South East Queensland: Geographic information
The South East Queensland region has an extensive network of water bodies consisting of creeks, rivers, wetlands, lakes, bays and the Pacific Ocean. The Moreton Bay area contains wetlands of significant ecological importance. Surface water is the main source for consumptive water use, primarily for urban supply. Water supply is provided by the South East Queensland Water Grid.
For further geographic information about the region scroll down this page or click on the links below:
General description
Area: 24,081 km²
Population: 3.27 million (Australian Bureau of Statistics 2016)
The South East Queensland region is located on the southeast coast of Queensland as shown in Figure R1. It is home to 68% of Queensland's population (Australian Bureau of Statistics 2016). The region is bounded by the New South Wales–Queensland State border in the south, the Pacific Ocean in the east, the Great Dividing Range in the west and the headwaters of the Brisbane River and Mary River in the north. Mountains delineate the western and southern edges of the region, while coastal plains dominate the east. The region contains several large rivers that discharge into the Pacific Ocean, as shown in Figure R1.
Figure R1 Contextual map of the South East Queensland region
Region definition
The South East Queensland region includes four water plan (WP) areas: Gold Coast, Logan Basin catchment, Moreton catchment and part of the Mary Basin catchment (see Figure R7 in Water management). The region is physically defined by the surface water catchments as shown in Figure R1.
For the purposes of this report, the region includes water stored in:
- surface water storages
- pipes and infrastructure as part of the urban water supply and wastewater collection
- groundwater aquifers.
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
- wetlands that are not connected to rivers
- the Great Artesian Basin (GAB).
For more information regarding items in this water accounting report, please refer to the Water accounting policies note.
Land use
The South East Queensland region is the most densely populated area of Queensland. Resident populations of major cities, towns and urban centres within the region include (Australian Bureau of Statistics 2016):
- Brisbane: 1,254,209
- Ipswich: 333,748
- City of Gold Coast: 591,570
- Moreton Bay: 444,257
- Sunshine Coast: 357,422
- Logan: 313,785.
A number of small towns are interspersed throughout the rest of the region including Beaudesert, Blackbutt, Esk, Gatton, Kilcoy, Kooralbyn, Laidley and Yarraman. Major land uses by area, as shown in Figure R2, include:
- Grazing: more than 50% of the land area
- Conservation and natural environments: 18% of the land area
- Forestry and agriculture: 12% of the land area
- Urban land use: 8% of the land area.
Figure R2 Land use in the South East Queensland region
Source: Interpreted from Australian Government Department of Agriculture 2016.
Land use activities that are major water users in the region include irrigated agriculture and urban.
Significant aquatic ecosystems
Wetland systems of national and international importance are located in the region, as shown in Figure R3. Further information can be found on the Department of Environment and Heritage Protection website. The wetlands of Moreton Bay listed in the international Ramsar Convention on Wetlands receive outflows from the region. These wetlands cover in excess of 3,200 km², mostly on coastal islands or near shore marine areas. Habitats range from perched freshwater lakes and sedge swamps on offshore sand islands, to intertidal mudflats, marshes, sandflats and mangroves next to the mainland and the bay's islands.
Figure R3 Nationally important wetlands and Ramsar wetlands in the South East Queensland region
Significant Indigenous cultural places and practices
Prior to European settlement, a large number of Indigenous people lived in the South East Queensland region (Jabree Ltd 2013). It is estimated that the Logan, Albert, Coomera and Nerang catchment areas contained 1,500 to 2,000 Indigenous communities.
Choy et al. 2011 identified a large range of indigenous landscape values. Some of the major values relating to water include:
- traditional boundaries, including creeks, rivers, channels, mountain ranges and invented boundaries created through myth and stories for community safety purposes (including forbidden areas, dangerous swamps, lakes and snake habitats)
- women's places, which are strongly correlated with the presence of water
- pathways – passages of land within the regional landscape used for movement – including valleys, wildlife corridors, beaches, waterways, channels, currents and tides
- biodiversity, identified through interpretation of the 'bush calendar' (including animal behaviour, flowering seasons and weather), interpretation of indicators and warning signs (using fauna), and presence and absence of totemic species and habitats
- important sites and areas, including habitation sites and mission sites which are often strongly linked to water.
