South East Queensland
Physical information
General description
Area: 21,331 km² (provided by Seqwater)
Population: 3.2 million (Australian Bureau of Statistics [ABS] 2011)
The South East Queensland (SEQ) region is located on the southeast coast of Queensland (Figure P1). It is the home to 72% of Queensland's population (ABS 2011).
The SEQ region, shown in Figure P2, 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 in the north. Mountains exist along the western and southern edges of the region, while coastal plains dominate the east. It contains several large rivers that discharge into the Pacific Ocean.
Figure P2 Contextual map of the South East Queensland region (source data)
Region definition
The SEQ region covered in this report consists of three water resource plan (WRP) areas: Gold Coast, Logan Basin and Moreton. The total WRP area covered in this report is 21,331 km2. It is defined showing the catchments and includes all water resources within or beneath the physical area as shown in Figure P2.
The region report includes:
- water in surface water storages
- water from the Lockyer Valley groundwater management area (GMA) alluvial aquifer; this GMA is a part of the Clarence–Moreton, which is one of 25 management areas within the Queensland section of the Great Artesian Basin (GAB) (Queensland Government Department of Natural Resources and Mines 2012)
- water within urban infrastructure associated with SEQ water grid, off-grid local water supply schemes, wastewater systems and recycled water systems throughout the region
- desalinated water entering the region
- recycled water from the Western Corridor Recycled Water Scheme (WCRWS).
The region report excludes:
- water held in off-channel water storages, such as farm dams and private commercial water storages used to harvest runoff or collect rain water
- water held in the landscape, such as soil moisture
- water held in wetlands that are not connected to rivers
- water held in the GAB except Lockyer Valley GMA because it underlies a small portion of the SEQ region.
Land use
The SEQ region is the most densely populated area of Queensland. It's total resident population is approximately 3.2 million according to 2011Census data (ABS 2011). The resident population of different cities, towns and urban centres within the region is shown in Table P1.
| Locality | Population |
| Brisbane | 1,089,879 |
| City of Gold Coast | 515,202 |
| Moreton Bay | 390,051 |
| Logan | 287,474 |
| Ipswich | 172,200 |
| Redland city | 143,711 |
A number of small towns are interspersed throughout the rest of the SEQ region, including Aratula, Beaudesert, Benarkin, Blackbutt, Boonah, Canungra, Esk, Fernvale, Gatton, Jimna, Kalbar, Kilcoy, Kooralbyn, Laidley, Linville, Lockyer, Lowood, Preston, Rathdowney, Somerset, Toogoolawah, Warrill View and Yarraman. Figure P3 shows the distribution of land use in the SEQ region. Land use activities that are major water users in the region include irrigated agriculture and urban (Queensland Government Department of Natural Resources, Mines and Water 2005, 2006a, 2006b; Queensland Government Department of Natural Resources and Water 2007).
Figure P3 Land use in the South East Queensland region (source data)
Source: Interpreted from Australian Government Department of Agriculture 2014.
Significant aquatic ecosystems
Wetland systems of international and national importance are located in the SEQ region. Further information can be found on Wetlandinfo (Queensland Government Department of Environment and Heritage Protection 2014).The distribution of the wetlands is shown in Figure P4. The wetlands of Moreton Bay, adjacent to the region and affected by outflows from the region, are listed in the Ramsar Convention of Wetlands (Australian Government Department of the Environment, 2015a, 2015b). They cover in excess of 11,000 km², most of which are on coastal islands or near shore marine areas. The habitat ranges from perched freshwater lakes and sedge swamps on the offshore sand islands to intertidal mudflats, marshes, sandflats and mangroves next to the bay's islands and mainlands.
