Fitzroy Falls Reservoir

Facts and History

Located about 140 kilometres south of Sydney, Fitzroy Falls Reservoir is on Yarrunga Creek upstream of Fitzroy Falls and about 20 kilometres south-east of Bowral. It consists of four separate earth and rockfill embankments, completed in 1974 as part of the Shoalhaven Scheme.

Why the Shoalhaven Scheme was built

Plans for a water supply in the Shoalhaven first arose at the end of World War I, but it was not until 1968 that the Water Board consulted the Snowy Mountains Hydro-Electric Authority about the longer-term water needs of Sydney and the south coast. There was concern that Warragamba Dam, which had opened only eight years earlier, might not be enough to meet Sydney's water supply needs by the mid-1970s.

The advice was to proceed with the Shoalhaven Scheme. Construction of Tallowa Dam began in 1971 and was completed in 1976. Construction also commenced on reservoirs on the coastal range above Fitzroy Falls, and on the Upper Wingecarribee River. Fitzroy Falls and Wingecarribee reservoirs were completed in 1974.

Water from Tallowa Dam, and Fitzroy Falls and Wingecarribee reservoirs, is now used to supply local communities and supplement Sydney and Illawarra water supplies. Power generation involves regular exchange of stored waters between Lake Yarrunga, Bendeela Pondage and Fitzroy Falls Reservoir.

How the Shoalhaven Scheme works

The Shoalhaven Scheme is unique in Sydney's water supply, designed as a dual-purpose water transfer and hydro-electric power generation scheme.

Water pumped from the Shoalhaven Scheme is mostly collected from the Tallowa Dam catchment of 5,750 square kilometres. Wingecarribee and Fitzroy Falls reservoirs have relatively small catchment areas totalling only 70 square kilometres.

Water from the Shoalhaven Scheme provides water to the local Southern Highlands and Goulburn communities. It can also be fed into Warragamba Dam and the Upper Nepean dams to top-up the Sydney and Illawarra water supplies.

From Wingecarribee Reservoir, water can be released into the Wingecarribee River, which flows into the Wollondilly River and Lake Burragorang to feed the main Sydney supply system via Warragamba Dam. Water can also be released from Wingecarribee Reservoir via canals and pipelines (collectively known as Glenquarry Cut) into the Nepean River which flows into Nepean Dam. From there, it can be transferred to Sydney via the Upper Canal or to the Illawarra region via the Nepean-Avon tunnel to Avon Dam.

As well as supplementing water supply, the Shoalhaven Scheme also supplies water to local communities. Wingecarribee Reservoir supplies Bowral and Mittagong via Wingecarribee Shire Council's water filtration plant next to the reservoir. Goulburn can also be supplied with water from Wingecarribee Reservoir in drought times. Kangaroo Valley township is supplied from Shoalhaven City Council's treatment plant, which draws water from Bendeela Pondage. Water is also released from Tallowa Dam into the Shoalhaven River so that Shoalhaven City Council can extract water from the river to supply Nowra.

The Shoalhaven Scheme hydro-electric power generation involves pumping water up the system between Lake Yarrunga and Fitzroy Falls Reservoir using off-peak electricity. Some of that water is then released back down the system to generate electricity during periods of peak demand. The power is fed into the state-wide transmission grid through the Canberra-Dapto transmission line.