HEPP Finsing

Lot 2 Headrace Structures


TIWAG-Tiroler Wasserkraft AG


BeMo Tunnelling GmbH (BeMo)

Project location

Finsing, Uderns and Fügenberg, Zillertal, Austria

Start of construction


End of construction


Project total value

7.5 million €


Massive rock, Wildschönau slate, soil

Technical Data

Construction of headrace structures (adaption of existing headrace gallery, new connection gallery and surge chamber shaft, inclined shaft and penstock)
The two hydropower plants which were built in the 1920s have been combined to a single step hydropower plant. The standard capacity (SC) of the new hydropower plant at medium water level is 20.91 GWh per year.
Tunnel length: ca. 900 m (inclined shaft and penstock)
Penstock: 635 m
Surge Chamber Shaft: 44.25 m (ø 6 – 8.8m)
Inclined Shaft: 215 m (ø 1.4 m, 50° inclined, raiseboring)
Connection Gallery (Shaft floor – existing water gallery): 53 m (5.9 m²)
Excavation: Drill and blast (galleries and cavern), raiseboring (inclined shaft), shaft sinking (surge chamber shaft)
Design: NATM, shotcrete lining using wire mesh, steel fibers were used instead of wire mesh in geologically suitable classes, in-situ concrete lining, additionally reinforced shotcrete lining instead of secondary lining in geologically sensitive upper area of the surge chamber shaft (proposed by BeMo)
Concreting of wear-resistant layer steel pipes and penstock using the tremie method
Hydraulic steel structures: steel pipes (each 12-m-long, DN 1000) laid top-down in the inclined shaft, coupled to the lower manifold