Figure P4 Nationally important wetlands and Ramsar wetlands in the South East Queensland region (source data)
Significant Indigenous cultural places and practices
Prior to European settlement, a reasonably high number of Indigenous people lived in the SEQ region (Jabree Ltd 2013). It is estimated that the watershed areas alone of the Logan, Albert, Coomera, and Nerang rivers contained 1,500 to 2000 Indigenous communities with fairly dense settlements in terms of Aboriginal populations.
The Indigenous people believe that spiritually they are part of the landscape, of which they emphasize four separate elements: landscape: boundaries, pathways, biodiversity matters, and important sites/areas (Choy et al. 2011). These four elements relate in different ways to water within SEQ.
Natural boundaries include 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).
The Indigenous people used pathways formed by passages of land and water to move through the landscapes. Usually, valleys, wildlife corridors, beaches, waterways, channels, currents and tides are recognised as pathways of importance to them.
The Indigenous people have an acute sense of even small biodiversity. In order to track the changes, they use a 'totem' which is a typical animal or plant species that is in some way connected to a clan group, family, or individual. This builds up a strong spiritual connection between the regional landscape and each individual. It is believed that the totem can serve as an indicator of the environmental changes (Choy et al. 2011).
Water resources
Surface water makes up the majority of abstracted and used water resources within the SEQ region, with groundwater abstraction and use limited to various alluvial aquifers located along river valleys. Desalinated and recycled water resources within the region have been developed in recent years.
Based on the water use in relation to total inflows, available water resources and sustainable yield in the Brisbane water supply area, the water resource is moderately developed with surface water management plans in place across the entire region (Australian Government National Water Commission 2007).
Groundwater resources within the region are being developed, with GMAs now present across many high-use alluvial aquifers. It is expected that additional GMAs may be introduced as groundwater use is further developed. Agriculture is the main groundwater users within the SEQ region.
Water stored within the region's surface water storages is mainly for urban use, although some dams also provide flood mitigation measures. For example, as a flood mitigation measure, Wivenhoe Dam is designed to hold back 1.967 million megalitres of extra water on the top of it's 1.165 million megalitres of normal storage.
Recycled water and desalinated water supplement the surface and groundwater resources for urban use and power supply within the region.
Surface water
Figure P5 shows mean monthly flow volumes and rainfall for the four main rivers within the SEQ region: the Albert (Station 145102B), Bremer (Station 143107A), Brisbane (Station 143001C) and Logan (Station 145014A). Typically these rivers have flow throughout the year, except Bremer because most of its flow occurs between December and June. The seasonal flow characteristics of the four rivers reflect the rainfall pattern of the SEQ region, where a large proportion of rainfall occurs between December–March.
Figure P5 Mean monthly flow along the rivers and mean monthly rainfall for the South East Queensland region
Figure P6 Key flow gauging stations along the main rivers within the South East Queensland region
Major storages
Major storages within the SEQ region are defined as storages with a storage capacity greater than 1,000 ML. In addition to the major storages listed in Table P2, numerous public storages with a storage capacity less than 1,000 ML exist within the SEQ region (Figure P7). These are not included in this account as the storage volumes could not be quantified in a way that was complete, neutral, and free from material error in accordance with Australian Water Accounting Standard 1 (Bureau of Meteorology [Bureau] 2012). It is estimated that these smaller storages have a combined total storage capacity of approximately 7,000 ML which is less than 1% of total storage capacity.
