Breaking Ground on River Restoration Works at Paradeisinsel!

We are thrilled to announce the launch of restoration works onsite at our Upper Danube site at Paradeisinsel in the Donau-Auen National Park, Austria!

Photo L-R: Robert Tögerl (viadonau and Project Team Lead), Hans-Peter Hasenbichler (Managing Director viadonau), Elisabeth Wagnes (Mayor of Orth an der Donau), Peter Hanke (Minister for Climate Action, Environment, Energy, Mobility, Innovation and Technology), Edith Klauser (Head of the Nationalpark Donauauen), Helmut Habersack (BOKU/DANUBE4all Lead Coordinator), Karl Gravogl (Vorstand des NÖ Landesfischereiverbandes - Lower Austrian Fisheries Association ) and Johannes Wimmer (Österreichischen Bundesforsten - Austrian Federal Forests). Credit @ viadonau/Zinner.

Construction officially began with a ceremonial ground-breaking event on 6th March attended by Federal Minister Peter Hanke, National Park Director Edith Klauser, DANUBE4all project coordinator Helmut Habersack from the Institute for Hydraulic Engineering and River Research (IWA), viadonau CEO Hans-Peter Hasenbichler, ÖBf National Park Operations Manager Johannes Wimmer, and representatives from the nearby municipalities of Orth and Mannsdorf.

With support from the EU funding programmes Horizon Europe, INTERREG Slovakia–Austria, and the European Open Rivers Programme, project partner viadonau has begun work on the revitalisation of Paradeisinsel (Paradise Island) on the Danube, just east of Vienna. The project marks another important step in efforts to restore natural river processes along the Austrian Danube while balancing ecological goals with navigation and flood protection.

The initiative brings together scientific expertise and practical river engineering, with partners including DANUBEPARKS, Donau-Auen National Park, and a specialist planning office. Together, the project team aims to transform research findings into real-world restoration solutions that can serve as models for similar projects across the Danube basin.

Credit @ viadonau/Zinner and BOKU/O'Reilly

River Islands as Unique Ecological Refuges

River islands represent some of the most distinctive habitats within large river systems. Their position between the riverbank and the main channel creates sheltered zones that support diverse plant and animal communities. These areas often remain relatively undisturbed and provide valuable refuges for species typical of dynamic river landscapes.

At the same time, river islands also play an important role in the functioning of the river itself. Wave-protected areas can develop between the island and the bank, while the island helps maintain sufficient water depth within the main navigation channel.

Recognising their ecological and hydrological importance, viadonau and its partners have been working to protect, enhance, and in some cases recreate river islands along the Austrian Danube using innovative, integrated river engineering approaches. Recent projects have included restoration works at Marktau in Upper Austria and the Schwalbeninsel east of Vienna. The restoration of the Paradeisinsel near Orth an der Donau continues this effort within the free-flowing stretch of the Danube east of Vienna.

From Paradeisinsel to a Restored Island Landscape

The Paradeisinsel originally formed as a result of historic river regulation works designed to support navigation. Over time, however, sediment has accumulated between the island and the riverbank, gradually causing the channel behind the island to silt up. As this process continues, important hydrodynamic processes that support habitats for fish, birds, and aquatic plants are increasingly being lost.

The DANUBE4all restoration measures aim to reintroduce more natural river dynamics to the area. To this end, around 2.7 kilometres of hard bank reinforcement will be removed, allowing the shoreline to develop more naturally. In addition, groyne roots (the base/shore end of the wall) will be lowered to improve water flow while ensuring that navigation conditions remain unaffected.

A key part of the project focuses on enhancing the side channel behind the island, known as the Hinterrinner. Improving this channel will create sheltered habitats that provide ideal conditions for juvenile fish, helping to increase species diversity in the river. The works will also strengthen the connection between the river and its floodplain. By improving the exchange between surface water, groundwater, and the surrounding floodplain, the project will help restore natural water dynamics and increase the landscape’s ability to absorb floodwaters.

Reducing flow velocity in certain areas will also help counteract riverbed incision (vertical erosion of the river deeper in the riverbed channel) while supporting the maintenance of navigational depth for shipping along this important section of the Danube.

A Pilot for Future Restoration

Photo courtesy of BOKU/O'Reilly

The works at Paradeisinsel represent one of three pilot nature-based solutions being implemented along the upper and middle Danube. With a total construction budget of around €1 million, the project demonstrates how integrated river restoration can support biodiversity, strengthen flood resilience, and maintain navigation on one of Europe’s most important waterways. As work begins, the revitalisation of the Paradeisinsel offers a promising example of how research and practical action can come together to shape the future of the Danube.