South East Queensland
Physical information

Area: 21,544 km² (Healthy Waterways)

Population: 3,178,030 ( Queensland Treasury and Trade, 2012)

The South East Queensland region is located on the southeast coast of Queensland (Figure P1) and its water supply is physically defined by the following hydrological boundaries:

• Moreton Catchment, including the Pine River and Brisbane River
• Logan Basin Catchment, including the Logan River
• Gold Coast Catchment, including the Nerang River.

This region does not include Stradbroke Island, Bribie Island, the Sunshine Coast and Toowoomba.

The South East Queensland region spreads from the New South Wales – Queensland state border in the south, the Pacific Ocean in the east, the top of the Great Dividing Range in the west and the headwaters of the Brisbane River in the north (Figure P2). Mountains exist along the west and southern edge of the SEQ region with coastal plains in the east. The region contains several large, coastal discharging rivers. The major catchments within the region are listed in Table P1.

Figure P1 Location map of the South East Queensland region within Australia

 

Figure P2 Contextual map of the South East Queensland region 

Table P1 Major catchments within the South east Queensland region

Major catchment	Catchment area  (km2)	Water resource plan (WRP) area
Coomera River	489	Gold Coast
Nerang River	498
Pimpama River	171
Tallebudgera Creek and Currumbin Creek	158
Albert River	786	Logan Basin
Logan River	3,076
Tingalpa Creek, Redlands Creek and Eprapah Creek	281
Brisbane River (includes lower, mid and upper Brisbane, Bremer, Lockyer, Stanley, Oxley and Mooloolah)	14,003	Moreton
Caboolture River	468
North and south Pine river	825
Pumicestone Creek	789

Source: (Healthy Waterways)

The South East Queensland region covered in this report consists of three water resources planning areas: Moreton, Logan and Gold Coast. It is physically defined in the section above, and includes all water resources within or beneath the physical area.

The region includes water stored in:

• surface water storages
• the Lockyer Valley groundwater management area (GMA) alluvial aquifer beneath the region
• urban infrastructure associated with South East Queensland water grid, off-grid local water supply systems, wastewater systems and recycled water systems throughout the region
  
• desalinated water entering the region
• recycled water from the Western Corridor Recycled Water Scheme.

The South East Queensland region 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, and water held in wetlands that are not connected to rivers
• water held in the Great Artesian Basin.
  

The major cities, towns and urban centres in the South East Queensland region are shown in Table P2.

Table P2 Major population centres within the South East Queensland region

Locality	Population
Brisbane	1,079,390
Gold Coast	536,480
Moreton Bay	389,680
Logan City	287,470
Ipswich	172,740
Redland City	144,940

Source: (Queensland Treasury and Trade 2012)

A number of small towns are interspersed throughout the rest of the South East Queensland 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.

South East Queensland is the most densely populated area of Queensland. Water use is predominantly urban around Brisbane and the Gold Coast, with irrigated agriculture being a major water user within the rural portion of the region.

Figure P3 and Table P3 show that grazing and conservation are the largest land uses in the region and that water intensive land use is predominantly irrigated agriculture and urban (Department of Natural Resources, Mines and Water 2005; Department of Natural Resources, Mines and Water 2006a; Department of Natural Resources, Mines and Water 2006b). Major agricultural products include dairy, fodder crops, cereal and horticultural crops.

Figure P3 Map of land use in the South East Queensland region

  

Table P3 Land use in the South East Queensland region

Land use	Area (km2)	Area (%)
Conservation and natural environments	3,267	16
Grazing	11,777	56
Forestry	1,541	7
Dryland agriculture	233	1
Irrigated agriculture	639	3
Urban	2,402	11
Other intensive uses	795	4
Mining	3	0
Water	443	2
Total South East Queensland region	21,100	100

Source: Interpreted from  Australian Bureau of Rural Sciences, 2009

The South East Queensland region includes the following 12 nationally important wetlands that are listed in the Directory of Important Wetlands in Australia.

• Carbrook Wetlands Aggregation
• Conondale Range Aggregation
• Dalrymple and Blackfellow Creeks
• Greenbank Army Training Area
• Karawatha Forest Park Wetlands
• Lake Coombabah (only the freshwater component is located within the South East Queensland region)
• Moreton Bay Aggregation (only the freshwater component is located within the South East Queensland region)
• Pine River and Hays Inlet (only the freshwater component is located within the South East Queensland region)
• Upper Coomera River.