Figure P7 Surface water storages in the South East Queensland region
| Water resource plan (WRP) area | Water supply scheme (WSS) | Storage name | Total storage capacity (ML)1 | Dead storage capacity (ML)2 |
| Gold Coast | Nerang | Hinze | 310,730 | 0 |
| Little Nerang | 6,705 | 0 | ||
| Subtotal | 317,435 | 0 | ||
| Logan Basin | Logan River | Bromelton Off-Stream Storage | 8,210 | 0 |
| Cedar Grove Weir | 1,144 | 0 | ||
| Lake Maroon | 44,319 | 0 | ||
| None3 | Leslie Harrison | 24,868 | 0 | |
| Wyaralong | 102,883 | 0 | ||
| Subtotal | 181,424 | 0 | ||
| Moreton | Central Brisbane River and Stanley River | Mount Crosby Weir | 3,430 | 0 |
| Wivenhoe | 1,165,238 | 0 | ||
| Somerset | 379,849 | 0 | ||
| Central Lockyer | Clarendon | 24,276 | 0 | |
| Bill Gunn | 6,947 | 0 | ||
| Cressbrook Creek | Cressbrook Creek | 81,842 | 1,136 | |
| Perseverance | 30,140 | 3,472 | ||
| Lower Lockyer Valley | Atkinson | 30,400 | 0 | |
| Pine Valleys | North Pine | 214,302 | 0 | |
| Warrill Valley | Moogerah | 83,765 | 0 | |
| None3 | Enoggera | 4,567 | 0 | |
| Gold Creek | 801 | 0 | ||
| Lake Kurwongbah | 14,370 | 0 | ||
| Lake Manchester | 26,217 | 0 | ||
| Splityard Creek | 28,700 | 6,400 | ||
| Subtotal | 2,094,844 | 11,008 | ||
| Total SEQ region | 2,593,703 | 11,008 | ||
1Total storage capacity does not include flood mitigation capacity. The volume in storage may be greater than the total storage capacity if the storage was retaining flood water or spilling at the time of measurement.
2All major surface water storages managed or owned by Seqwater have zero dead storage. Seqwater advised that due to installation of pumping systems none of their major surface water storages have any dead storage; all water is now able to be abstracted.
3The storages are operated under additional licences within resource operations plan (ROP).
Groundwater
The primary source of water for the irrigation-dominated upland valleys of the SEQ region (such as the Lockyer Valley) is groundwater extracted from alluvial aquifers. In the south, groundwater use is minor. In certain areas, groundwater throughout the region 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.
The region's groundwater can be categorised into the following types:
- Palaeozoic age basement rocks
- Early–Middle Triassic age metasedimentary rocks
- Permo–Triassic age intrusive rocks
- Mesozoic age sedimentary basins
- Mesozoic age volcanics
- Tertiary age sedimentary basin sediments
- Tertiary age basalts
- Quaternary age valley alluvial fills.
The GAB (Queensland Government Department of Natural Resources and Mines 2012), one of the world's largest groundwater resources with an estimated total stored volume of 65,000 million megalitres, underlies 22% of Australia's land mass including a large portion of Queensland . The groundwater resources in the GAB in Queensland are managed under the Great Artesian Basin Plan 2006 (Queensland Government Office of the Queensland Parliamentary Counsel 2014a) and the Great Artesian Basin Resource Operations Plan 2007 (Queensland Government Department of Natural Resources and Mines 2012). This divides the Queensland component of the GAB into 25 management areas. One of these areas, the Clarence-Moreton management area, is located partially within the SEQ region and is made up of Walloon Coal Measures, Marburg Sandstone, and Helidon Sandstone. 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, through to Rathdowney in the south (Queensland Government Department of Natural Resources and Mines 2012). It underlies the Lockyer Valley, Bremer River Valley and Teviot Brook catchment.
There are four GMAs within the SEQ region (Figure P8): Lockyer Valley, Warrill–Bremer Alluvial, Cressbrook Creek Alluvial and Watercourse Buffer Zone (Queensland Government 2014b). These are all located within the Moreton Water Resource Plan (WRP) area. They have yet to be included in the Moreton resource operations plan (ROP). A model has been developed to estimate the groundwater asset in Implementation Area 1 of the Lockyer Valley GMA. Methods for calculating groundwater assets in the other GMAs in the SEQ region are still under investigation.
