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National Water Account 2017

Sydney: Geographic information

The Hawkesbury-Nepean River is the most significant river system in the region. Surface water is the primary water source and both Hawkesbury-Nepean River and Shoalhaven River play a major role in water supply. The region’s water requirement is mainly for urban water supply and agriculture, which is serviced by an extensive surface water storage network. It includes Burragorang (Warragamba) Reservoir with over two million ML of storage capacity.


For further geographic information about the region scroll down this page or click on the links below:



General description

Area: 30,800 km2 

Population: 5.07 million (Australian Bureau of Statistics [ABS] 2016)

The Sydney region is located on the coast of New South Wales, as shown in Figure R1. It includes the city of Sydney, Australia's most populous city, and is home to 65% of New South Wales' total population. 

The Sydney region spreads from Nowra in the south to Broken Bay in the north; from Lithgow and Goulburn to the west; and to the Pacific Ocean on the east coast (Figure R1).


Figure R2 Contextual map of the Sydney region
Figure R1 Contextual map of the Sydney region


Region definition

The Sydney region is physically defined by the boundaries of the following catchment areas, from north to south as shown in Figure R1.

Hawkesbury River, New South Wales. Source: iStock © leelakajonkij

  • Hawkesbury–Nepean River catchment: Catchment area is 22,000 km². At the top of this catchment, the Wollondilly River joins with the Coxs River at Lake Burragorang and flows as the Warragamba River until the Nepean River confluence. From this point, the Nepean River flows through until its confluence with Grose River, after which it is named the Hawkesbury River. The main tributaries of the Hawkesbury–Nepean River commence in rural areas and national parks. The Hawkesbury River is tidal for the full extent of its length from the confluence with the Grose River.
  • Shoalhaven River catchment: Catchment area is 7,300 km². The Shoalhaven River commences between the Gourock and Minuma ranges. The upstream catchment is primarily rural areas and national parks, while the downstream reach contains small urban areas surrounded by rural areas.
  • Sydney Coast–Georges River and Illawarra catchment: The rivers of metropolitan Sydney and Illawarra catchment are relatively small. The main metropolitan Sydney rivers are the Georges, Woronora and Hacking rivers in the south and the Parramatta River in the north. The main Illawarra rivers are the Minnamurra River and Macquarie Rivulet.

The Sydney region excludes the northeastern subcatchments of the Hawkesbury–Nepean catchment starting from Mangrove Creek. These subcatchments were excluded in the Water Sharing Plan for the Greater Metropolitan Region Unregulated River Water Sources (NSW Office of Water 2011a) and make little contribution to the region's water sources.

The region includes water stored in and transactions related to:

  • surface water storages in the region
  • rivers within the region
  • water held in storages, pipes and infrastructure as part of urban water supply and wastewater systems.

The region excludes water stored in:

  • off-channel water storages and rainwater tanks, such as farm dams and private commercial water storages used to harvest runoff or collect rainwater
  • the landscape, such as soil moisture.

For more information regarding items in this report, please refer to the Water accounting policies.


Land use

The land uses in the Sydney region mainly include urban areas, conservation and natural environment areas, and grazing.

The major population centres with their respective populations for the Sydney region (ABS 2016 ) are:

  • Sydney: 4,321,535
  • Wollongong: 261,896
  • Nowra: 30,853
  • Goulburn: 22,419.

A number of small towns are interspersed throughout the rest of the region including Lithgow, Braidwood and Moss Vale.

The conservation and natural environment, grazing and urban areas make up approximately 55%, 25% and 8% of the region respectively. The land uses within the Sydney region are shown in Figure R2 (Australian Bureau of Agricultural and Resource Economics and Sciences 2016).


Figure R2 Land use in the Sydney region
Figure R2 Land use in the Sydney region


Significant aquatic ecosystems

The Sydney region includes the Towra Point Nature Reserve, an estuarine system and a designated Ramsar wetland, on the southern and eastern shores of Botany Bay. There are also 25 nationally important wetlands listed in the directory of important wetlands in Australia (Department of the Environment 2001).

The Water Sharing Plan for Greater Metropolitan Region Unregulated River Water Sources (NSW Office of Water 2011a) identifies 29 river management zones that were assessed as having high instream values. These were identified according to a number of criteria, including the presence of threatened species or ecological communities that are likely to be sensitive to water abstraction.

