The Murray–Darling Basin is a geographical area in the interior of south-east Australia, encompassing the drainage basin of the tributaries of the Murray River, Australia's longest river, and the Darling River, a right tributary of the Murray and Australia's third-longest river. The Basin, which includes six of Australia's seven longest rivers and covers around one-seventh of the Australian landmass, Located west of the Great Dividing Range, it drains southwest into the Great Australian Bight and spans most of the states of New South Wales and Victoria, the Australian Capital Territory, and parts of the states of Queensland (the lower third) and South Australia (the southeastern corner).
The Basin is in length, with the Murray River being long. Most of the basin is flat, low-lying and far inland, and receives little direct rainfall. The many rivers it contains tend to be long and slow-flowing, and carry a volume of water that is large only by Australian standards.
The Snowy Mountains Scheme provides some security of water flows to the Murray–Darling Basin, providing approximately 2,100 gigalitres (7.4×10<sup>10</sup> cu ft) of water a year to the Basin for use in Australia's irrigated agriculture industry, which is worth about A$3 billion per annum, representing more than 40% of the gross value of the nation's agricultural production.
The original inhabitants
The Basin has been home to a large number of Aboriginal people whose traditional lifestyle and cultures have been gradually altered by the arrival of Europeans, while others were outright killed by the settlers. Although some tribes organised resistance, such as the Maraura, whose territory lay around the Rufus River above Renmark and the Tanganekald near The Coorong, many were eventually either killed, exiled, or succumbed to disease. Contemporary organised political associations of First Nations communities, such as the Murray Darling Rivers Indigenous Nations, continue to advocate for protection and self-governing management of water resources across the Basin.
Native fauna
The Murray–Darling Basin is home to many native animal species. The true numbers may not be known, but a fairly confident estimate has been made of these animals and the current status of their population. The study found that there were:
- 80 species of mammals, with 62 extinct and 10 endangered
- 55 species of frogs, with 18 endangered
- 46 species of snakes, with five endangered
- five species of turtles, with none endangered
- 34 species of fish, with up to half of them either threatened or of conservation significance
Historical records show that the previous abundances of fish provided a reliable food source. The bountiful fish became concentrated when the early stages of a flood left shallow water across the floodplain. Species affected were Murray cod, golden perch, silver perch and bony herring. As the cleanup began, police attributed the cause to (naturally occurring) hypoxic blackwater. Initial investigations by the New South Wales Environment Protection Authority (EPA) included single water samples at six sites and were criticised as inadequate. Subsequently it was announced that the New South Wales government will treat the deaths as a "pollution incident", thus giving the EPA greater investigative powers; earlier testing was described as being primarily intended to ensure public safety.
Introduced species
Four varieties of carp were used to stock up fish dams. Since then they have made their way into the river systems, where they spread quite quickly. Human introduction, possibly by anglers using small carp illegally as live bait, has also increased their distribution. These fish are very mobile, breed rapidly and can survive in very shallow water and through long periods of very low dissolved oxygen content.
Carp are a problem because they feed by sucking gravel from the riverbed and taking all the edible material off it, before returning the rest to the water. This stirs up all the sediment, reducing the quality of the water. A project for developing daughterless carp shows promise for eliminating carp from the river system.
Cane toads have entered the upper reaches of the Darling Basin and there are several reports of individuals being found further down the system. Cane toads compete with native amphibians and are toxic to native carnivores.
Phyla canescens has invaded wetlands and floodplains with heavy clay soils in the Murray–Darling Basin, to the detriment of the native vegetation; the plant does best in habitats that are inundated occasionally, although it cannot compete with the grass Paspalum distichum and the sedge Eleocharis plana in more heavily inundated sites.
Physiography
This area is one of the physiographic provinces of the larger East Australian Basins division, and encompasses the smaller Naracoorte Platform and Encounter Shelf physiographic sections.
Total water flow in the Murray–Darling Basin 1885 to the present has averaged around per year. This is the lowest rate of the world's major river systems. About 6.0 percent of Australia's total rainwater falls into the Basin. In most years only half of this quantity reaches the sea and in dry years much less. Estimated total annual flows for the Basin have ranged from in 1902 to in 1956. Despite the magnitude of the Basin, the hydrology of the streams within it is quite varied.