Figure P8 The groundwater management areas in the South East Queensland region
Desalinated water
Desalinated water from the Gold Coast desalination plant feeds directly into the SEQ water grid. The region's storages have been full or near full since December 2010, hence the plant has been operating in 'hot standby' mode since that time to minimise operating costs. With the region's storages full or near full, the Gold Coast desalination plant has been operating in 'hot standby' mode to minimise operating costs since December 2010. Under this mode, the plant will typically produce up to 25 ML/day twice a week, with no production in between. This small amount of production is needed to keep the membranes wet and the water in the pipes fresh, while retaining the capacity to increase production to 44 ML/day (33%), 88 ML/day (66%), or 133 ML/day (100%) within 24–48 hours whenever required.The plant may also be called on if there are interruptions to supply in other parts of the SEQ water grid.
Water systems
Urban water system
Major urban infrastructure within the SEQ region are illustrated in Seqwater major assets maps (Seqwater 2015a).
Potable water is supplied to residents across much of the region. In the heavily populated areas around Brisbane, City of Gold Coast, Logan City and Ipswich, potable water is supplied through the SEQ water grid; however a number of SEQ residents live in communities where the drinking water supplies are not directly connected to the water grid. These communities obtain water from a range of sources including unregulated rivers, groundwater and recycled water, with varying levels of security.
The SEQ water grid was established in July 2008 to connect water supplies and treatment facilities across the region. The grid comprises an infrastructure network of treatment facilities and two-way pipes that move water between new and existing sources across the region. It provides the whole of SEQ with access to more water sources and is both dependent on climatic conditions (surface water storages) and resilient to climatic conditions (desalination and purified recycled water). The network includes 600 kilometers 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 26 major surface water storages, 51 weirs, 37 operational water treatment plants (WTPs) and 14 groundwater bore fields. The roles of water retailers within the SEQ region are reported in Table A2 in the Organisations responsible for water management section of 'Contextual information'.
There is also a water pipeline between Wivenhoe Dam and Cressbrook Dam for supplying raw water to Toowoomba Regional Council, if there is any shortage of water.
More information on the SEQ region's urban water systems can be found in the Urban water system section of 'Water resources and systems' and in the Australian Water Resources Assessment 2012 (Bureau of Meteorology 2013).
Recycled water
Two main recycled water schemes exist within the SEQ region: recycled water treatment plant at Pimpama–Coomera of the City of Gold Coast and the Western Corridor Recycled Water Scheme (WCRWS).
Gold Coast residential supply
Class A+ recycled water is supplied to 6,706 customers, of which 6,450 are residential (for toilet-flushing and external use) and 256 are non-residential (industrial use) in the Pimpama–Coomera area of the City of Gold Coast .
The recycled water treatment plant is part of the Pimpama–Coomera Waterfuture Master Plan.
Power station supply
The WCRWS provides purified recycled water to power stations and fertiliser industries and potentially agricultural users. It will also supplement the region's drinking water supply by supplying Wivenhoe storage when its levels fall to 40%.
The WCRWS forms part of the SEQ water grid, and the power stations, namely the Swanbank B and Swanbank E power stations (located within the SEQ region) and the Tarong and Tarong North power stations (located outside the SEQ region) are the main customers for the recycled water. Treated effluent from six wastewater treatment plants (WWTPs) is further treated to purify recycled water at three separate advanced water treatment plants (AWTPs) located at Bundamba, Gibson Island and Luggage Point.
When all three AWTPs are operating at capacity, the WCRWS has a capacity of 232 ML/day, subject to the availability of inflowing water from the WWTPs that supply the AWTPs.
Water resources outside the region
The SEQ water grid (SEQ Water Grid Manager 2012) extends beyond the northern and eastern boundaries of the National Water Account's SEQ region, suppling and sourcing water from both within and outside of the region. As demand in these outside areas is generally less than the available supply, some of the surplus is transferred into the SEQ region via the SEQ water grid. These are considered to be inter-region transfers, and include water transferred from the Mary Basin north of the region, and groundwater transferred from North Stradbroke Island and Bribie Island.