The present lake was formed during the building of the Sjona hydroelectric power station during the early 1970s, when the original Holmvatnet was dammed and flowed together with the lake Nedre Fagervollvatnet further upstream. The reservoir has an area of 4.84-square-kilometre (1.87 sq mi) and the elevation is regulated between 275 and 254.3 metres (902 and 834 ft) above sea level.[3]