Further information can also be found on the Queensland Government Wetland information website.

The wetlands of Moreton Bay, adjacent to the region and effected by outflows from the region, are listed as Ramsar wetlands. 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 the mainland.

Surface water makes up the majority of abstracted and used water resources within the South East Queensland 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. The requirements for supply from these alternative resources declined in 2011–12 due to higher than average rainfall over the region.

The overall surface water resource is highly developed in the South East Queensland region, with surface water management plans in place across the entire region.

Groundwater resources within the region are becoming more developed, with groundwater management areas (GMAs) now present across many high use alluvial aquifers. It is expected that additional GMAs may be introduced as further development of groundwater occurs. Agriculture and urban settlements are the main groundwater users within the South East Queensland region.

Water stored within surface water storages in the region is mainly for urban use. Recycled water and desalinated water supplement the surface and groundwater resources, for urban use and use in power supply.

Details of major storages in the South East Queensland region are listed in Table P4.

Major storages are defined as storages with a maximum storage capacity greater than 1,000 ML. In addition to the major storages listed in Table P4, numerous public storages with a storage capacity less than 1,000 ML exist within the South East Queensland region. These are not included in this account as the storage volume could not be quantified in a way that was complete, neutral and free from material error in accordance with Australian Water Accounting Standard 1. It is estimated that these storages have a combined total storage capacity in excess of 7,000 ML, less than 1% of total storage capacity.

Table P4. Major water storages in the South East Queensland region

Water resource plan (WRP) area	Water supply scheme (WSS)	Storage name	Total storage capacity1	Dead storage capacity2
			(ML)	(ML)
Gold Coast	Nerang	Hinze	310,730	0
		Little Nerang	6,705	0
	Total Gold Coast WRP area		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
	None	Leslie Harrison	24,868	0
		Wyaralong	102,883	0
	Total Logan Basin WRP area		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
	None	Enoggera	4,567	0
		Gold Creek	801	0
		Lake Kurwongbah	14,370	0
		Lake Manchester	26,217	0
		Splityard Creek	28,700	6,400
	Total Moreton WRP area		2,094,844	11,008
Total South East Queensland region			2,593,703	11,008

Notes:

¹ Total 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 waters or spilling at the time of measurement.

² All 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 as all water is now able to be abstracted.

Figure P4 shows mean monthly flow volumes and rainfall in four main rivers within the South East Queensland region: Albert (145102B), Bremer (143107A), Brisbane (143001C) and Logan (145014A) rivers. Gauging stations on these rivers can be seen in Figure P5. Typically these rivers have flow throughout the year, with most of the flow occurring between December and June. The seasonal flow characteristics of these rivers reflect the rainfall pattern of the South East Queensland region, where a large proportion of rainfall occurs from December to March.

Figure P4 Graph of mean monthly flow along the Albert, Brisbane, Bremer and Logan rivers; mean monthly rainfall for the region is also shown




Figure P5 Map of key flow gauging stations along the main rivers within the South East Queensland region

Groundwater extracted from alluvial aquifers is the primary source of water for the irrigation dominated upland valley such as the Lockyer Valley. Groundwater use is minor in the south of the South East Queensland region. Occasionally, 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 groundwater systems of the South East Queensland region 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 Great Artesian Basin (GAB) underlies a large portion of Queensland. The groundwater resources in the GAB in Queensland are managed under the Water Resource (Great Artesian Basin) Plan 2006 and the Great Artesian Basin Resource Operations Plan 2007. This divides the Queensland component of the GAB into 25 groundwater management areas (GMAs). One of these areas, the Clarence Moreton Management Area, is located partially within the South East Queensland 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 wide and extends from Toowoomba in the west to Darr Creek in the northwest, Esk in the north, Ipswich in the east and Rathdowney in the south (Great Artesian Basin Resource Operations Plan 2007). It underlies the Lockyer Valley, Bremer River Valley and Teviot Brook Catchment.

