TIWAG-Tiroler Wasserkraft AG has broken through on a 25.6km diversion tunnel for the Kühtai 2 pumped storage hydro power project in Austria’s Stubai Valley.
The TBM was launched in April 2022 and made its final breakthrough at the Wilden Grube near the Daunkogelfernerbach water intake. During four years of tunnelling it set a maximum daily advance of 63m, a monthly record of 1km and installed 18,818 segments.
The TBM was named, Alesja – an acronym of the first names of some of the employees involved in the construction: Aida, Lisi, Elisa, Sabine, Jacky and Anna.
The 4.2m-diameter tunnel will provide a pipeline connection to a new reservoir in Kühtai.
The project has also included the construction of a 4.5m-diameter headrace tunnel and the power station in an underground rock cavern.
Work on in the Kühtai project continues, with the 113m-high dam nearing completion. Approximately 6.9 million m³ of material excavated from the reservoir and underground works have been used in the dam construction. The dam is around 500m wide and has a volume of 6.9 million m³.
Reservoir filling will commence this summer, and a dam “crowning” ceremony will be held in July.
The hydro power plant is scheduled to be operational in 2027.
