Hieflau Power Plant

At the gates of the Gesäuse National Park on the river Enns in the municipality of Hieflau lies the most powerful VERBUND hydropower plant in Styria.

Man in the kitchen

83.508 households 

supplies the Hieflau power plant

Conscious of the environment

278.953 avoided
tonnes of CO2*


Efficiency increase

Comprehensive renewal of the Hieflau power plant completed in 2013

In the Hieflau powerhouse, there are three machine units with vertical shafts and an installed capacity of altogether 63,000 kW. Every machine unit is made up of one Francis spiral turbine and one three-phase synchronous motor. The powerhouse, which is located in the same power plant of Hieflau-Erzbach, also uses a gradient level of the Erzbach for generating energy and for its own power supply. 

Wag Reservoir

The Wag reservoir, a reservoir created by dams, has a top water level of 565.5 m. The useful capacity is 1.66 million m3. From the surge tank and from the reservoir there are three 260 m long steel pressure pipes leading to the Hieflau powerhouse at the foot of the Wag plateau. 

At the Hieflau power plant, a big stack of ecological accompanying measures were implemented. In the immediate vicinity of the Gesäuse national park, four times more water will be fed into the river Enns after the rebuilding, so that even a reintroduction of the Danube salmon will become a possibility. In the course of the expansion measures, the Gstatterboden weir was equipped with a modern fish ladder. 

Image from the Location

Owner VERBUND Hydro Power GmbH
Operator VERBUND Hydro Power GmbH
Commissioning 1956
Type Storage power plant
Country Austria
Region Styria
Waters Enns
Output 63 MW
Annual output 369,653 MWh
Turbine Francis
Connectivity Fish bypass
Environmental protection at VERBUND

At the Hieflau power plant, a wide range of supporting ecological measures was implemented. In the immediate vicinity of the Gesäuse National Park, four times more water has been released into the Enns since the conversion, so that even re-population with the Danube salmon is conceivable. 
As part of the expansion measures, the Gstatterboden weir was equipped with a modern fish bypass.

Responsible treatment of the environment
Fish bypass

The Hieflau power plant consists of the Gstatterboden weir system, the Wag daily storage facility and the Hieflau powerhouse.

Turbines and generators:
Three Francis turbines with vertical shafts and sheet metal spirals have a nominal output of 22,000 kW at a nominal drop height of 85 metres. The directly coupled 25,000 kVA three-phase synchronous generators supply electricity with a nominal voltage of 10.5 kV.

Transformers: The generated energy is raised to 110 kV via three 25,000 kVA machine transformers transmitted via a loop of the Hessenberg-Ernsthofen line. 

The Wag daily storage tank holds 1,650 million litres of water, which corresponds to an energy content of 330,000 kilowatt hours.

Hydro consulting from VERBUND