Upper Nepean Catchment

My part of the catchment

The Upper Nepean catchment covers almost 900 square kilometres of mostly pristine bushland on the Illawarra Plateau south of Sydney. Its tall forests, swamps and rainforests are home to many rare and threatened species, including the white waratah.

The catchment lies at the southern end of the Illawarra Plateau, which stretches from Robertson north to Heathcote National Park, and is bordered by the Illawarra escarpment in the east, Campbelltown in the north-west and the villages of Bargo and Yerrinbool in the south-west.

Most of the catchment is covered by the Metropolitan Special Area. Protected from most human activities for over 130 years, the area is a haven for the spotted-tail quoll, giant burrowing frog, flame robin, swift parrot and sooty owl.

The catchment is also the home to the white waratah. Like the Wollemi Pine, the exact location of the white waratah, discovered in the 1960s, has been kept secret for its protection. Most of all white waratahs available today have their ancestor in this one plant.

There are no urban areas in the catchment, but Bargo, Wilton and Appin lie along the catchment's north-western boundary and Robertson, Kangaloon, Glenquarry and Braemar lie on the southern edge.

Land in the catchment is mostly owned by WaterNSW and the National Parks & Wildlife Service which manages Dharawal National Park.  A small area of privately-owned land, mainly used for grazing, is located in the southern part of the catchment. Most of the catchment is a Special Area which protects water quality by providing buffer zones of pristine bushland.

It is one of the highest rainfall zones on the mid-NSW coast, and the area's rivers, located in narrow gorges, provided ideal dam sites.

Your water supply

As early as 1888, two weirs built on the Cataract and Nepean rivers captured the high rainfall in this catchment as part of Sydney's water supply. The successive building of Cataract, Cordeaux, Avon and Nepean dams between 1907 and 1935 greatly increased the capacity of the Upper Nepean Scheme.

Today, the catchment also supplies water to nearby communities, and the Illawarra and Macarthur areas. Nepean Dam supplies Bargo, Thirlmere, Picton and The Oaks, as well as the Macarthur and Prospect water filtration plants. Cataract and Cordeaux dams supply water to the Camden, Campbelltown and Wollondilly council areas via the Macarthur water filtration plant. Avon Dam supplies the Illawarra region.

In the area

Avon Dam

Avon is one of four dams that make up the Upper Nepean water supply scheme south of Sydney on the Illawarra Plateau.

Cataract Dam

Cataract Dam is one of the oldest and most picturesque dams in Sydney. At the time of its construction from 1902 to 1907, Cataract Dam was the biggest engineering project in Australia and the fourth biggest in the world.

Cordeaux Dam

Cordeaux is one of four dams that make up the Upper Nepean water supply scheme south of Sydney on the Illawarra Plateau. Remarkable for its Egyptian inspired architecture, a visit to Cordeaux Dam is like stepping back in time.

Nepean Dam

Nepean Dam was the last and smallest of the four dams constructed to collect water from the Illawarra Plateau south of Sydney.

Click on your local council area to find out how it sits in the Upper Nepean catchment

Living in the area

Developers & Council

Learn about the best approaches for managing stormwater during and after construction - for a home site or large development.

Developers & Council

Find out how you can look after your property at the same time as caring for your local catchment and waterways.

Developers & Council

Get practical tips on onsite wastewater systems - whether you have just moved to a property or are installing a new system.

Land management in action

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The multi-generational farming family

Man in paddock
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The hobby farmer

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The farm manager

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Monday 18 October
2,426,169 ML
2,581,850 ML
9,030 ML
1,290 ML
3,065 ML
Monday 18 October