The Carpathians and the Alps belong to one of Europe’s most important natural areas. The designation of the Alpine Carpathian Corridor ensures the continuity of this precious ecological network.

In the framework of the project “Alpine Carpathian River Corridor” the habitat network of aquatic organisms in the Slovakian-Austrian border area shall now be protected and improved.

The protected areas (Danube wetlands, Zahorie, the Vienna Woods, Morava) close to the cities of Vienna and Bratislava serve as important areas for nature conservation and also recreation. These protected areas nevertheless can only achieve their goal of protection if their connection is ensured via natural corridors. In this context the network of watercourses and streams plays a major role. Unfortunately their multi-functionality is compromised by regulating and transverse structures, poorly structured alluvial forest and intensive agriculture in the surrounding areas.

Main objectives

  • Strengthening the habitat network of the Alpine Carpathian Corridor and enhancement of rivers as ecological corridors through the implementation of revitalization and other habitat improving measures.
  • Increasing of efficiency and coherence of protected areas and Natura 2000 in the Slovakian-Austrian border region through transnational experience exchange and elaboration of common standards and concepts.
  • Mid-term and long-term assurance of habitat improving measures in the Alpine Carpathian River Corridor through awareness raising in public and anchoring this initiative on the eco-political agenda.

Project outputs

  • Feasibility study and action plan – role of rivers of the Slovakian-Austrian border area for the advancement of the Alpine Carpathian Corridor
  • Transnational revitalization concept for rivers of the Alpine Carpathian River Corridor

Design and implementation of 13 pilot measures to restore and revitalize rivers and streams within the Alpine-Carpathian region to improve the quality of habitats and to strengthen the habitat network as well as secure their experiential value:

  • Implementation of different options of river revitalization (e.g. riverbank renaturation, river bed widening) and habitat improvement for the rivers ‘Schwechat’, ‘Fischa’, ‚Rudava‘ and the catchment area of ‘Mociarka‘ and ‘Malina‘ together with local, national and transnational stakeholders.

Documentation and presentation of project achievements by flagship- and indicator species:

  • Implementation of conservation measures for selected species such as the Dice Snake, Kingfisher, Nase together with volunteers, schools, NGOs, and municipalities.
  • Monitoring and evaluation of project goals


Role viadonau - Revitalization of the Fischa’s river mouth

viadonau is responsible for planning and implementing the revitalization of the Fischa estuary in Lower Austria. The river Fischa is a tributary of the Danube. Two revitalization phases are planned, the first of which was already successfully completed at the end of 2019.

In the autumn and winter months of 2019, viadonau implemented river engineering measures for the natural redesign of the river banks at the mouth of the Fischa. While the construction of riverbank enforcement along the Danube bank was lowered over a length of 125 meters upstream, about 130 meters of blocks were completely removed downstream. The embankment protection of the Danube reached on both sides into the mouth area of the Fischa. The newly designed estuary allows the Danube and Fischa to develop dynamically on their own and to develop natural bank structures.

In September and October 2020, the second phase of revitalization was conducted and a biotope created. The level of the area behind the bank upstream of the estuary was lowered in such a way that a flat side arm is created with an intermittent downstream connection to the Fischa River. The affected area used to be a waterbody and was filled with Danube gravel in the course of waterway maintenance in the past. The Danube gravel present there was removed and brought back into the bed load cycle of the Danube. The measure can significantly improve the water connection and thus create aquatic and semi-aquatic habitats, especially for juvenile fish and amphibians as well as macrozoobenthos and water birds. This area is also where the Common Nase and Barbel come together annually before they are heading further upstream into the Fischa.

Find out more about the finalisation of the second revitalization phase and its measures under this link.

The aim of both hydraulic engineering measures is the extensive restoration of the site-typical river-, alluvial- and bank-structures as well as fish-ecological improvements (including making the spawning areas in the Fischa more attractive). Flat, natural gravel banks, such as those created by the removal of the block stones in the area of the mouth of the Fischa, are essential for native rheophilic fish species that need the well-flowed gravel gap area of the river bed for their spawning activities. Together with other measures, the project contributes to the ecological improvement of the Fischa-Danube habitat network.

Implementation period of the measures:

  • Revitalization phase 1 - bank removal, October to December 2019
  • Revitalization phase 2 – biotope, September to October 2020

These measures are element of the Catalogue of Measures for the Danube east of Vienna.


The bilateral project ‘Alpine Carpathian River Corridor’ is implemented by 7 partners from both Austria and Slovakia and 10 strategic partners:

Project partner:

The following strategic partners have a supporting role and represent important multipliers for the project work:

Duration and budget

Project duration: 01.09.2017 – 28.02.2021

Budget: EUR 2.1 Mio.
EU-funding (ERDF): EUR 1.79 Mio.


  • Provincial Government of Lower Austria – department conservation
  • Schwechat Water Association