Water resources
Most of the region's water supply comes from surface water. The region's surface water storages are primarily used for urban supply. Two of the larger storages—Wivenhoe and Somerset—have additional flood storage compartments above their drinking water storage capacity for flood mitigation (see the Seqwater website for more information).
Groundwater use, mainly for agriculture, is limited to various alluvial aquifers located along river valleys. Groundwater resources within the region are being developed, with groundwater management areas established across many of these alluvial aquifers. It is expected that additional groundwater management areas may be introduced as groundwater use is further developed.
Desalinated and recycled water resources within the region have been developed in recent years, and can supplement surface and groundwater resources for urban use and power supply within the region.
The region's water resources are considered to be moderately developed with surface water management plans in place across the entire region (Australian Government National Water Commission 2007).
Surface water
Mean monthly flows at key flow gauging locations on the five main rivers in the region are shown in Figure R4, along with mean monthly area-averaged rainfall for the region. These locations are: Albert River at Bromfleet (Station 145102B), Bremer River at Walloon (Station 143107A), Brisbane River at Gregors Creek (Station 143009A), Logan River at Yarrahappini (Station 145014A) and North Maroochy River at Eumundi (Station 1410009A). The locations of these stations are shown in Figure R5.
Typically, the five main rivers in the region have perennial flow, except Bremer River, which may occasionally cease to flow. The seasonal flow characteristics of these rivers reflect the rainfall pattern of the region, where most rainfall occurs between November and March.
Figure R4 Mean monthly flow along the rivers and mean monthly rainfall for the South East Queensland region
Figure R5 Key flow gauging stations along the main rivers within the South East Queensland region
Storages
Surface water storages are an important source for water supply in the region. These storages, managed by Seqwater, Toowoomba Regional Council and Tarong Energy, are shown in Figure R6. The five largest storages in the region are Wivenhoe (1,165,238 ML), Somerset (379,849 ML), Hinze (310,730 ML), North Pine (214,302 ML), and Wyaralong (102,884 ML). Together they represent approximately 80% of the region's storage capacity.
Figure R6 Surface water storages in the South East Queensland region
Further information on the region's storages, including current storage levels and volumes, is given on the Bureau of Meteorology's Water storage website.
Groundwater
The primary source of water for the irrigation-dominated upland valleys of the South East Queensland region is groundwater extracted from alluvial aquifers. In the south, groundwater use is minor. In certain areas, groundwater is sourced from local confined aquifers for agricultural and domestic uses. Shallow bores are used to access groundwater for garden-watering on the coastal plain.
Aquifers of note include:
- The Lockyer Valley alluvial aquifer, which overlies the Great Artesian Basin (GAB) but is not a part of it. This aquifer is primarily used for irrigation, and is managed as a separate resource under the Moreton water plan.
- The Cooloola Sandmass aquifer, which lies in the Mary Basin water plan area. This aquifer is primarily used by Cooloola Shire Council for the Rainbow Beach town water supply, as well as for commercial and domestic purposes in nearby areas. Groundwater extraction is strictly monitored in order to avoid potential seawater intrusion and impacts on the groundwater–fed wetland systems.
The Great Artesian Basin (GAB) also underlies part of the region. The GAB is one of the world's larger groundwater resources with an estimated total stored volume of 65,000 million megalitres, and underlies 22% of Australia's land mass including a large portion of Queensland (see the Department of Natural Resources, Mines and Energy website for more details). Groundwater resources in the GAB in Queensland are managed under the Water Plan (Great Artesian Basin and Other Regional Aquifers) 2017, which divides the Queensland component of the GAB into 25 management areas. Of these, the Clarence-Moreton management area is located partially within the region and includes the Walloon Coal Measures, Marburg Sandstone and Helidon Sandstone formations. The Clarence–Moreton management area is 400 km in length and 125 km in width; it extends from Toowoomba in the west to Darr Creek in the northwest, Esk in the north, Ipswich in the east and through to Rathdowney in the south. It underlies the Lockyer Valley, Bremer River Valley and Teviot Brook catchment.
