Sigalda Hydroelectric Station
Sigalda is Landsvirkjun’s second major hydro plant. Construction began in 1973 and the station’s three 50 MW turbines went on stream in 1977-78. The river Tungnaá is dammed at the top of the chasm above Sigalda hill to form a 14 km2 reservoir, Krókslón. The Sigalda dam is 925 m long, an earth-fill dam with asphalt covering on the reservoir side. Water from the reservoir is channelled along a 1 km headrace canal through the hill to the intake point on the western edge of Sigalda. From there, three 216 m penstocks, 4.3 in diameter, lead to the powerhouse which is located north of the old river course and partially underground inside Sigalda. The harnessed head is 74 m. A tailrace canal leads from the powerhouse to the Hrauneyjafoss reservoir. The Sigalda Station is linked to the national grid by 220 kV transmission lines to the Sultartangi, Hrauneyjafoss and Vatnsfell stations, and a 132 kV line to the southeast. Personnel at Hrauneyjafoss Station service Sigalda.