Adelaide
Physical information

General description

Area: 5,350 km²

Population: Approximately 1.3 million (Australian Bureau of Statistics [ABS] 2011a, 2011b, 2011c).

 

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 ranges from flat plains near the coast to steep hills in the east and south.

 

Figure P1 the Adelaide region within Australia
Figure P1 the Adelaide region within Australia
 

 

Figure P2 Contextual and catchment boundary map of the Adelaide region
Figure P2 Contextual and catchment boundary map of the Adelaide region

 

Region definition

The Adelaide region is physically defined by the hydrological boundaries of the following catchment areas, from north to south (refer Figure P2):

  • Gawler, North Para, and South Para rivers, and tributaries, which flow west from the northern Mount Lofty Ranges to the Gulf St Vincent (2,095 km2) .
  • River Torrens, which flows from the Mount Lofty Ranges through Kangaroo Creek Reservoir to Adelaide and then to the Gulf St Vincent and the Little Para River (1,135 km2).
  • Onkaparinga River, which flows west from the southern Mount Lofty Ranges to Hahndorf, then through Mount Bold Reservoir to the Gulf St Vincent (930 km2).
  • Myponga River, which flows into the Myponga Reservoir and then southwest to the Gulf St Vincent (153 km2).
  • Fleurieu Peninsula, includes several smaller rivers, such as the Bungala and Yankalilla, that flow west into the Gulf St Vincent and the Hindmarsh and Inman rivers that flow southeast into the Southern Ocean (1,037 km2).

For the purposes of this report, the region includes water stored in:

  • 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
  • groundwater aquifers beneath the region
  • irrigation schemes within the region.

The region excludes water stored in:

  • off-channel water storages, such as farm dams and private commercial water storages; however, as farm dams represent an important water resource in the Adelaide region, information on off-channel water stores and transactions is presented in the Supporting information note
  • estuaries
  • water held in the landscape, such as soil moisture, and water held in wetlands that are not connected to rivers.

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

 

Land use

The Adelaide region hosts a diverse range of land uses. Urban land makes up 16% of land use (Figure P3) with major population centres including: 

  • Adelaide metropolitan area (including Gawler)—1,225,235 (ABS 2011a)
  • Barossa region—33,199 (ABS 2011b)
  • Fleurieu Peninsula—46,350 (ABS 2011c).1
1This estimate includes population estimates for Kangaroo Island, which is not part of the Adelaide region; however, this number is small in comparison to the total population for the Fleurieu Peninsula area.

 

The major land users (more than 50%) in the Adelaide region are from key agricultural industries (grazing, dryland, and irrigated agriculture) including wine production, beef and dairy cattle, vegetable growing, and fruit orchards (Figure P3).  Three irrigation schemes operate in the region to supplement existing water resources for the irrigated agriculture industry (refer Water systems). Conservation and natural environments make up 13% of land use throughout the Adelaide region, while forestry and mining account for only minor uses. Further information regarding land uses in the Adelaide region can be found at the South Australian Primary Industries and Regions website.

 

Figure P3  Land use in the Adelaide region
Figure P3 Land use in the Adelaide region

 

Significant aquatic ecosystems

The region contains several nationally significant wetlands listed in the Directory of Important Wetlands in Australia:

  • Cleland Perched Swamps
  • Englebrook Reserve
  • Washpool Lagoon
  • Onkaparinga Estuary
  • Port Gawler and Buckland Park Lake
  • Barker Inlet and St Kilda
  • Illawong Swamp
  • Maylands Swamp
  • Stipiturus Conservation Park (Glenshera Swamp)
  • Gold Diggings Swamp
  • Congeratinga Swamp
  • Upper Boat Harbour Creek Wetlands
  • Upper Hindmarsh River Catchment
 

Water resources

Water used in the region comes from the following sources:

  • surface water including watercourses
  • groundwater including managed aquifer recharge
  • local catchment harvesting
  • River Murray pipeline transfer
  • recycled stormwater and wastewater 
  • desalinated water produced at the Adelaide Desalination Plant.

Some surface water resources within the region are fully developed, while others have scope for further development. This is illustrated in a comparison of demand versus sustainable extraction limit for surface water management zones in the Western Mount Lofty Ranges Prescribed Water Resources Area (PWRA).

Groundwater resources are generally fully developed. Some groundwater resources of the Northern Adelaide Plains Prescribed Wells Area (PWA) and Mount Lofty Ranges are considered to be overdeveloped. This is shown in a comparison of demand versus sustainable extraction limit for groundwater in the Western Mount Lofty Ranges PWRA.

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

The Adelaide Desalination Plant provides a flexible, climate-independent alternative water source to the surface water generated within the Adelaide region or transferred from the River Murray (see the Desalinated water section for more information).

 

Surface water

The Adelaide region surface water resources include the drainage basins described in the General description section of the 'Contextual information'.

