Murray

Rivers. There are three main river systems within the Sydney region: Hawkesbury–Nepean River catchment.

Port Jackson Bay

The Sydney Basin bioregion includes all or parts of six major river basins or river regions. These are the Hawkesbury River, Shoalhaven River, Sydney Coast-Georges River, Clyde River-Jervis Bay, Wollongong Coast and Macquarie-Bogan river systems.

The Parramatta River, along with Sydney Harbour, is the most significant waterway in Sydney. Since settlement, the river and the harbour have presented a formidable barrier between the early–European settled southern Farm Cove precinct, to development north of the waterway.

These catchments cover an area of almost 16,000 square kilometres. They extend from north of Lithgow in the upper Blue Mountains, to the source of the Shoalhaven River near Cooma in the south – and from Woronora in the east to the source of the Wollondilly River west of Crookwell.

Storage, rainfall and environmental releases

The Warragamba Water Delivery System supplies water to about 8,700 people in the Penrith, Liverpool and Wollondilly local government areas. The Orchard Hills Water Delivery System supplies water to about 240,000 people in the Penrith, Blue Mountains and Hawkesbury local government areas.

Most of Sydney’s drinking water comes from the Blue Mountains and the Southern Highlands. The Hawkesbury-Nepean River system is the source of the largest volume of Sydney’s drinking water. This river system includes the Hawkesbury–Nepean River and all the smaller rivers that flow into it.

As set out in the Sydney Water Act 1994, Sydney Water’s principal objectives are to protect public health, protect the environment and to be a successful business.

Warragamba Dam spillway is currently releasing water at a rate of 450 gigalitres per day (GL/day) and that rate could increase as inflows to the dam storage continue to rise. (By comparison Sydney harbour is estimated to hold 500 GL).

Warragamba Dam was originally designed and built to withstand floods with an estimated 1 in 1,000 chance of occurring in any one year, i.e. a 1:1,000 Annual Exceedance Probability (AEP), estimated at the time of dam design and construction. This is the maximum flood event that could occur over the dam catchment.

On 2 March 2012, it overflowed for the first time in fourteen years. It overflowed again in 2016 and in March 2021.

300 gigalitres per day

More than 80% of Sydney’s water comes from Warragamba Dam and is treated at Prospect water filtration plant. After treatment, water enters Sydney Water’s network of reservoirs, pumping stations and 21,000 kilometres of pipes to arrive at homes and businesses in Sydney, the Blue Mountains and the Illawarra.

Entry is not allowed to the land along the Warragamba Pipelines and Upper Canal, and the land at Warragamba protecting the water supply infrastructure. Permitted activities in Special Areas – restricted access include walking, camping, fishing, swimming and non-powered boating.

Gordon Dam

When completed in 1960, Warragamba Dam was the world’s tallest and largest domestic water supply dam. It is 142 metres high, 351 metres long and contains 3 million tonnes of concrete.

water running over rocks

Nearly 90 per cent of NSW is now out of drought, according to the latest seasonal update issued by the Department of Primary Industries on Friday. “Favourable spring conditions have supported recovery from the 2017 – 2020 drought in many regions,” the Seasonal Outlook says.

Warragamba Power Station is a hydroelectric power station at Warragamba Dam, New South Wales, Australia. Warragamba has one turbine with a generating capacity of 50 MW of electricity. The power station was completed in 1959 and is now disconnected from the electricity grid.

Colong Foundation for Wilderness campaign manager Harry Burkitt said the documents revealed the real cost of raising Warragamba Dam wall. He said the $1.6 billion figure excluded the World Heritage offset cost of $1.34 billion, which was leaked to the Sydney Morning Herald in late 2020.

Split Rock

Premier Bob Heffron

60 m

During the construction of Warragamba Dam, floods caused work to stop many times to ensure the safety of the workers and the equipment. Since it was completed in 1960, the dam has spilled nearly 50 times.

Warragamba Dam supplies water to more than 5 million people living in Sydney and the lower Blue Mountains. Water flows by gravity through a valve house into two pipelines that feed the raw water to Prospect water filtration plant and via off-takes to smaller filtration plants at Orchard Hills and Warragamba.

Burdekin Dam

The Federation Drought from 1895 to 1903 was the worst in Australia’s history, if measured by the enormous stock losses it caused.