Since the beginning of September, water from the Unterer Tuxbach has travelled along a new, 8.6 km-long underground tunnel to the existing Stillup reservoir. There, it is used multiple times by a new small-scale hydropower plant and subsequently by the Mayrhofen power plant to generate hydropower.
Project folder Unterer Tuxbach (German only)
| Owner | VERBUND Hydro Power GmbH |
|---|---|
| Operator | VERBUND Hydro Power GmbH |
| Type | Run-of-river power plant |
| Country | Austria |
| Region | Tyrol |
| Output | 02 MW |
| Annual output | 74,000 MWh |
A central element of the Tuxbach crossing is an 8.6 kilometre-long tunnel connection between the lower Tuxbach and Stillupp reservoir. The total construction time for the project, which commenced at the beginning of 2017, is estimated at 3 years.
At the end of the crossing, at the confluence with the reservoir, a green electricity power plant with a power output of around 1.7 MW will be constructed. The unique combination of the new crossing and the connection with the existing power plant at Mayrhofen and the new Stillupp small power plant will facilitate the generation of around 45 GWh of hydroelectricity per year.
In the existing powerhouse at Bösdornau, only one machine set will now be operated with the water of the Zemmbach, in order to cover the power plants’ own needs and to ensure cold-start capability in the event of large-scale power failures. In this way, it remains possible to use these plants for step-by-step restoration of the power supply across the country following an outage. The residual use of the power plant at Bösdornau also ensures that the industrially historic and attractive power plant constructed between 1928 and 1930 remains part of the history of hydropower in the Tyrol and at VERBUND.
The existing Tuxbach power plant in the municipality of Finkenberg in Zillertal is to be abandoned. The removal of the Großdornau basin, which is part of the power plant, has been negotiated with the municipality and will create open areas for use as it sees fit. The pipelines that currently run above ground to the Bösdornau power plant will be laid underground in the Großdornau area.
The implementation of the project was examined for its ecological impact and the preservation of natural conditions, and appropriate measures were taken into account in the construction plan.
The central element of the Lower Tuxbach project, which is being implemented in the Zillertal Valley in collaboration with Stadtwerken Schwaz (German only), is an 8.6 km long connecting tunnel between the lower Tuxbach stream and the Stillup reservoir. Over the course of the last months, by means of blasting, the conditions were created for use of a tunnel boring machine. Its use was launched with a little ceremony in front of the tunnel portal, to express the hope of successful and especially of accident-free construction. The tunnel boring machine will first advance the tunnel starting from Karlsbach in the direction of Tuxbach. Then the machine will be withdrawn from the mountain and will create the connection between Karlsteg and the Stillup reservoir.
