News

After approval of the Kühtai expansion project by the competent authorities, the project is now picking up speed: As a result of  the tendering procedure, the project has been awarded to the domestic Swietelsky-Jäger-Bodner consortium. The contract volume is € 425 mio. TIWAG will invest close to one billion Euros in expanding and op-timising the existing installation.

Creating jobs and added value

"Especially in times like these, what is currently the biggest and most important TIWAG expansion project is an important engine of growth for the domestic construction industry. Main construction work will start in Kühtai as early as next spring and will give employment to 500 people during the five years of construction. It is also very good news that over the next five years, TIWAG is planning to invest a total of 1.2  billion Euros, an important signal for Tyrol as an industry location", says Günther Platter, Governor of Tyrol and representative of the TIWAG owners.

Preparations are now ongoing to set up the large building site in the Längental valley. "The entire population of amphibians has already been relocated from the affected areas to the newly created biotopes. Valuable topsoil has been removed and stored for subsequent recultivation", points out Johann Herdina as head of construction. If everything goes according to plan, heavy machinery will be deployed in Kühtai in April 2021 and construction will be completed in late 2026.

Overview of main construction works

The project basically comprises the new Kühtai reservoir in the rear Längental valley, the construction of an underground pumped storage station named "Kühtai 2", and the adduction of several streams from the Stubaital and Ötztal valleys:

• Kühtai reservoir: 6.7 mio m3 of  bulk volume, dam with a crest length of 510 m and a height of 113 m, 2 km tunnel in cyclic drive with a gradient  of up to 80%
• Kühtai 2 powerhouse: 80,000 m3 of excavated material, 4 km tunnel in cyclic drive, all concrete works for the expansion of the  powerhouse
• Adduction: 25 km tunnel in continuous drive, 2 km in cyclic drive, construction of water intakes for the Winnebach and Fernaubach streams

The expansion project will increase the storage capacity of the existing installation by about 50%, and the additional water will increase electricity generation by 216 mio kWh per year. "This will have an immediate impact on strengthening the energy autonomy and supply security in Tyrol. Only storage plants of this kind can bring about the successful  energy transition in Tyrol, in Austria and even in Europe", states Erich Entstrasser, Chairman of the Board of TIWAG.

As one of many ecological measures accompanying the Kühtai expansion project, construction work at the Brunai weir along the municipal border between Haiming and Sautens has started this week. TIWAG is spending about three million Euros on providing unhindered and safe passage for fish and other aquatic organisms in the Ötztaler Ache river.

"This measure will ensure fish passage in future, opening up an about nine-kilometer section of the Ötztaler Ache as an aquatic habitat while closing the link to the River Inn", emphasises TIWAG Director of the Board Johann Herdina. "Not only organisms living in and on the river will benefit but so will water sports because potential haz-ards at the weir will be removed".

The existing weir dates back to the 1950s and has since been used to irrigate agricultural land, such as the orchards in Haiming, with water taken from the Ötztaler Ache. However, the  two-meter drop was an insurmountable obstacle for fish. There was also dangerous backflow, which is why this section of the river was closed to water sports enthusiasts.

"Removing these man-made hazards is an enormous benefit for the booming rafting and kayaking scene in the Ötztal valley" says Marcel Pachler, President of the Tyrolean Rafting Association. Mayor Manfred Köll from Sautens and his counterpart Josef Leitner from Haiming are full of praise for TIWAG's collaborative effort that also ensures  irrigation of the horticultural land.

The work is undertaken in the current low-water period and is to be completed by April 2021. The river bed will be raised downstream and a ramp about 300 meters in length with a two-percent  gradient will be built. Large armour-stones will secure the embankments to give them a near-natural appearance.

Construction work for the new surge compensation reservoir of the Kühtai pumped storage station is progressing according to plan. The reservoir, located in the municipality of Stams, has a capacity of 300,000 m3 and is designed to sustainably upgrade the River Inn as a natural habitat. "By introducing the power station outflow into the compensation basin, surge is reduced before the water is fed into the River Inn", says TIWAG Director of the  Board Johann Herdina during a site visit. "This is an important contribution of TIWAG to the long-term 'greening' of the River Inn". Construction costs for the reservoir are about 19 mio Euros, completion is  planned for April 2023.

The excavators are not operating at present as work is not allowed during the bird breeding period (15 Apr to 31 Jul). The topsoil of the reservoir with a surface area of 100,000 m2 has been removed and the earth works partly completed. The concrete structure that connects the reservoir to the power station outlet is complete, as are the laying platform for subsoil sealing and the rubber dam. Excavation will continue in autumn..

Major revision in Kühtai is nearing completion

The mandatory large-scale revision of the Kühtai power station infrastructure is also making excellent progress. Inspection and refurbishment work on the two reservoirs was completed two weeks earlier than planned. Filling of the Längental reservoir started at the end of May. The Silz power station is fully operative again, and  work on the Finstertail reservoir is nearly completed. From mid-August the upper stage will resume pump and turbine operation

Total costs amount to about 60 mio Euros. "We made  use of the temporary shutdown to implement new ways of sustainable sediment management at the Längental reservoir. As a result, the reservoir will not have to be drained completely in future for revision purposes", emphasises Johann Herdina.

Preliminary work for power station expansion

Main construction work for the expansion of the Sellrain-Silz group of power stations is planned to start in spring 2021 but preparatory work has been ongoing since autumn 2019: new biotopes for frogs and mountain newts were created in Kühtai, and anthills were removed to safe locations away from the future building site. Earth works can start only after these accompanying measures have been completed. The topsoil also has to be removed first and stored for subsequent recultivation.

These preparatory measures are part of the project approval and are carried out under the supervision of the na-ture conservation authorities. The bulk of  the contract volume for the compensation reservoir in Stams and the preliminary work in Kühtai goes to local businesses from the upper Inn valley. This translates into 29 mio Euros for regional  companies in 2020 alone.

Further information:

TIWAG-Tiroler Wasserkraft AG

DI Johann Herdina

Vorstandsdirektor

T 050607 – 21011

The final ruling of the Austrian Administrative Court has removed all obstacles to the expansion of the Kühtai group of power stations that is so important for the energy transition. "During the eleven-year procedure, our project has been reviewed at multiple levels. The recent ruling ultimately completes the extensive environmental compatibility review necessary for the construction and operation of the Kühtai expansion project, as confirmed by all supreme courts", says TIWAG Chairman of the Board Eric Entstrasser.

"Besides electricity conservation and the promotion of other eco-friendly technologies, the expansion of hydropower is a prerequisite for Tyrol's energy autonomy", says Günther Platter, Governor of Tyrol and representative of TIWAG owners, and shows himself pleased with the news from the Vienna courts. "In challenging economic times, this project is all the more important as a driver of Tyrol's construction industry. Our Tyrolean energy pro-vider is investing almost one  billion Euros in expanding the existing installation".

The Kühtai expansion project provides for an additional reservoir with a capacity of 31 mio m3, as well as a pumped storage station for a second upper stage to increase the total storage capacity by about 50%. The offi-cial start of construction is planned for spring 2021. "Planning is mostly complete. Preparatory building work in Längental started already in autumn 2019", explains TIWAG Head of Construction Johann Herdina.