Adelaide

Area: 5,340 km²

Population: 1,300,000 (ABS 2011)

The Adelaide region is located in the southeast of South Australia, on the east coast of the Gulf St Vincent (Figure P1). It extends from the Barossa Valley in the north to the Fleurieu Peninsula in the south and includes metropolitan Adelaide, the Northern Adelaide Plains and the Western Mount Lofty Ranges (Figure P2). The terrain in the region ranges from flat plains near the coast to steep hills in the east and south.

 Figure P1. Location map of the Adelaide region within Australia

Figure P2. Contextual map of the Adelaide region

The main catchments in the Adelaide region (Figure P3) are:

• Gawler River catchment (4,460 km² in total; 2,804 km² or 64% within the Adelaide region) – contains the Gawler and Light rivers, which both flow west from the northern Mount Lofty Ranges to the Gulf St Vincent. The Gawler River sub-catchment includes the North and South Para rivers tributaries and is entirely within the Adelaide region
• River Torrens (1,190 km²) – the river flows from the Mount Lofty Ranges through Kangaroo Creek Dam to Adelaide and then to the Gulf St Vincent. The Little Para River is also located within the catchment for the River Torrens
• Onkaparinga River (960 km²) – the river flows west from the southern Mount Lofty Ranges to Hahndorf, then through Mount Bold Reservoir to the Gulf St Vincent. Water from the River Murray is pumped into the river at the Hahndorf Dissipater
• Myponga River (155 km²) – the river flows east into Myponga Reservoir and then to the Gulf St Vincent
• Fleurieu Peninsula (1,050 km²) – contains several smaller rivers, such as the Bungala and Yankalilla rivers that flow west into the Gulf St Vincent and the Hindmarsh and Inman rivers that flow southeast into the Southern Ocean.

Figure P3. Map of surface water catchments in the Adelaide region

The major cities and towns in the region, along with their population (ABS 2011), are:

• Adelaide – 1,203,000
• Nuriootpa – 5,000
• Gawler – 20,000
• Victor Harbor – 11,000.

Description of the region

The Adelaide region is physically defined by the catchments that intersect the Adelaide and Mount Lofty Ranges Natural Resource Management (NRM) region, specifically the Fleurieu Peninsula, Myponga, Onkaparinga, Torrens and Gawler catchments (excluding the Light sub-catchment).

The region includes water stored in and transactions related to:

• surface water storages in the region
• river channels within the region
• water held in pipes and infrastructure as part of urban water supply and wastewater networks
• groundwater aquifers beneath the region.

The region excludes water stored in and transactions related to:

• private water storages, such as farm dams and private commercial water storages
• estuarine surface water resources, including but not limited to those covered by the Penrice Exemption to the Natural Resources Management Act 2004
• water held in the landscape, such as soil moisture, and water held in wetlands that are not connected to surface water storages.

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

The dominant land use in the region is agriculture and urban. Further information on land use in the Adelaide region is provided in Table P1 and Figure P4. There are five irrigation districts in the region. Much irrigation water is self-extracted. There is one irrigation scheme delivering water from a prescribed water source and two significant irrigation schemes delivering recycled water. Irrigation water is used for viticulture, horticulture and irrigated pasture.

Overall, manufacturing is not a large user of water in the Adelaide region although some manufacturers are locally intensive water users. Major water intensive industries include wineries, brewing, beverage production, food and fibre processing, concrete and soda production (AMLRNRMB, 2008; Ryan, 2008; Zulfic, Osei-Bonsu & Barnett 2008).

Table P1. Land use in the Adelaide region

Source:ABARES 2010

* This area is less than the total region area reported in General Description above due to the spatial resolution of the land use data. 

Figure P4. Map of land use in the Adelaide region

The region contains several nationally significant wetlands listed in the Directory of Important Wetlands in Australia (Table P2). 

Table P2. Nationally significant wetlands in the Adelaide region

Source: DSEWPC 2011

Water used in the region comes from the following sources:

• surface water including watercourses
• groundwater
• local catchment harvesting
• River Murray water transferred into the region by pipeline
• recycled stormwater and wastewater.

