With the exception of flood events, the water level will lie at the level of these intake thresholds. There will not be any active control of the water level as takes place in larger reservoirs, but a flood control in which the water varies naturally within the specified regulation height in flood situations.
A 450 metre long water tunnel was drilled to transfer the inflow from Longatjørna to Hefteholstjørna. This was followed by partly drilling and partly blasting a tunnel extending 2,050 metres from Hefteholstjørna to Lyngsvatn. In addition a 1,050 metre long tunnel was blasted from Grønakråtjørna to Lyngsvatn.
There is no need for further infrastructure or technical installations for the transfer. The project will be built without a road.
Impact assessments for the transfer have been conducted within the specialised fields of hydrology, fishing, natural environment, cultural heritage, landscape, outdoor recreation, society and natural resources. According to the impact assessments the overall impact of the initiative is insignificant to slightly negative.
The project is calculated to cost NOK 87.3 million.