Several water sources in the Sydney region are known to host endangered ecological communities. The Hawkesbury–Nepean catchment contains Maroota Sands Swamp Forest and Sydney freshwater wetlands, both of which are highly sensitive to nearby water abstraction. Sydney freshwater wetlands is the name given to the plant community characterised by the assemblage of specific species restricted to freshwater swamps in swales and depressions on sand dunes and low-nutrient sandplain sites in coastal areas (NSW Office of Environment and Heritage 2011). Sydney freshwater wetlands also occur in the Illawarra catchment.

The Water Sharing Plan for Greater Metropolitan Region Unregulated River Water Sources (NSW Office of Water 2011a) also identifies high priority groundwater dependent ecosystems that include wetlands, karst systems and endangered ecological communities. There are 21 karst systems (including the major cave systems of Jenolan, Wombeyan and Bungonia) and five vegetation communities that are also considered to be groundwater dependent.

Figure R3 shows the significant wetlands in the Sydney region.



Figure R3 Significant wetlands in the Sydney region
Figure R3 Significant wetlands in the Sydney region


Significant Indigenous cultural places and practices

Department of Industry, Lands and Water implements the Aboriginal Water Initiative program to improve Aboriginal involvement and representation in water planning and management within New South Wales. The program allows Department of Industry, Lands and Water (formerly known as DPI Water) to monitor the success of water management plans in meeting their statutory requirements including providing water for Native Title rights and recognising spiritual, social, customary and economic values of water to Aboriginal people.

The Kangaroo River is an important area for the Nowra and Illawarra local Aboriginal land councils. The Kangaroo River has been recognised as an area of cultural significance as well as a source of food for Aboriginal communities. The Water Sharing Plan for the Kangaroo River Water Source 2003 (NSW Office of Water 2014) provides for native title rights as basic landholder rights.


Water resources

Surface water is the main water source in the Sydney region. The region's surface water resources were developed to meet Sydney's water needs. The reservoir capacity in the Sydney region is one of the larger in the world per head of population (NSW Office of Water 2010). This capacity is needed due to the region's irregular interannual rainfall runoff patterns and the resultant challenge poses for a reliable water supply. The flows from a number of main rivers are heavily controlled by dams and numerous major weirs.

The other water sources for the region are:

  • groundwater
  • desalinated water supply from the Kurnell desalination plant to the Sydney metropolitan area
  • recycled water supply by Sydney Water Corporation (Sydney Water) and several other local councils
  • inter-basin transfers to the region from the Fish River Water Supply Scheme, a tributary of Macquarie River.


Surface water


There are three main river systems within the Sydney region:

  • Hawkesbury–Nepean River catchment
  • Shoalhaven River catchment
  • Illawarra and metropolitan Sydney catchments.

Figure R4 shows the mean monthly flows and mean monthly rainfall experienced in the Grose River (within the Hawkesbury–Nepean catchment) and the Shoalhaven River. Figure R5 shows the location of selected key gauging stations along these main rivers. Further information about climatic conditions in the region and monthly flows at these stations can be found in Climate and water.

Figure R5 Mean monthly flows along the Grose and Shoalhaven rivers and mean monthly rainfall for the Sydney region

Figure R4 Mean monthly flows along the Grose and Shoalhaven rivers and mean monthly rainfall for the Sydney region



Figure R5 Streamflow gauging stations along the main rivers within the Sydney region
Figure R5 Streamflow gauging stations along the main rivers within the Sydney region

Major storages

Warragamba Dam, New South Wales. Source: WaterNSW© WaterNSW

There is an extensive storage and weir network for capturing streamflows in the Sydney region.

The region's largest storage, Lake Burragorang (Warragamba), with a capacity of 2,031,000 ML, represents 70% of the storage capacity of Sydney region's major storages. These storages provide water for urban centres, industries, power generation and many other minor uses.

Water from the Shoalhaven catchment is able to be diverted to the Hawkesbury–Nepean catchment through the Lake Yarrunga (Tallowa), Bendeela Pondage and Fitzroy Falls storages.

A map of the major storages within the Sydney region is provided in Figure R6.


Figure R6 Major storages in the Sydney region; capacity of each storage is also shown 

Figure R6 Major storages in the Sydney region; capacity of each storage is also shown


A large part of the supply network is managed by WaterNSW, while other water supplies in the area are managed by Shoalhaven City Council, Wingecarribee Shire Council and Sydney Water. More information on the WaterNSW supply network is available from the WaterNSW website.


Intervalley transfers

The Fish River Water Supply Scheme, which is located outside the Sydney region and managed by WaterNSW, delivers water from the Oberon reservoir and Duckmaloi weir to the following major customers:

  • Oberon township
  • Lithgow villages
  • WaterNSW, Blue Mountains storages
  • EnergyAustralia.

