The construction involves driving more than 22km of pressure tunnel and is the biggest and most significant of three contracts for the hydroelectric power station on the River Inn. The tunnel will be completed in mid-2018.
Hochtief Infrastructure general manager Wilfried Rammler said: "We are happy to have won another large-scale contract in the Austrian market. This underscores our competence in the construction of sustainable energy infrastructure in Europe."
The 6.5m-diameter pressure tunnel will run underground from the reservoir in Ovella to the powerhouse in Prutz. Hochtief will drive the pressure tunnel with two hard rock double-shield tunnel boring machines. The excavation material will be stored near the construction site in order to keep site traffic to a minimum.
The tunnel will be lined with prefabricated concrete lining segments, which will be produced locally.
Once complete, water will be channelled through the tunnel to the powerhouse in Prutz and used to generate power for more than 100,000 households.