Unterwasseransicht eines Fischschwarms in der Leitha.

Living Leitha

Three measures for a healthier Leitha in Lower Austria and Burgenland

Ein naturnaher Fluss mit wichtigen Lebensräumen für Tiere und Pflanzen und neuen Rückzugsorten für Menschen, die die Natur genießen möchten.

The Leitha awakens to new life!

Since 2023, the river is being revitalised in several sections in Lower Austria and Burgenland – creating structurally rich and lively river sections.

The first measures have already been completed. Until 2026, the river’s appearance will continue to change as a result of the other planned measures. Step by step, a more natural river will be created with important habitats for animals and plants and new quiet spots for people who want to enjoy nature.

Leitha Lower Austria Fact Sheet

Total construction costs

Mil €

Measure 1 Total Costs

Mil €

Measure 2 Total Costs

Mil €

Measure 3 Total Costs

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Construction Period

Oct 2023

1st Quarter 2026

Three Revitalisation Measures

Structural improvement in the residual water section Trautmannsdorf near Bruck a.d. Leitha

Reconnection of the ‘Haidmühlarm’, an old river branch near Rohrau

Construction of a ‘fish rescue pool’ near Lichtenwörth

Change of perspective

Experiencing the Leitha by canoe or kayak gives you a completely different perspective. Once on the water, an entirely new world opens up. The river is easily accessible in many places and the beautiful nature and impressive riparian forests create a unique atmosphere.

Structural improvement in the residual water section Trautmannsdorf near Bruck a.d. Leitha

Measure 1 in the spotlight

In order to turn the Leitha into a structurally rich river with many different habitats, structural measures such as groynes and the installation of deadwood packages are being implemented in various sections.

This will create pools, fords and gravel banks. Low weirs are removed and a low water channel is structured and designed.

Example

In the Bruckneudorf/Bruck area, 5 non-passable weir structures are being converted into groynes.

Buhne an der Leitha, die im Rahmen des IRIS-Projekts als strukturverbessernde Maßnahme umgesetzt wurde.

Reconnection of the ‘Haidmühlarm’, an old river branch near Rohrau

Measure 2 in the spotlight

By reconnecting the Haidmühlarm, a silted-up tributary of the Leitha, a monotonous and heavily regulated section of the Leitha was restored towards its former natural state. The construction work has already been completed.

Luftansicht des Haidmühlarms vor Umsetzung der Revitalisierungsmaßnahme an der Leitha bei Rohrau.

Luftansicht der Revitalisierungsmaßnahme an der Leitha bei Rohrau nach Wiederanbindung des Haidmüharms.

Construction of a ‘fish rescue pool’ near Lichtenwörth

Measure 3 in the spotlight

In months with little precipitation, sections of the Leitha between Katzelsdorf and Lichtenwörth may dry up completely. To enable fish to survive during such periods, a so-called fish rescue pool is being created as a test. This is an approximately 1.5 metre deep depression in the river bed.

The installation of a stone groyne is intended to ensure that this depression is preserved in the long term. If there is no fresh water supply for a longer period of time, fish can be retrieved by the local fisheries in an emergency and transferred to the sections with water. The material excavated from the pool was used to create gravel habitats in the shallow bank zone.

Baumaschine an der Leitha mit zwei Personen. Hier wird ein Fischrettungspool angelegt.

Timeline: Revitalisation Measures on the Leitha - Lower Austria

Why are revitalisation measures being implemented on the Leitha?

The aim of the LIFE IP IRIS project is to harmonise flood protection with ecological objectives. This is achieved primarily through the use of nature-based solutions. Therefore, the IRIS project uses revitalisation measures to bring parts of rivers back towards a more natural state.

Monotonous river landscape

In the past, river straightenings and regulations have led to lively, species-rich rivers becoming monotonous water bodies. On the Leitha, the combination of river regulation, power plant operation, river diversions and also the strong natural seepage of the Leitha into the gravel body in some sections has resulted in shallow and monotonous sections. Long and monotonous residual water stretches characterise the image of the Leitha in many places. Today, there is not much left of the once meandering river.

Structural improvements

The revitalisation measures on the Leitha are aimed at improving the available structures in these heavily modified sections of the river. The watercourse structures are optimised taking into account the existing general conditions. While most IRIS measures focus on widening watercourses, such an approach would be rather counterproductive for the Leitha. This is because the already shallow water depth would decrease further, particularly in the residual flow stretches, which would have negative consequences such as increased warming and restricted river connectivity.