Sigalda Power Station

Sigalda Power Station is located south of Þórisvatn and is directly connected to Hrauneyjafoss Power Station through a short tailrace canal.

The Tungnaá River is dammed above Sigalda, forming Krókslón, a 14 km² reservoir. Water is conveyed from the reservoir through a 1 km intake canal to the powerhouse. Three pressure shafts carry the water to the turbines, which utilise a head of 74 metres.

After passing through the station, the water is discharged into Hrauneyjalón reservoir and continues through the hydropower system downstream.

Sigöldugljúfur is a former river channel of the Tungnaá River. Before Sigalda Power Station was commissioned, the river flowed through the canyon. Today, Sigöldugljúfur is known for its turquoise water, numerous small waterfalls and rich vegetation, making it one of the most distinctive natural attractions in the area.

Sigöldugljúfur remains part of the Sigalda hydropower system. Water levels can rise without warning when water is released through the dam or spillway, and visitors are therefore advised to stay on designated viewing areas.

The Þjórsá and Tungnaá area is home to seven of Landsvirkjun’s hydropower stations: Búðarháls, Búrfell, Búrfell II, Hrauneyjafoss, Sigalda, Sultartangi and Vatnsfell. The area also includes Vaðalda Wind Farm, Iceland’s first wind power plant, as well as Hafið, a wind energy test site with two experimental turbines.

At the heart of the system is Þórisvatn, Iceland’s largest natural lake and the region’s main reservoir. Water collected in the Kvíslaveita diversion system and Hágöngulón flows through Þórisvatn before being used by power stations farther downstream.

The Þórisvatn reservoir system was developed between 1970 and 1972 as part of the expansion of hydropower generation in the area. Its reservoirs, dams, canals and control structures make it possible to store water, regulate flows and optimise energy production throughout the year.

Construction of the Kvíslaveita diversion system began in 1980 and was completed in 1997. The system collects water from tributaries and the upper reaches of the Þjórsá River and diverts it to Þórisvatn.

Hágöngulón was developed between 1997 and 1999 and covers an area of 37 km². It increases the utilisation of water resources in the Kaldakvísl catchment by storing water during the summer months.

Together, Þórisvatn, Kvíslaveita, Hágöngulón and a number of smaller reservoirs form the backbone of the hydropower system in the Þjórsá and Tungnaá area.