These waters are divided into four types:
- The Darling and Lachlan basins. These have extremely variable flows from year to year, with the smallest annual flow being typically as little as 1 percent of the long-term mean and the largest often more than ten times the mean. Periods of zero flow in most rivers can extend to months and in the drier parts (Warrego, Paroo and Lower Darling Basins) to years.). Thus, variability of runoff is very high and most of the terminal lakes found in these basins very frequently dry up. Almost all runoff occurs in the winter and spring and, in the absence of large dams for regulation, these rivers are often seasonally dry during summer and autumn.
- A number of small catchments in South Australia, of which the largest are the Angas River flowing through Strathalbyn and the Finniss River further west, are part of the Murray–Darling Basin. These catchments lead to Lake Alexandrina, one of the lakes at the end of the Murray system. The Angas River is often dry in summer because of high levels of water extraction. The Finniss River has permanent flow into Lake Alexandrina but was cut off by a weir for several years of drought in the early 21st century.
- The Murray, Murrumbidgee and Goulburn (except the Broken River which resembles the southwestern basins) basins. Because these catchments have headwaters in alpine country with relatively young peaty soils, the runoff ratios are much higher than in other parts of the Basin. Consequently, although gross precipitation variability is no lower than in the Lachlan or Darling basins, runoff variability is markedly lower than in other parts of the Basin. Typically these rivers never cease to flow and the smallest annual flow is around 30 percent of the long-term mean and the largest around three times the mean. In most cases the flow peaks very strongly with the spring snow melt and troughs in mid-autumn.
The two principal rivers of the Basin, the Murray and Darling, bring water from the high ranges of the east and carry it west then south through long flat and dry inland areas, often resulting in alluvial channel wetlands, such as The (Great) Cumbung Swamp, at the terminus of the Lachlan and Murrumbidgee Rivers. Nevertheless, these waters are subject to major diversions for municipal drinking supplies and irrigated agriculture that began in the 1890s. These extensive irrigation systems require a reliable supply of water, not the unpredictable flows that characterise the Murray–Darling. However, during "the Big Dry", as the early 2000s drought came to be known, Australian farmers experienced a scarcity unlike ever before. The drought was so severe that numerous rivers and streams such as the Murray–Darling stopped flowing. Eleven of these are protected under the Ramsar Convention of Wetlands of International Importance.
Rivers in the Murray–Darling Basin
<gallery>
File:YarrawongaWeir.jpg|Yarrawonga Weir on the Murray River forms Lake Mulwala, 2010
File:MenindeeDarlingRiver.JPG|Darling River at Menindee, 2009
File:Warrego River.JPG|Warrego River at Cunnamulla, 2010
File:Collarenebri (2).JPG|Barwon River at Collarenebri, 2008
File:Lake Burrendong.jpg |Lake Burrendong, formed at the confluence of the Macquarie River and Cudgegong River, 1995
File:Macquarie River at Bathurst.jpg |Macquarie River at Bathurst, 2009
File:StGeorgeCottonIrrig.jpg |Siphon irrigation of cotton on the Balonne River near St George, 2012
File:Mitchell Maranoa River DSC03260.JPG|Maranoa River at Mitchell, 2005
File:StateLibQld 1 43711 Floodwaters rush under the MacIntyre River Bridge, Goondiwindi, 1921.jpg |Macintyre River in flood at Goondiwindi, 1921
File:Taemas Bridge, NSW, from north.jpg|Taemas Bridge across the Murrumbidgee River, 2011
File:BrindabellaValleyAndGoodradigbeeRiver.jpg |Goodradigbee River in the valley below the Brindabella Ranges, 2005
File:MolongloRiver1920.jpg |Molonglo River at Acton in 1920, prior to the damming of the river to form Lake Burley Griffin
File:Kyalite Wakool River 002.JPG|Wakool River, near Kyalite, 2012
File:Charlton footbridge.JPG |A footbridge of the Avoca River at Charlton, 2005
File:MurchisonGoulburnRiver.JPG|Goulburn River at Murchison, 2009
File:PorepunkahOvensRiver.JPG|Ovens River at Porepunkah, 2007
File:Mitta Mitta in full flow through drought - 6543.jpg|Mitta Mitta River, downstream from Dartmouth Dam, 2007
</gallery>
The rivers listed below comprise the Murray–Darling Basin and its direct significant tributaries, with elevations of their confluence with the downstream river. The tributary with the highest elevation is Swampy Plain River that rises in the Snowy Mountains, below Mount Kosciuszko at an elevation of , and ends merging with the Murray River, descending .
The ordering of the Basin, from downstream to upstream, is:
{| class="wikitable sortable"
|-
!colspan=13|Rivers of the Murray–Darling Basin
|-
!Catchment river !! !! !! !! !! !! !! rowspan=6 colspan=2|Elevation at<br />confluence !!rowspan=7|River mouth !!rowspan=7|States !!rowspan=6 colspan=2|River length
|-
! !!Tributary
|-
! !! !!Tributary
|-
! !! !! !!Tributary
|-
! !! !! !! !!Tributary
|-
! !! !! !! !! !!Tributary
|-
! !! !! !! !! !! !!Tributary
!rowspan=2|m
!rowspan=2|ft
!rowspan=2|km
!rowspan=2|mi
|-
|colspan=7|Murray River
|
| Southern Ocean || NSW, Vic, SA
|
|-
| ||colspan=6|Darling River
|
| Murray || NSW
|
|-
| || ||colspan=5|Paroo River
|
| Darling || Qld, NSW
|
|-
| || ||colspan=5|Warrego River
|
| Darling || Qld, NSW
|
|-
| || || ||colspan=4|Langlo River
|
| Warrego || Qld
|
|-
| || || ||colspan=4|Nive River
|
| Warrego || Qld
|
|-
| || ||colspan=5|Culgoa River
|
| Darling || Qld, NSW
|
|-
| || || ||colspan=4|Birrie River
|
| Culgoa|| Qld
|
|-
| || ||colspan=5|Barwon River (New South Wales)
|
| Darling || NSW
|
|-
| || || ||colspan=4|Bokhara River
|
| Barwon || Qld, NSW
|
|-
| || || ||colspan=4|Namoi River
|
| Barwon || NSW
|
|-
| || || || ||colspan=3|Mooki River
|
| Namoi || NSW
|
|-
| || || || ||colspan=3|Peel River (New South Wales)
|
| Namoi || NSW
|
|-
| || || || || ||colspan=2|Cockburn River
|
|Peel || NSW
|
|-
| || || || ||colspan=3|Manilla River
|
| Namoi || NSW
|
|-
| || || || ||colspan=3|Macdonald River (Bendemeer)
|
| Namoi || NSW
|
|-
| || || || || ||colspan=2|Cobrabald River
|
| Macdonald || NSW
|
|-
| || || ||colspan=4|Gwydir River
|
| Barwon || NSW
|
|-
| || || || ||colspan=3|Horton River
|
| Gwydir || NSW
|
|-
| || || || ||colspan=3|Moredun Creek
|
| Gwydir || NSW
|
|-
| || || || ||colspan=3|Rocky River (New South Wales)
|
| Gwydir || NSW
|
|-
| || || ||colspan=4|Mehi River
|
| Barwon || NSW
|
|-
| || || ||colspan=4|Moonie River
|
| Barwon || NSW
|
|-
| || || ||colspan=4|Boomi River
|
| Barwon || NSW, Qld
|
|-
| || || ||colspan=4|Macquarie River
|
| Barwon || NSW
|
|-
| || || || ||colspan=3|Castlereagh River
|
| Macquarie || NSW
|
|-
| || || || ||colspan=3|Talbragar River
|
| Macquarie || NSW
|
|-
| || || || || ||colspan=2|Coolaburragundy River
|
| Talbragar || NSW
|
|-
| || || || ||colspan=3|Little River (Dubbo)
|
| Macquarie || NSW
|
|-
| || || || ||colspan=3|Bell River (New South Wales)
|
| Macquarie || NSW
|
|-
| || || || ||colspan=3|Cudgegong River
|
| Macquarie || NSW
|
|-
| || || || ||colspan=3|Turon River
|
| Macquarie || NSW
|
|-
| || || || || ||colspan=2|Crudine River
|
| Turon || NSW
|
|-
| || || || ||colspan=3|Fish River (New South Wales)
|
| Macquarie || NSW
|
|-
| || || || || ||colspan=2|Campbells River
|
| Fish || NSW
|
|-
| || || || || ||colspan=2|Duckmaloi River
|
| Fish || NSW
|
|-
| || || ||colspan=4|Weir River (Queensland)
|
| Barwon || Qld, NSW
|
|-
| || || ||colspan=4|Balonne River
|
| Barwon || Qld
|
|-
| || || || ||colspan=3|Maranoa River
|
|Balonne || Qld
|
|-
| || || || || ||colspan=2|Merivale River
|
|Maranoa || Qld
|
|-
| || || || ||colspan=3|Condamine River
|
|Balonne || Qld
|
|-
| || || ||colspan=4|Macintyre River
|
| Barwon || NSW, Qld
|
|-
| || || || ||colspan=3|Dumaresq River
|
|Macintyre || NSW
|
|-
| || || || || ||colspan=2|Macintyre Brook
|
|Dumaresq || Qld
|
|-
| || || || || ||colspan=2|Beardy River
|
|Dumaresq || NSW
|
|-
| || || || || ||colspan=2|Pike Creek (Queensland)
|
|Dumaresq || Qld
|
|-
| || || || || ||colspan=2|Mole River (New South Wales)
|
|Dumaresq || Qld
|
|-
| || || || || || ||Deepwater River
|
|Mole || NSW
|
|-
| || || || || || ||Bluff River (New South Wales)
|
|Mole || NSW
|
|-
| || || || || ||colspan=2|Severn River (Queensland)
|
|Dumaresq || Qld, NSW
|
|-
| || || || ||colspan=3|Severn River (New South Wales)
|
|Macintyre || NSW
|
|-
| || || || || ||colspan=2|Beardy Waters
|
| Severn (NSW) || NSW
|
|-
| || ||colspan=5|Bogan River
|
| Darling || NSW
|
|-
| || || ||colspan=4|Little River (Parkes)
|
| Bogan || NSW
|
|-
| ||colspan=6|Murrumbidgee River
|
| Murray || NSW, ACT
|
|-
| || ||colspan=5|Lachlan River
|
| Murrumbidgee || NSW
|
|-
| || || ||colspan=4|Belubula River
|
| Lachlan || NSW
|
|-
| || || ||colspan=4|Boorowa River
|
| Lachlan || NSW
|
|-
| || || ||colspan=4|Abercrombie River
|
| Lachlan || NSW
|
|-
| || || || ||colspan=3|Isabella River (New South Wales)
|
| Abercrombie || NSW
|
|-
| || || || ||colspan=3|Bolong River
|
| Abercrombie || NSW
|
|-
| || ||colspan=5|Tumut River
|
| Murrumbidgee || NSW
|
|-
| || || ||colspan=4|Goobarragandra River
|
| Tumut || NSW
|
|-
| || || ||colspan=4|Doubtful Creek
|
| Tumut || NSW
|
|-
| || ||colspan=5|Yass River
|
| Murrumbidgee || NSW
|
|-
| || ||colspan=5|Goodradigbee River
|
| Murrumbidgee || NSW
|
|-
| || ||colspan=5|Crookwell River
|
| Murrumbidgee || NSW
|
|-
| || ||colspan=5|Molonglo River
|
| Murrumbidgee || NSW, ACT
|
|-
| || || ||colspan=4|Jerrabomberra Creek
|
| Molonglo || NSW, ACT
|
|-
| || || ||colspan=4|Sullivans Creek
|
| Molonglo || NSW, ACT
|
|-
| || || ||colspan=4|Queanbeyan River
|
| Molonglo || NSW, ACT
|
|-
| || ||colspan=5|Cotter River
|
| Murrumbidgee || ACT
|
|-
| || || ||colspan=4|Paddys River (Australian Capital Territory)
|
| Cotter || ACT
|
|-
| || || || ||colspan=3|Tidbinbilla River
|
| Paddys || ACT
|
|-
| || || || ||colspan=3|Gibraltar Creek
|
| Paddys || ACT
|
|-
| || ||colspan=5|Gudgenby River
|
| Murrumbidgee || ACT
|
|-
| || || ||colspan=4|Naas River
|
| Gudgenby || ACT
|
|-
