PROJECT DESCRIPTION
BACKGROUND
The River Enns in Styria, Austria, meandered extensively in the past, but over the last few centuries it has been increasingly straightened, leading to the loss of many freshwater habitats and alluvial forests.
OBJECTIVES
The main objective of the WeNatureEnns project is to restore the riparian corridor and ecosystem functions to approximately 20km of the River Enns. The vast majority of actions take place in three Natura2000 sites ‘Ennstal zwischen Liezen und Niederstuttern’, ‘Ennsaltarme bei Niederstuttern’ and ‘Gersdorfer Altarm’.
The specific objectives of the project are to:
- improve ecological coherence and conditions for protected habitats and species, mainly focused on lowland hay meadows, alluvial forests and riparian mixed forests
- preserve biodiversity and implement the requirements of the Water Framework Directive
- have a positive impact on flood protection
- benefit various fish and bird species - including the common sandpiper, kingfisher, sand martin and European bullhead - thanks to planned river restoration measures, such as the creation of gravel banks and bank erosion
- in the long term, enable self-sustaining populations of the Danube salmon, which was recently detected again in the Enns, alongside other rheophilic fish such as the grayling and the common nase
- develop 7.6 hectares (ha) of extensive meadows with shrubs and hedges will create suitable breeding habitats for the red-backed shrike and other open landscape birds
RESULTS
The expected results of the WeNatureEnns project are:
- creation of approximately 35 ha of new riparian areas available for natural development and protected by law
- removal of 18.4km of embankments along the River Enns allowing natural hydro-morphological dynamics
- increase of the riparian buffer zones over 18.4km of the river by transformation of more than 47.6 ha of heavily altered river habitats, 34.6 ha of agricultural land and 3.3 ha of infrastructure into a natural river-floodplain corridor
- creation of more than 200 engineered log jams, chevrons and large woody debris to provide shelter and enhance morphological dynamics
- dumping of gravel to improve the groundwater table, increase structural diversity and foster morphological dynamics
- improvement in the connectivity of the River Enns to 6 tributaries to improve fish passage between the Enns and its tributaries
- improvement in the habitat structure in 5 tributaries (3.3km in total) as spawning and wintering grounds for fish
- planting of 4.5km of hedges as breeding sites for birds
- planting of approximately 2 500 trees
- seeding of 7.6 ha low land hay meadows
- establishing 6 amphibian ponds of 250 m² each
- construction of 11 reptile habitats (stones piles)
- support of at least 20 new breeding pairs of little ringed plover, common sandpiper and kingfisher, representing a 10- to 20-fold increase in density
- establishment of at least 1 breeding colony of the sand martin in the project area with about 60 breeding holes
- 20 wintering great grey shrikes
- 30 breeding pairs of the red-backed shrike
- colonisation of new sites and population increase of the Danube salmon and the European bullhead