Marking 100 years protecting Sydney’s water

The Metropolitan Catchment Area was proclaimed in 1923 to protect the water that flowed into the Nepean, Avon, Cordeaux and Cataract rivers above Pheasants Nest and Broughton Pass weirs that at the time supplied most of Sydney’s water.

Today the Greater Sydney catchment – managed by WaterNSW - covers 16,000sq/km from north of Lithgow and south to beyond Braidwood. It stretches from Crookwell on its the western fringe to near the coast adjoining Wollongong.

Catchment protection involves minimising potentially adverse factors so that the run-off from rain that falls in the catchment and makes its way to dam storages via river and creeks, is as clean and plentiful as possible, even before it is treated for consumption.

These measures range from regulating human activity like industry, farming and urban development, through to enhancing the natural environment, and advising governments on water-friendly policy based on research and scientific expertise.

WaterNSW manages the Greater Sydney catchment to reduce risks to water quality, prevent environmental degradation, as well as conserving cultural values, according to WaterNSW executive manager strategy and performance, Fiona Smith.

“WaterNSW is proud to jointly manage the areas that protect Greater Sydney’s drinking water catchments, in partnership with the NSW National Parks and Wildlife Service, and our neighbours and stakeholders,” she said.

The catchment protection approach includes areas designated “special areas” that are recognised as particularly significant and are off-limits to all but essential human access.

Special areas cover 364,778 hectares of land that surrounds and protects water supply storages for the people of Sydney and the Illawarra, Blue Mountains, Southern Highlands, Goulburn and Shoalhaven regions.

“The special areas are part of a multi-barrier approach to address risks to water quality throughout the whole of the water supply chain, that starts with the raw, untreated collected from rainfall and river flow in the catchment,” Ms Smith said.

“The multi-barrier approach recognises that while each individual barrier may not be able to completely remove or prevent contamination all of the time, they collectively provide greater assurance that the water supply will always be safe,” she said.

Background

The Metropolitan Catchment Area was proclaimed in 1923 to protect the water that flowed into the Nepean, Avon, Cordeaux and Cataract rivers above Pheasants Nest and Broughton Pass weirs that at the time supplied most of Sydney’s water.

Covering 90,239 hectares on the Woronora Plateau south of Sydney, and later re-named the Metropolitan Special Area, it is believed to be one of the longest-standing drinking water catchment protection areas in Australia.

More Special Areas followed the successful creation of the Metropolitan Special Area in 1923 (amended 1933): Woronora Special Area (established 1941), Warragamba (1942), Shoalhaven (1970), Fitzroy Falls (1973), Wingecarribee (1973), Blue Mountains (Blackheath, Katoomba, Woodford, 1991), and Prospect (2008).

The Metropolitan Special Area was designed to protect the water quality of the Upper Nepean scheme, a network of dams and pipelines built in the late 1800s to solve Sydney’s water supply problems by capturing water from where it rained frequently and heavily south of Sydney, and transferring that water to Sydney.

It was the first time in Australia that water was collected well away from a city, transported by canals and pipelines, and stored in a major dam (Prospect Reservoir).

A Royal Commission after the Federation Drought of 1901-02 expanded the Upper Nepean system by building four new dams: Cataract (completed 1907), Cordeaux (1926), Avon (1928) and Nepean (1935).

Throughout the past 100 years the water that flows into those dams and weirs has been protected by the native bushland and upland swamps of the Metropolitan Special Area. Today, it is a haven for native flora and fauna, including many threatened or endangered species.