Some surface resources within the region are fully developed, while others have scope for further development (AMLRNRMB 2011). Groundwater resources are generally fully developed; some groundwater resources of the Northern Adelaide Plains and Mt Lofty Ranges are considered to be over-developed (AMLRNRMB 2011).

Recycled stormwater and wastewater are used increasingly for agricultural and municipal irrigation, and industrial purposes. There is scope for further development of recycled water; policies are in place to support this occurring.

Surface water infrastructure

Table P3. Surface water infrastructure in the Adelaide region

Figure P5. Map of surface water infrastructure within the Adelaide region 

Water storages

SA Water manages an extensive network of water storages in the Adelaide region for urban water supply. Information about these storages is presented in Table P4. 

Table P4. Major water storages in the Adelaide region

Watercourses and streamflow

Mean monthly streamflow pattern, volumes and variation at three rivers in the Adelaide region are shown in Figure P6. The locations used to generate these figures are:

• A5050502 on the North Para River, representing conditions in the Gawler catchment
• A5030504 on the Onkaparinga River, representing inflows to Mount Bold Reservoir
• A5020502 on the Myponga River, upstream of Myponga Reservoir, representing inflows to this storage.

Figure P7 provides the location of the stream gauges used to prepare these hydrographs.

Figure P6. Monthly streamflow graphs for North Para (A5050502), Myponga (A5030504) and Onkaparinga (A5020502) rivers; mean monthly rainfall is also shown 

Figure P7. Map of key flow gauging stations along the main rivers within the Adelaide region

Groundwater is an important water resource in the Adelaide region both for irrigation and for stock and domestic supply. The major groundwater resources are:

• Adelaide Plains – Tertiary 1 and Tertiary 2 aquifers
• McLaren Vale – Port Willunga Formation and Maslin Sands aquifers
• Barossa Valley – Upper, Lower and fractured rock aquifers
• Western Mount Lofty Ranges – fractured rock aquifers.

Groundwater generally flows west from the higher rainfall recharge areas in the Western Mount Lofty Ranges towards the St Vincent Basin (Stewart, Banks & Wilson 2009). Lateral flow is the main mechanism for recharge of the coastal aquifers.

Significant areas of groundwater use and groundwater management areas are presented in Table P5.

Table P5. Significant areas of groundwater use and groundwater management areas in the Adelaide region

Recycled wastewater

Recycling of wastewater is increasingly significant to the Adelaide region. Approximately 30% of the wastewater treated by SA Water is used in recycled water applications (OWS 2010). Community Wastewater Management Systems (CWMS) are another source of treated wastewater; they are typically operated by local councils and harvest water from household septic systems. The most significant recycled wastewater schemes in the Adelaide region are presented in Table P6.

Table P6. Recycled waste water schemes in the Adelaide region

*CWMS: Community Wastewater Management System

Source: The Barossa Council website; Kelly, Stevens & White 2003; Council staff at various councils, pers. comm.; SA Water unpublished WTP records, 2010 

Stormwater harvesting

Stormwater harvesting (collection, treatment and use of urban run-off) is also of increasing importance to the Adelaide region. Stormwater schemes are typically operated by councils and involve treating stormwater through constructed wetlands and storage in the aquifer. The current capacity of council stormwater schemes is 7300 ML/year, but many new schemes are in development (OWS 2010; SMA 2009). Treated stormwater is generally used for municipal irrigation and industrial processes, such as wool washing.

Desalinated water

There are more than 25 private and publicly owned desalination plants with an individual capacity greater than 1.8 ML/year in the region. Unlike other regions of Australia, desalination is not currently used to treat sea water and supplement the urban potable water supply system. However, a 100 GL desalination plant at Port Stanvac is under construction and due for completion in late 2012. Desalination is typically used to improve groundwater, wastewater and mains water quality on a small scale to a standard suitable for irrigation, industry and medical purposes. Desalination of groundwater for food, beverages and industrial processes constitutes 95% of the capacity of desalination plants in the region.

Mine, construction and quarry dewatering

Dewatering of aquifers occurs in the Adelaide region to facilitate mining, quarrying and construction activities. Depending on water quality, the water is stored in above ground storages, discharged into nearby watercourses or aquifers, or applied to the landscape.