 

Rivers

Most of the flow within the region's drainage basins usually occurs from June–October, reflecting the rainfall and potential evapotranspiration pattern of the region, where mean monthly rainfall is higher in May–October and potential evapotranspiration is low. Figure P4 shows the location of representative flow gauging stations on unregulated reaches of the North Para, Onkaparinga and Myponga rivers. Flow data collected at these stations were used to represent the seasonal flow patterns along these rivers in Figure P5.

 

Figure P4  Selected flow gauging stations on the North Para, Onkaparinga and Myponga rivers within the Adelaide region
Figure P4 Selected flow gauging stations on the North Para, Onkaparinga and Myponga rivers within the Adelaide region

 

 Figure P5  Mean monthly flows along the North Para, Onkaparinga and Myponga rivers and mean monthly rainfall for the Adelaide region
Figure P5 Mean monthly flows along the North Para, Onkaparinga and Myponga rivers and mean monthly rainfall for the Adelaide region

 

Storages

Surface water storages and weirs operated by SA Water and used for urban water supply are detailed in Figure P6 and Table P1.

 

Figure P6 Surface water storages and weirs in the Adelaide region
Figure P6 Surface water storages and weirs in the Adelaide region


Table P1  Surface water storages and weirs capacity
Storage Capacity (ML)Dead storage (ML)Purpose
Barossa Reservoir4,51019urban supply
Barossa Weir1360divert water for urban supply
Clarendon Weir3202divert water for urban supply
Gorge Weir240divert water for urban supply
Gumeracha Weir2000divert water for urban supply
Happy Valley Reservoir11,60071urban supply
Hope Valley Reservoir2,764123urban supply
Kangaroo Creek Reservoir19,000300urban supply
Little Para Reservoir20,800188urban supply
Mannum Adelaide Summit Weir4270 
Millbrook Reservoir16,500188urban supply
Mount Bold Reservoir45,90027urban supply
Myponga Reservoir26,800163urban supply
Onkaparinga Summit Reservoir42764urban supply
South Para Reservoir 44,800310urban supply
Warren Reservoir4,77022urban supply
Total198,9781,477 

 

Further information on the Adelaide region's storages, including current levels and volumes, is given on the Bureau of Meteorology's Water storage website. Note that the volumes reported on the Water storage website exclude the dead storage volumes.
 

Groundwater

Groundwater is an important water resource in the Adelaide region for both irrigation and stock and domestic supply. The major groundwater resources are described in Table P2.

 

Table P2 Significant areas of groundwater use and groundwater management areas in the Adelaide region
Groundwater management areaGroundwater areaHydrogeologyPrimary use
Barossa PWRABarossaconfined, unconfined and fractured rock aquifersviticulture
Central Adelaide PWACentral Adelaide—Tertiary 1 and Tertiary 2 aquifersconfined, unconfined and fractured rock aquifersmixed horticulture, industrial, domestic, irrigation of recreational areas
Northern Adelaide Plains PWANorthern Adelaide Plains—Tertiary 1 and Tertiary 2 aquifersmostly confined aquifersmixed horticulture, industrial
McLaren Vale PWAMcLaren Vale—Port Willunga Formation and Maslin Sands aquifersconfined, unconfined and fractured rock aquifersviticulture, horticulture
Western Mount Lofty Ranges PWRAAdelaide Hillsmostly fractured rock aquifersmixed horticulture, irrigated pasture, viticulture
Southern Fleurieu Peninsulamostly fractured rock aquifers with some confined and unconfined aquifers

 

An example subsection of the the Northern Adelaide Plains aquifers is shown in Figure P7.

 

Figure P7 Groundwater system within the Adelaide region
Figure P7 Groundwater system within the Adelaide region

 

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

 

Desalinated water

The Adelaide Desalination Plant, located at Port Stanvac (Figure P7), treats sea water taken from the Gulf St Vincent, providing an additional, climate-independent water source. Desalinated water is mixed with water treated at the Happy Valley Water Treatment Plant before entering the Happy Valley distribution network. The completed North South Interconnection System project enables SA Water to deliver this desalinated water to customers in both Adelaide's northern and southern suburbs.  

The Adelaide Desalination Plant is able to produce up to 100,000 ML/year of water, which is about half of metropolitan Adelaide's annual water demand; however, the plant's production levels will vary depending on customer demand, impacts on other water resources and emergency responses (i.e., in response to flood events).  The use of the desalination plant is balanced with volumes stored in surface water storages and SA Water's River Murray licence to ensure customer demand is met in a sustainable and cost-effective manner.

There are also more than 25 privately and publicly owned desalination plants with an individual capacity greater than 1.8 ML/year in the region. These desalination plants are 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 the small scale desalination plants in the region.

 

Recycled water

Recycling of wastewater is increasingly significant to the Adelaide region. Approximately 30% of the wastewater treated at SA Water's wastewater treatment plants (WWTPs) is used in recycled water applications (Office for Water Security 2010) including agricultural, viticultural, municipal, parks and recreational purposes. A large proportion of the recycled water is provided to two of the irrigation schemes operating in the region.  Recycled water is also injected to groundwater and subsequently recovered for use as part of a managed aquifer recharge scheme. In addition to SA Water's wastewater treatment plants, community wastewater management schemes (CWMS) are another source of recycled water (refer Community Wastewater Management Schemes for further information).

