Following the closure of the Mount Lyell Mining and Railway Company, in 1985 the control of the dam, lake, and power station was transferred to Hydro Tasmania.

The Bastion, at 1,107 metres (3,632 ft), which is a steep cliff face that is immediately west of Lake Magdala and north of Mount Geikie, together with Farquhar Lookout, with an elevation of 935 metres (3,068 ft), define a rough line of the northern part of the 21-square-kilometre (8.1 sq mi) catchment area.

The vesting of the catchment with the current operator of the hydro electric power station, makes the two feeder parts of the catchment specific Hydro land in contrast to the surrounding landscape which is either in the Tyndall Regional Reserve or the Lake Beatrice Conservation Area.

While the mine has since closed, the purpose of Lake Margaret to generate power remains unchanged.

Between 1918 and 1930 the Mount Lyell Mining and Railway Company commissioned seven conventional Pelton turbine generators with a capacity of 8.3 megawatts (11,100 hp) at the Upper Lake Margaret Power Station.

Water travels from Lake Margaret through a woodstave 2.2-kilometre (1.4 mi) pipeline to the power station.