LIFE PROJECT: Restoration of Austrian Danube floodplain and river banks

The Donau-Auen National Park, east of Vienna in Austria, includes one of the last major alluvial floodplain areas in Europe and one of the largest and best-preserved regions of lowland riparian forest in Central Europe. The national park was created in 1996 to conserve the floodplain. The former flooding regime of the Danube favoured an extreme range of water level conditions, with associated high biodiversity. However, the river’s hydro-dynamics were affected by the construction of several kilometres of flood-alleviation embankments and navigation structures, such as weirs, along the course of the river, which resulted in changes in the river’s natural course (with meanders and branches straightened and re-directed).

This disconnection between the river and its floodplains and consequent alteration of the duration and frequency of flooding had caused the drying up of former wetlands with a severe impact on the ecosystem. In order to secure and restore riverine habitats and to improve the lateral river floodplain connectivity, a set of measures was conceived by biologists and river engineers. The aim was to show, through the implementation of pilot projects, that such measures are effective and compatible with the requirements of navigation and the existing flood protection scheme.

In the first LIFE project, two larger cutoff side channels were reconnected to the main river by removing all dams and changing existing weirs to bridges to permit flow out of the main channel into the adjacent forests and former side channels.  In the second LIFE project, a 3 km pilot section of "hard" river bank enforcement (i.e. stones and boulders) was removed to allow full lateral bank erosion. This type of action had never before been implemented on a major European navigation route.  According to project manager, Carl Manzano, changes in river morphology "were impressive" and endangered species – for example, Charadrius dubius and Actitis hyploeucos – have reacted promptly and favourably to habitat improvement.

A key aspect of the projects was that they fostered a successful partnership between the National Park Administration and the Danube Waterways Authority who jointly planned, implemented and monitored the works. The experience gained was invaluable in the design of an ambitious new general engineering project for the whole national park area. This project combines improvements to navigation with large scale reconnection of side channels and the removal of river bank enforcement along the whole 36 km reach of the Danube.

Inland waterway authorities

Even on a major international navigation route such as the Austrian Danube there is a surprisingly high potential for river revitalization. The actual physical implementation of pilot projects in a step-by-step approach is the best way of overcoming the doubts of experts, authorities, stakeholders and the general public. LIFE programme funding allowed the national park to act on an equal footing with the Waterways Authority and thus establish a lasting partnership.

For more information go to http://ec.europa.eu/environment/life

Project number: LIFE98 NAT/A/005422 and LIFE02 NAT/A/008518

Title: Restoration and management of the alluvial flood plain of the River Danube

Beneficiary: Nationalpark Donau-Auen GmbH