With the conclusion of the first evaluation phase of the Pilot Project Bad Deutsch-Altenburg in 2016, the conceptual and pilot project phase of the Integrated River Engineering Project for the Danube East of Vienna was brought to an end. On the basis of the findings, as well as developments in waterway and traffic management, a new direction is now taken with the Catalogue of Measures, drawn up to achieve ecological and nautical conservation targets on the Danube east of Vienna.
Initial success in the reduction of riverbed erosion
The latest analyses of the development of the riverbed on the Danube east of Vienna between 1996 and 2016 show that erosion of the riverbed declined significantly in the second decade of the survey period. The annual gravel deficit has decreased by more than 40 per cent. The reasons for this are the pilot projects at Witzelsdorf and Bad Deutsch-Altenburg, as well as a modified maintenance strategy. Since 2009, gravel, which is dredged during the course of maintenance work, is systematically shipped upstream and dumped there. From 2015 onwards, average distances for the transportation of material relating to riverbed management have increased significantly (approximately 10 kilometers on average), meaning that the gravel remains substantially longer in the section of the Danube.
Combined gravel deficit east of Vienna 1996-2016 (profile distance 100m)
The annual gravel deficit decreased by over 40 per cent between 2006-2016 compared to 1996-2006.
- Continuous bedload management
In 2016, 273,000 cubic meters of gravel were dredged and transported an average of over ten kilometres upstream before being returned to the river. As a result, on the one hand minimum fairway parameters for navigation were by and large achieved. On the other hand, the gravel remains substantially longer in the section of the Danube. This represents a major contribution to the stabilisation of water levels. Since summer 2017 the operation of a bed load trap was started in the area of ford Treuschütt in order to gather gravel for bed load management and to further improve the fairway conditions in this section. In this context 80,000m³ of Danube gravel were dredged in 2017 and transported around 20 km upstream, where they were deposited in two critical areas of riverbed erosion. This measure also contributes actively to the dynamic stabilization of the Danube’s river bed as well as its’ water levels.
- Revitalization of the Fischa’s river mouth (INTERREG SK-AT)
In the frame of the INTERREG project Alpine Carpathian River Corridor viadonau implements the revitalization of the river mouth of the Danube tributary ‘Fischa’ in Lower Austria. Works have been started in fall 2019. By removing riverbank reinforcements on both banks, the river mouth is returned to a more natural shape and improved ecologically. Significant steps towards the improvement of the habitat network of the Danube are made. Read more in our project database.
- Island Wolfsthal
By lowering existing groyne parts in its’ riparian vicinity, a back channel will be created in the area of river-kilometer 1877. Thereby a small side arm shapes between an existing gravel bank and the main stream of the Danube River, forming a valuable wave protected area as well as strengthening the character of the gravel bank as an island. The island will represent an important refuge area for animals of the Danube wetlands. First activities have successfully started in fall 2018. The measure is implemented in cooperation with the project DANUBEparksCONNECTED (Interreg DTP - Programm), leaded by the Donau-Auen Nationalpark. Find more information about the project here.
- Christian Doppler Laboratory sediment research and management
Within the frame of a research cooperation with the University of Natural Resources and Life Sciences, Vienna (BOKU) scientific accompaniment and monitoring of measures is carried out. The laboratory especially tackles the questions about sediment management (e.g. material composition and quantities, sediment abrasion) in the context of river bed degradation and tries to further understand morphodynamic processes of the Danube River.
- Ongoing planning activities
Planning and preparatory work for many individual measures listed in the Catalogue of Measures are in progress. At the moment the planning of side arm re-connections at Haslau-Regelsbrunn and of the Spittelauer Arm opposite Hainburg is in progress.
- Evaluation of project impacts
For the pilot projects Bad Deutsch-Altenburg and Witzelsdorf studies are being undertaken to determine the medium and long term effects of the construction measures on the Danube, as well as on plants and animals of the Danube floodplains.
- Optimization of groynes at Treuschütt
Ford Treuschütt was considered to be one of the Danubes’ critical sections for navigation, restricting the available fairway depth for inland waterway transport in Austria. With the optimization of the existing low water regulation structures in august and september 2018, the minimum fairway parameters were achieved and the riparian area ecologically improved.
- Relocation passenger landing stage Hainburg
With the relocation of the existing passenger landing stage at Hainburg the safety of navigation in the Danube section east of Vienna was improved. Mooring vessels no longer protrude into the navigation channel and represent an obstacle for traffic. Furthermore, it was possible to move the navigation channel towards the natural depression zone of the river bed, reducing the efforts for maintaining safe and economic fairway conditions.
- Christian Doppler Laboratory "IM Fluss":
Scientific accompaniment and monitoring were carried out in particular by the Christian Doppler laboratory "IM Fluss" (Innovative methods in river water monitoring, modeling and river engineering). For further information, please visit: http://www.cdlabor-imfluss.boku.ac.at/.
- Optimisation of the ford at Bad Deutsch-Altenburg:
At the beginning of 2017, fairway navigability was significantly improved by the adaption the groynes at the ford at Bad Deutsch-Altenburg, leading to reduced maintenance costs. The objective was to create defined minimum water parameters in the fairway (a fairway depth of 2.50 in accordance with the low navigable water level regulation LNWL) as well as to approach a balanced state between sedimentation and erosion of the riverbed.
- Pilot test bedload management:
Bedload management was tested in 2015 with some 68,500 cubic meters of gravel, which were transported more than 18 kilometers upstream. The focus of the investigations was on the effects this management approach had on the riverbed, along with economic aspects, considering cost of implementation, equipment used, weekly performance, etc.
- Optimisation of the ford at Petronell:
In autumn 2015 the groynes and the training structure at the ford at Petronell were raised slightly in order to eliminate the previously deposited accumulation of gravel in the fairway. The objective was to create defined minimum water parameters in the fairway (a fairway depth of 2.50 in accordance with the low navigable water level regulation LNWL) as well as to approach a balanced state between sedimentation and erosion of the riverbed.
Pilot project phase
Completed conceptual and project phase pilot projects
- Pilot Project Bad Deutsch-Altenburg:
Construction completion in 2014; TEN-T project
- Pilot Project Witzeldorf:
Construction completed in 2009; TEN-T project
- Riverbank restoration Thurnhaufen:
Completion 2006; LIFE project in cooperation with the Donau- Auen National Park
- Side-arm reconnection Schönau:
Completion 2004; LIFE project in cooperation with the Donau- Auen National Park
- Side-arm reconnection Orth:
Completion 2002; LIFE project in cooperation with the Donau- Auen National Park
- Side-arm reconnection Haslau-Regelsbrunn: