The Condamine–Balonne rivers catchment is one of the largest catchments in the Murray–Darling Basin. The main rivers of the catchment, the Condamine and the Maranoa, rise in elevated country in Queensland. However, two-thirds of the catchment is flat floodplain country, with a complex system of rivers and creeks joining and breaking away from the Balonne River.
While a few main waterways of the catchment flow to the Barwon–Darling river system, most end in lakes and wetlands in south west Queensland and north-west New South Wales. Most of the catchment is located in Queensland with only 16% in New South Wales.
The catchment's extensive floodplains provide habitat for a diverse range of plants and endangered plant communities. The region also provides habitat for waterbirds, native fish and many vulnerable and endangered species. There are several wetlands of national importance in the region including the Ramsar-listed Narran Lake Nature Reserve.
The Condamine–Balonne catchment is home to almost 10% of the population of the Basin. Toowoomba, the largest centre, has a population of around 150,000. Given the highly urbanised population compared with other catchments, wholesale and retail trade and health and community services are important employment sectors. The region is significant for its agricultural diversity, with a wide range of winter and summer crops produced on the Darling Downs, as well as very large cotton production areas in the west.
Snapshot
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Catchment area
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13% of the Murray–Darling Basin
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Contribution to Basin water
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8.5%
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Annual stream flow
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1,305 GL (St George)
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River length
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1,195 km (Condamine, Balonne and Culgoa channel)
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Tributaries
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Maranoa River, Nebine Creek
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Distributaries
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Narran, Bokhara, Ballandool, Birrie and Culgoa rivers, and Briarie Creek
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Towns include
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Warwick, Toowoomba, Dalby, Roma, St George
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Water storages
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Beardmore Dam (94 GL), Leslie Dam (106 GL), Cooby Dam (21 GL)
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Water users
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Urban centres, agriculture
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The landscape and its water
The Condamine River rises on the Darling Downs in the Queensland. The river flows north-west past Dalby and onward to Chinchilla. It then flows south-west to the plains, where it meets the Dogwood Creek and becomes the Balonne River, near Surat.
The Maranoa River rises in the Carnarvon National Park and flows south-east through the town of Mitchell before joining the Balonne River at Lake Kajarabie (Beardmore Dam), just upstream of St George.
Downstream of St George, the Balonne becomes a network of channels, waterholes and floodplains that form the Narran, Bokhara, Ballandool and Culgoa rivers, and the Briarie Creek. After crossing the border into New South Wales, the Bokhara River splits, forming the Birrie River which flows south-west and joins the Culgoa. In times of very high flow, the Bokhara and Culgoa rivers flow into the Barwon–Darling River downstream of Brewarrina.
The Nebine Creek is the main waterway of the western part of the catchment. It flows south from near Morven in south-west Queensland and meets the Culgoa River in northern New South Wales.
The landscape of the Condamine–Balonne catchment is diverse, ranging from tablelands and slopes in the east; gorges in the north-west; to semi-arid plains in the south-west. Elevations in the Great Dividing Range (where the Condamine River rises) can be up to 1,400 m whereas the flat expansive floodplains that cover nearly two-thirds of the catchment have an elevation of between 100 m and 200 m above sea level.
The eastern part of the catchment has an annual average rainfall of 600–800 mm. The Maranoa Valley has an average annual rainfall of 500–600 mm, and the floodplains of the south-west have an average 300–500 mm. Rainfall throughout the catchment is summer-dominant and the climate is described as subhumid and subtropical. Evaporation rates in the south-west of the catchment are very high.
The Condamine–Balonne catchment is above an extensive and deep groundwater system, the Great Artesian Basin. There is some interaction between water of the Great Artesian Basin and overlying surface water or shallow groundwater (contained in near-surface aquifers). Shallow groundwater exists in alluvial aquifers that are associated with the major rivers and creeks of the region. Basalt and sandstone aquifers exist in the upper and mid catchment, and groundwater also exists in sand beds and gravel layers in the mid to lower catchment. Recharge to the aquifers occurs through rainfall throughout the catchment, flooding in the lower catchment, and lateral flow between the different groundwater systems.
People, industry and water use
The lands of the Condamine–Balonne catchment have been important to First Nations people for thousands of years. Many First Nations people retain a connection with the region, and their history, culture and livelihoods are closely intertwined with its river systems. First Nations of the region include Barunggam, Bidjara, Bigambul, Euahlayi, Gomeroi/Kamilaroi, Giabel, Githabul, Gunggari, Guwamu/Kooma, Jarowair, Kambuwal, Mandandanji, Murrawarri, and Wakka Wakka.
European settlers started leasing large tracts of the Darling Downs in the 1830s and then purchased land after 1840 for wool and beef production. Further development of the region and the building of railways led to increased cropping, the main agricultural pursuit in recent times. Pastoral runs were taken up in the south-west of the region from about the 1860s. Areas with access to good quality water have become successful cropping regions.
Most of the catchment's population lives on the Darling Downs. Toowoomba is the largest centre with the nearby towns of Warwick and Dalby each having about 12,000 people. St George is the largest centre in the west of the catchment with a population of over 2,000.
Land use is dominated by cattle and sheep grazing on dryland pasture. Grain and cotton crops are a significant contributor to the regional economy and are grown under dryland and irrigated farming respectively.
The Commonwealth Scientific and Industrial Research Organisation (CSIRO) reports on average 53% of available surface water was extracted for use annually, which is extremely high compared with other catchments in the Basin. The high level of use in the Condamine–Balonne has significantly reduced end-of-system flows, particularly into the Narran Lakes system.
Groundwater extraction is on average 18% of the total water use (surface and groundwater) in the region. Shallow groundwater is used primarily for irrigation of cotton, fodder and grain crops, but also for domestic, stock, intensive livestock, commercial and industrial purposes. Extraction in most areas, but especially in the upper Condamine region, generally exceeds potential rainfall recharge.
Water from the Great Artesian Basin is the primary source of groundwater in the mid-Condamine and Culgoa–Balonne sub catchments. Salinity of the water is variable but generally adequate for stock and domestic use; however, high sodium levels preclude general irrigation use.
Regulation of water in the catchment
Compared with other catchments in the Basin, the extent of river regulation in the Condamine–Balonne is low. Public dams account for only 13% of stored water in the catchment. The 2 largest public storages are Leslie Dam (106 GL) near Warwick and Beardmore Dam (82 GL) near St George, which were built in the 1960s to secure town water supply as well as irrigation supplies.
While there are irrigation supply schemes, licensed water harvesting for irrigation via interception and on-farm storage of floodwater and overland flow, supports most of the irrigated agriculture in the region.
Environmental importance
The floodplains of the Condamine–Balonne catchment are ecologically significant because they support endangered ecological communities, such as the brigalow–gidgee woodland/shrubland in the Mulga Lands and Darling Riverine Plains Bioregions. The wetlands support a diverse range of flora and fauna providing habitat for migratory birds and vulnerable and endangered species, such as silver perch, Murray cod, freckled duck, Australian painted snipe, the great egret and the cattle egret.
Wetlands of national importance include the Great Artesian Basin Springs, Lake Broadwater, The Gums Lagoon, the Culgoa River Floodplain and Dalrymple and Blackfellow creeks.
The lower Balonne is a complex floodplain channel system where a number of nationally significant wetlands are located, including the Ramsar-listed Narran Lake Nature Reserve. Annual inflows to the wetlands are highly variable and lakes within the system usually retain water for approximately 4 to 6 months following inundation. The Narran Lakes area also has a very high social and spiritual significance for First Nations people.
The Sustainable Rivers Audit 2 (released in 2012) reported the overall ecosystem health of the Condamine–Balonne valley was poor. With the exception of riverine vegetation which was rated good, the condition of all other aspects of the ecosystem – fish community, macroinvertebrate community, physical form and hydrology – was rated moderate. Of note, there was reduced native species richness and a high percentage of alien fish species in the rivers, resulting in a poor rating for fish community in the lowland zone of the river valley.
Water recovery
The Basin Plan sets Sustainable Diversion Limits, which is how much water can be used in the Murray–Darling Basin, while leaving enough water for the environment. A Sustainable Diversion Limit (SDL) was established for each catchment (or group of catchments) and the reduction in diversions required to achieve the SDL was identified.
The use of environmental water in a specific catchment or region will vary from year-to-year. The Murray–Darling Basin Authority (MDBA) has a Basin-wide environmental watering strategy to guide the use of environmental water across the Murray–Darling Basin to help achieve the best possible results over the long term. Environmental water managers make the day-to-day decisions on what to water and when, in line with the strategy and taking into account seasonal conditions, priorities and the availability of environmental water. Watering decisions are made in consultation with various waterway managers and local landholders.
Catchment or regionally-specific details about environmental water use in the catchment including watering actions, portfolio details and planning, and monitoring of environmental watering, can be found through the Commonwealth Environmental Water Holder or the state government environmental water manager.
More information
Water management
The management of water resources is the responsibility of local, regional, state and Australian governments.
Delivery to households, industry and farms is managed by local councils or regional water authorities.
State government departments for water ensure the network of authorities manages water responsibly and fairly, that catchment and waterway health is maintained or improved through catchment management authorities, and that water saving, re-use and flood management projects are implemented. State governments must manage their state's water resources according to state and commonwealth water legislation.
In addition to directing operations of the regulated River Murray system, the MDBA implements a number of plans and programs to ensure the waters of the Basin, which flow through four states and one territory, are managed cohesively and in the best interests of all water users of the Basin.
Rural water authority
Urban water authority
Catchment management authority
State government water
Use of environmental water
Irrigation water allocation
Maps