There are four GMAs within the South East Queensland region (Figure P6): Lockyer Valley, Warrill–Bremer Alluvial, Cressbrook Creek Alluvial and Watercourse Buffer Zone (Moreton ROP 2007). These are all located within the Moreton Water Resource Plan area. They have yet to be included in the Moreton Resource Operations Plan. 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 South East Queensland region are still under investigation.

Figure P6 Map of alluvial aquifers in the South East Queensland region

Major urban infrastructure within the South East Queensland region can be seen in the Seqwater infrastructure map.

Potable water is supplied to residents across much of the South East Queensland region. In the heavily populated areas around Brisbane, Gold Coast, Logan City and Ipswich potable water is supplied through the South East Queensland water grid. A number of southeast Queensland residents live in communities that have drinking water supplies not directly connected to the water grid. These communities obtain water from a range of sources with varying levels of security, including unregulated rivers, groundwater and recycled water.

The South East Queensland 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 southeast Queensland access to more water sources, both dependent on climatic conditions (surface water storages) and resilient to climatic conditions (desalination and purified recycled water). The network includes about 600 kilometres of pipelines to move water from areas of surplus to areas of shortfall. Key components include 26 major surface water storages, 47 weirs, 46 water treatment plants and 14 groundwater bore fields. Water retailers within the South East Queensland region can be seen in Figure A2 in the Organisations responsible for water management section of the 'Contextual information'.

Located outside the South East Queensland region, Toowoomba Regional Council (TRC) obtains raw water directly from surface water storages on Cressbrook and Perseverance creeks which are within the region. Potable water is supplied into the region from the Sunshine Coast (via the Northern Pipeline Interconnector) and Stradbroke Island (Eastern Pipeline Interconnector).

More information on the South East Queensland region's urban water systems can be found in the system's interactions with the region section of the Urban system note and Australian Water Resource Assessment 2010.

Desalinated water from the Gold Coast Desalination Plant feeds directly into the South East Queensland water grid. With the region's dams 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 of operation, the plant will typically produce around 25 ML/day of water two days 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 ramp up to produce 44 ML/day (33%), 88 ML/day (66%) or 133 ML/day (100%) within 24 to 48 hours whenever required.

The plant may be called on if there are interruptions to supply in other parts of the South East Queensland water grid.

Recycled water

Two main recycled water schemes exist within the South East Queensland region.

Gold Coast residential supply

Within the South East Queensland region, Class A+ recycled water is supplied to 3,700 homes and businesses in the Pimpama – Coomera area of the Gold Coast for toilet flushing and external use. Industry also receives recycled water.

The recycled water treatment plant is part of the Pimpama – Coomera Waterfuture Master Plan. The Pimpama Coomera recycled water system was not included in this account as data were not available to quantify the volumes with any confidence.

Power station supply

The Western Corridor Recycled Water Project provides purified recycled water to power stations, future industrial customers and, potentially, agricultural users. It will also supplement the region's drinking water supply through supplying Wivenhoe Dam when dam levels fall to 40%.

The Western Corridor Recycled Water Scheme forms part of the South East Queensland water grid and the power stations namely  the Swanbank B and E power stations (located within the South East Queensland region), and Tarong and Tarong North Power Stations (located outside the South East Queensland region) are the main customers of the recycled water. Treated effluent from six wastewater treatment plants is further treated to purified recycled water at three separate advanced water treatment plants located at Bundamba, Gibson Island and Luggage Point.

When all three advanced water treatment plants are operating at capacity, the Western Corridor Recycled Water Scheme has a capacity of 232 ML/day subject to the availability of inflowing water from the wastewater treatment plants that supply the advanced water treatment plants.

Off-channel storages

Off-channel storages exist in the South East Queensland region and are an important water resource for individuals who rely on them for water. There are approximately 1,700 off-channel storages within the region with an estimated storage volume of 59,000 ML.

The South East Queensland water grid (Water grid) extends to the north and east of the National Water Account South East Queensland region, sourcing water from and servicing the Sunshine Coast, Bribie Island and North Stradbroke Island. Surface water resources to the north of the South East Queensland region, in the Mary Water Resource Plan area, supply water into the South East Queensland water grid. North Stradbroke Island and Bribie Island supply groundwater into the South East Queensland water grid. As the demand in these regions is less than the available supply, some of the water supplied from these three sources is transferred into the region via the South East Queensland water grid. This additional water is considered a water resource for the region.