Desalinated water
The Gold Coast Desalination Plant is located at Tugun. Desalinated water is blended with other Gold Coast drinking water supplies and joins the South East Queensland Water Grid (SEQ Water Grid). When running at 100% capacity, the desalination plant is capable of providing 133 ML of water per day to the region's drinking water supplies.
From December 2010 the plant has primarily operated in 'hot standby' mode where the plant produces 5 ML/run, three runs per fortnight. The plant can be called on to augment the region's drinking water supply, particularly during weather events or interruptions to supply in other parts of the SEQ Water Grid. The plant is capable of running at 33% of capacity with 24 hours notice and at 100% capacity with 72 hours notice. More than 20 Gold Coast suburbs were supplied with water from the plant during 2016–17 (for five days in August due to maintenance of Molendinar Treatment Plant, six days in March due to maintenance of Mudgeeraba Treatment Plant, and ten days in April during the response to ex-tropical cyclone Debbie).
Water systems
Urban water system
Water service providers, including the Council of the City of Gold Coast, Logan City Council, Redland City Council, Queensland Urban Utilities, and Unitywater, supply potable water to most residents in the region via the South East Queensland Water Grid (SEQ Water Grid). The grid was established in July 2008 to connect water supplies and treatment facilities across the region, and comprises a network of treatment facilities and two-way pipes that move water between various sources across the region. The network includes more than 600 km of reverse-flow pipelines, including the 47 km bi-directional Northern Pipeline Interconnector that moves water from Noosa to Coolangatta in the south. Key components include 22 major surface water storages, 30 operational water treatment plants, six operational recreational water treatment plants and five groundwater bore fields. The roles of water retailers within the South East Queensland region are provided in Organisations responsible for water management.
There is also a water pipeline between Wivenhoe Reservoir and Cressbrook Creek for supplying raw water to Toowoomba Regional Council, if there is any shortage of water.
In a number of 'off grid' communities within the region, drinking water supplies are not directly connected to the water grid. Instead, water is sourced and treated locally.
Recycled water
Two main recycled water schemes exist within the region: a recycled water treatment plant at Pimpama–Coomera of the City of Gold Coast, and the Western Corridor Recycled Water Scheme extending from Brisbane's southwest suburbs towards the city of Ipswich.
Gold Coast residential supply
Class A+ recycled water is supplied for residential use (toilet-flushing and external use) and non-residential use (industrial use) in the Pimpama–Coomera area of the City of Gold Coast .
Power station supply
The Western Corridor Recycled Water Scheme was used to provide purified recycled water to power stations, fertiliser industries and potentially agricultural users. The scheme was decommissioned on 31 March 2015 and is now in care and maintenance mode.
Prior to its decommissioning in March 2015, the scheme formed part of the SEQ Water Grid. Treated effluent from six wastewater treatment plants was further treated to purified recycled water at three separate advanced water treatment plants located at Bundamba, Gibson Island and Luggage Point. The scheme had a total capacity of 232 ML/day, subject to the availability of inflowing water from the wastewater treatment plants that supply the advanced water treatment plants. The Swanbank B (now closed) and Swanbank E power stations (restarted in December 2017 after three years in cold storage) were the main customers for the recycled water within the region, as well as the Tarong and Tarong North power stations located outside the region.
Farm dams
The Department of Natural Resources, Mines and Energy has indicated that there are approximately 1,700 farm dams greater than 0.25 ha in area within the region, with a combined estimated storage volume of 59,080 ML.