 

Off-channel water storages

Off-channel water storages (or farm dams) are an important water resource in the Adelaide region. The region has in excess of 15,000 off-channel water storages holding more than 39,700 ML of water when full. On average, off-channel water storages harvest around 10% of annual surface water flow, although on a seasonal basis this can be more than 70% in some catchments during the summer and autumn months. Water held in and abstracted from off-channel water storages is used for a combination of purposes including industrial, irrigation, and stock and domestic purposes. Further information on off-channel water stores is presented in the Supporting information note.

 

Stormwater harvesting

Stormwater harvesting (collection, treatment and use of urban runoff) is of increasing importance to the Adelaide region and forms an integral part of the South Australian Government's water security strategy (Office for Water Security 2010). 

There are currently eight stormwater harvesting and reuse projects underway in the Adelaide region, with the collective capacity to harvest approximately 8,000 ML of stormwater annually. The projects involve treating stormwater through constructed wetlands and storage in aquifers. Treated stormwater is generally used for agricultural irrigation, and irrigation of parks and ovals, as well as third-pipe supply to industrial, commercial and residential customers. For further information refer to the Department of Environment, Water and Natural Resources website.

 

Mine, construction and quarry dewatering

Mine dewatering 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. For example, Penrice dewaters the Angaston quarry within the Barossa PWRA (Golder Associates 2008).

 

Water systems

Urban water system

The urban water system includes water and wastewater treatment plants, pipes and tanks, owned and operated by SA Water. Urban water system infrastructure, including the urban water supply area, water treatment plants, desalination plant, wastewater treatment plants and major pipes that are used to service the Adelaide region's urban water needs are depicted in Figure P8.

 

Figure P8 Urban water system infrastructure in the Adelaide region
Figure P8 Urban water system infrastructure in the Adelaide region

 

Key urban infrastructure shown in Figure P8 in the Adelaide region includes:

  • Major pipelines transporting River Murray water into the region for urban water supply.
  • Metropolitan water supply system which includes seven water treatment plants and the north-south interconnection system to provide potable water for urban consumption, including desalinated water.

  • Metropolitan wastewater system, which includes 11 wastewater treatment plants which collect and treat wastewater, providing recycled water and disposing of unused treated wastewater.

Urban users in the Adelaide region are also supplied with water treated at the Swan Reach WTP and Mount Pleasant WTP, which are located outside the region.

More information about the Adelaide urban water system can be found at the SA Water website.


Irrigation schemes

Three major irrigation schemes operate in the Adelaide region.

Virginia Pipeline Scheme (VPS)

The VPS is a public-private partnership between SA Water and Water Infrastructure Group. It services the Virginia and Angle Vale districts in the north of the Adelaide region providing water to irrigators through a large (>120 km) network of pipes. Recycled water from the Bolivar WWTP is provided for the irrigation of 20 different crops, including fresh vegetables.

Barossa Infrastructure Limited (BIL)

BIL services the Barossa Valley providing water to irrigators for viticulture through a network of approximately 189 kms of underground pipes. River Murray water is the primary water source, supplied via the Mannum–Adelaide pipeline and, if required, via the Swan Reach–Stockwell pipeline in case of need. Recycled water supplements this water, received from the Nuriootpa community wastewater management scheme (CWMS). 

Willunga Basin Water Company (WBWC)

WBWC is a reclaimed water scheme owned and operated by its users. It services the McLaren Vale region providing recycled water to irrigators through a network of approximately 120 kms of pipe, predominantly irrigation water for viticulture, but is also used for irrigation of fruit trees, nut crops and flowers. Recycled water from the Christies Beach WWTP is the primary source of water, including water injected to groundwater as part of the Aldinga Aquifer Storage and Recovery Scheme. Recycled water is also received from the Aldinga WWTP and the Willunga CWMS.


Community Wastewater Management Schemes

These schemes harvest water from household septic systems and are typically operated by local councils. They provide recycled water for irrigation of vines and recreation facilities, including provision of recycled water to the region's irrigation schemes. Some of the community wastewater management schemes operating in the Adelaide region are presented in Table P3.

 

Table P3  Community wastewater management schemes in the Adelaide region
Community wastewater management scheme
Capacity (approx.)Purpose
Golden Groveup to 280 ML/year (not yet supplying at capacity)irrigation of parks and recreation facilities
Greenock, Kapunda, Freeling, Roseworthy180 ML/yearirrigation of vines
Kersbrook, Birdwood/Mount Torrens, Charleston, Woodside, Verdununknownirrigation of woodlands
Myponga, Yankalilla, Second Valleyunknownirrigation
NPEC WWTP250 ML/yearirrigation (reuse of winery wastewater)
Nuriootpa, Lyndoch, Penrice, Mount Pleasant, Tanunda, Williamstown, Springton700 ML/yearirrigation of vines
Willunga CWMS340 ML/yearirrigation of vines and recreational facilities (Willunga Basin Water Company)