources

Cost for project phases

Phase cost category cost exact (k€) Lead organisation Contact forename Contact surname
Investigation and design
Stakeholder engagement and communication
Works and works supervision
Post-project management and maintenance

Reasons for river restoration

Mitigation of a pressure
Other reasons for the project


Structural measures
Bank/bed modifications
Floodplain / River corridor
Planform / Channel pattern
Non-structural measures
Management interventions
Social measures (incl. engagement)


Hydromorphological quality elements

Element When monitored Type of monitoring Control site used Result
Before measures After measures Qualitative Quantitative

Biological quality elements

Element When monitored Type of monitoring Control site used Result
Before measures After measures Qualitative Quantitative

Physico-chemical quality elements

Element When monitored Type of monitoring Control site used Result
Before measures After measures Qualitative Quantitative

Any other monitoring, e.g. social, economic

Element When monitored Type of monitoring Control site used Result
Before measures After measures Qualitative Quantitative

Monitoring documents

Additional documents and videos

Additional links and references

Link Description proj id=3328 Life+ summary of the River Traisen project River Traisen project website Wise project description 2502 living-space-estuary-stretch-river-traisen Ecoweb project information

Supplementary Information

Edit Supplementary Information