NorskHydro has begun blasting new feeder tunnels from the two lakes Holsbruvatn and Rausdøla to the old hydropower station at Tyin in Norway.
The blasting marks the start of the Holsbru project, which will increase the Hydro's annual power production in Sogn by 84GWh.
Because of the new tunnels to the power station at Tyin, the firm will be able to utilise water resources that have not previously been used.
Once production resumes at two of the generators in the old station, production will increase by 84GWh, with the total power production from Tyin exceeding 1,600GWh.
Hydro plans to invest over NOK 200m ($31.8m) on the project.