Construction work on the new plant on the Missouri river, near Great Falls, is scheduled to start in 2010. The work will also eventually see the removal of the current, 35MW plant, which has eight units.

The new plant, which has a fish-friendly design, is scheduled to be completed and operational in 2012.

PPL Montana said the redevelopment of the facility is part of its Project 2188 licence with FERC.

The existing facility, classed as run-of-river, was built in 1910 and includes a 8.8m high dam