The Wiesberg power plant, which is owned by the Austrian chemical company Donau Chemie AG, supplies the Landeck power plant with electricity for carbide production. It was considerably damaged by the flood disaster in August 2005. Among other things, the Trisanna and Rosanna water intakes, as well as the headrace system “Small Rosanna Tunnel” and the “Rosanna Pressure Pipeline (DN1500)” were almost completely destroyed. It was not possible to reconstruct this headrace tunnel, as the route lies in the still active slide area of the Zintl forest.

The Trisanna and Rosanna water intakes were already rebuilt in winter 2005 / 2006. However, the second Rosanna headrace system, which has been preserved, could only discharge a part of the amount of water allowed by official notification. For this reason, the widening of the “Rosanna tunnel” was started in 2005 / 2006 but not completed. The remaining approx. 736 m of tunnel still to be widened were executed in 2019 / 2020.

In the future construction lot, the “Trisanna surge tank”, in which the entire water volume of the Trisanna and Rosanna water intakes is combined, will be extended; and the existing DN2100 pressure and distribution pipeline will be replaced by a DN2600 welded steel pipeline (approx. 229 m long).

The BERNARD Gruppe has been commissioned with tender and execution design.

Wolfgang Holzer, BERNARD Gruppe