The Salmon Connect project aims to restore ecological connectivity in the Radlbach by removing two barriers that currently disconnect the river from the Lieser, impacting biodiversity and natural processes.
The Radlgraben is considered the deepest valley in Europe. This spectacular landscape is shaped by the Radlbach, a small alpine river with a “very good” ecological status. It hosts one of the last populations of the autochthonous Salmo trutta (“Urforelle”), supports a high breeding density of riparian bird species such as Cinclus cinclus, and provides habitat for a unique population of Trentepohlia sp., a filamentous green algae that colours the banks in striking orange and red.
A disastrous flood in 1967 led to the construction of two barriers to manage sediment transport in the lower section. These now disconnect the Radlbach from the Lieser river, disrupting natural dynamics and causing a significant loss of fish biomass.
| Project status | Live |
|---|---|
| Project type | Dam removal: pre-demolition |
| Country | Austria |
| River | Radlbach |
| Focal species | Salmo trutta, Cottus gobio, Cinclus cinclus, Lutra lutra, Alnus incana, Trentepohlia sp. |
| Organisation | WWF Austria |
| Website | wwf.at |
By removing both dams, Salmon Connect aims to restore the ecological connectivity of the entire Radlbach river system and reconnect it with the Lieser river. Both rivers are classified with a “very good” ecological status, and this effort will restore a total of 57 km of river habitat (14.5 km upstream).
The de-damming action is also a strategic step towards long-term conservation of the Radlbach. Currently, neither the river nor its catchment area benefits from any conservation designation. According to GIS analyses, the Radlgraben catchment area features extremely low levels of human infrastructure, which is exceptional in Carinthia, Austria, and even across the Alps. This area serves as a vital ecological corridor between the Hohe Tauern National Park and the Nockberge Biosphere Park.
Based on field investigations and analyses of technical maps and data, the main focus of this project is the technical planning for the removal of these barriers. The dam removal requires permissions from the competent authorities which will also be obtained within the project.
A video clip will showcase the outstanding beauty of the Radlbach and promote long-term conservation for the river and its catchment area. This will be supported through study visits and stakeholder workshops.
The restoration and conservation concept should help to develop the Radlbach towards a Free Flowing River (according to Article 9 of the Nature Restoration Regulation), resulting in funding opportunities for the follow-up demolition of both dams. As a consequence, restored connectivity should qualify also the Lieser river to meet criteria for Free Flowing River even on a “large scale assessment”.
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