The Oberon township is outside the Sydney region boundaries so has not been included in the region's account.

Further, there are intervalley water transfers within the Sydney region linking the Shoalhaven catchment, the Hawkesbury–Nepean catchment and the Sydney coastal catchments. These transfers are not accounted for in this water account as they occur within the region and within the surface water store.



Groundwater is not a major water source in the Sydney region. The Sydney region's groundwater resources are mainly utilised for irrigation and industrial purposes. There are 13 groundwater sources identified in the region. A groundwater source as defined in the Water Sharing Plan for Greater Metropolitan Region Groundwater Sources 2011 (NSW Office of Water 2011b) is one or more places where water naturally occurs below the surface of the ground. 

These groundwater sources are grouped into three types, as follows:

1. Fractured rock  

  • Goulburn
  • Coxs River.

2. Porous rock

  • Sydney Basin South
  • Sydney Basin Richmond
  • Sydney Basin North
  • Sydney Basin Nepean
  • Sydney Basin Coxs River
  • Sydney Central Basin
  • Sydney Basin Blue Mountains.

3. Coastal sands, tertiary sands and alluvial

  • Metropolitan Coastal Sands
  • Maroota Tertiary Sands
  • Botany Sandbeds
  • Hawkesbury Alluvium.

The Water Sharing Plan for the Greater Metropolitan Region Groundwater Sources: Background document (NSW Office of Water 2011c) provides further details about these groundwater sources. For management purposes, these groundwater sources have been sorted into groundwater management units. Figure R7 shows a map of the groundwater management areas in the Sydney region. 


 Figure R7 Groundwater management units within the Sydney region
Figure R7 Groundwater management areas within the Sydney region

Desalinated water

Sydney's desalination plant at Kurnell commenced delivering water on 28 January 2010 (Sydney Water Corporation 2012). It operates at full production capacity when the WaterNSW's total operating storage capacity (2,581,749 ML) falls below 70% and continues to operate until the level returns to 80%. The plant can supply 250 ML of water a day, equivalent to 15% of greater Sydney's current water needs. As part of the plant's commissioning process, it operated continuously for two years until June 2012 to ensure it met planned performance and reliability targets. Since June 2012, the plant has been taken offline and would be brought back online within eight months if the total WaterNSW storage system fell below 70% of capacity.


Water systems

Urban water system

Water supply system

Water supply system in the Sydney region is sourced primarily from surface water.

Sydney Water is the major water utility in the region and provides drinking water to more than five million people across Sydney, the Blue Mountains and the Illawarra. It operates nine water filtration plants and supplies over 1,400 ML/day of drinking water to customers through a network of 243 reservoirs, 150 pumping stations and over 21,784 km of water pipes. About 80% of water is from Warragamba Reservoir. For more information on the urban water supply system in the Sydney region, refer to the Sydney Water website.

Other organisations which provide water supply in the region are Shoalhaven Water, Goulburn Mulwaree Council, Lithgow City Council and Wingecarribee Shire Council.

Wastewater and recycled water system

Sydney Water’s wastewater network consists of 16 wastewater treatment plants,14 water recycling plants and 677 wastewater pumping stations over 25,355 km of wastewater pipes and 577 km of recycled water pipes. A majority of treated wastewater is discharged to waterways, estuary or sea. Recycled water is distributed for urban, agricultural and other uses (See Sydney Water).

Shoalhaven City Council operates nine wastewater treatment plants and among them, four treatment plants; Bomederry, Culburra, Nowra and Shoalhaven Heads wastewater treatment plants are located in Sydney region. Wingecarribee Shire Council, Lithgow City Council and Goulburn Mulwaree Council also operate a few treatment plants. The treated wastewater is mostly discharged to waterways. The small quantity of recycled water produced at these plants are mainly used for plant operations, on-site use and agriculture.


Fish River water supply scheme

WaterNSW1 has a water management licence for the Fish River Water Supply Scheme and operates it in collaboration with the Fish River Customer Council. The members of this council are as follows:

  • WaterNSW
  • Lithgow City Council
  • Oberon Shire Council
  • EnergyAustralia.

The Oberon Shire Council has not been included in the Sydney account because it falls outside of the region boundaries.

More information on the scheme is available under Water rights.

1At the start of 2015 WaterNSW was formed by merging the Sydney Catchment Authority and State Water Corporation.