The Mersey Forth Catchment

The Mersey Forth Power Development was started in 1963 and completed in 1973. It uses the water from four rivers in the area, the Fisher, Mersey, Wilmot and Forth, and comprises seven power stations, three major tunnels and associated penstocks, canals and flumes. The development is spread over an area of 2070 square kilometres and uses water that begins its journey at an altitude of 1120 metres on the Great Western Tiers and falls to sea level below the seventh power station.

Lake Mackenzie

Two dams, Rowallan and Parangana, were built on the upper reaches of the Mersey River. Lake Rowallan is the main storage for the development. Water from the lake flows through the small (10.5 MW) Rowallan Power Station and down into Lake Parangana.

Lake Parangana also receives water from high up on the Great Western Tiers. A dam on the Fisher River raised the level of Lake Mackenzie. Water from the lake flows by flume, canal, tunnel and pipeline to the Fisher Power Station. Its journey involves a drop of some 650 metres. The station has a capacity of 43.2 MW and discharges its water into Lake Parangana.

Devils Gate Dam spilling

The water in Lake Parangana is transferred in a westerly direction from the valley of the Mersey River into the Forth River via a 6.8 kilometre tunnel. After it leaves the tunnel it passes down through penstocks and the 51 MW capacity Lemonthyme Power Station. A dam on the Wilmot River diverts water in an easterly direction into the valley of the Forth River.

The water passes via tunnel and penstock through the 30.6 MW capacity Wilmot Power Station on the edge of Lake Cethana.

The combined flows of the Mersey, Fisher, Wilmot and Forth Rivers are then used for power generation at three further power stations on the Forth River situated at the foot of dams at Cethana, Devils Gate and Paloona.
The Devils Gate Dam is a spectacular concrete arch structure and forms Lake Barrington, renowned as an international-standard rowing course and the venue for the 1990 World Rowing Championships.

The combined generating capacity of the seven power stations is 308.3 MW and they contribute about 15.8 percent of the State's energy needs.

Paloona Dam and Power Station