| || || ||colspan=4|Orroral River
|
| Gudgenby || ACT
|
|-
| || ||colspan=5|Bredbo River
|
| Murrumbidgee || NSW
|
|-
| || || ||colspan=4|Strike-a-Light River
|
| Bredbo || NSW
|
|-
| || ||colspan=5|Numeralla River
|
| Murrumbidgee || NSW
|
|-
| || || ||colspan=4|Big Badja River
|
| Numeralla || NSW
|
|-
| || || ||colspan=4|Kybeyan River
|
| Numeralla || NSW
|
|-
| ||colspan=6|Wakool River
|
| Murray || NSW
|
|-
| || ||colspan=5|Niemur River
|
| Wakool || NSW
|
|-
| ||colspan=6|Edward River (an anabranch)
|
| Murray || NSW
|
|-
| ||colspan=6|Little Murray River (Victoria)
|
| Murray || Vic
|
|-
| ||colspan=6|Loddon River
|
| Murray || Vic
|
|-
| ||colspan=6|Avoca River
|
| Murray || Vic
|
|-
| ||colspan=6|Little Murray River (New South Wales)
|
| Murray || NSW
|
|-
| ||colspan=6|Goulburn River, Victoria
|
| Murray || Vic
|
|-
| || ||colspan=5|Broken River (Victoria)
|
| Goulburn || Vic
|
|-
| || ||colspan=5|Yea River
|
| Goulburn || Vic
|
|-
| || || ||colspan=4|Murrindindi River
|
| Yea || Vic
|
|-
| || ||colspan=5|Acheron River
|
| Goulburn || Vic
|
|-
| || || ||colspan=4|Little River (Cathedral Range)
|
| Acheron || Vic
|
|-
| || || ||colspan=4|Steavenson River
|
| Acheron || Vic
|
|-
| || || || ||colspan=3|Taggerty River
|
| Steavenson || Vic
|
|-
| || ||colspan=5|Rubicon River
|
| Goulburn || Vic
|
|-
| || || ||colspan=4|Royston River
|
| Rubicon || Vic
|
|-
| || ||colspan=5|Big River (Goulburn River, Victoria)
|
| Goulburn || Vic
|
|-
| || ||colspan=5|Delatite River
|
| Goulburn || Vic
|
|-
| || ||colspan=5|Howqua River
|
| Goulburn || Vic
|
|-
| || ||colspan=5|Jamieson River
|
| Goulburn || Vic
|
|-
| ||colspan=6|Campaspe River
|
| Murray || Vic
|
|-
| || ||colspan=5|Coliban River
|
| Campaspe || Vic
|
|-
| || || ||colspan=4|Little Coliban River
|
| Coliban || Vic
|
|-
| ||colspan=6|Ovens River
|
| Murray || Vic
|
|-
| || ||colspan=5|King River, Victoria
|
| Ovens || Vic
|
|-
| || ||colspan=5|Buffalo River (Victoria)
|
| Ovens || Vic
|
|-
| || || ||colspan=4|Dandongadale River
|
| Buffalo || Vic
|
|-
| || || ||colspan=4|Catherine River (Victoria)
|
| Buffalo || Vic
|
|-
| || ||colspan=5|Buckland River (Victoria)
|
| Ovens || Vic
|
|-
| ||colspan=6|Kiewa River
|
| Murray || Vic, NSW
|
|-
| ||colspan=6|Mitta Mitta River
|
| Murray || Vic
|
|-
| || ||colspan=5|Dart River (Victoria)
|
| Mitta Mitta || Vic
|
|-
| || ||colspan=5|Big River (Mitta Mitta River, Victoria)
|
| Mitta Mitta || Vic
|
|-
| || ||colspan=5|Cobungra River
|
| Mitta Mitta || Vic
|
|-
| || || ||colspan=4|Victoria River (Victoria)
|
| Cobungra || Vic
|
|-
| ||colspan=6|Tooma River
|
| Murray || NSW
|
|-
| ||colspan=6|Swampy Plain River
|
| Murray || NSW, Vic
|
|-
| || ||colspan=5|Geehi River
|
| Swampy Plain || Vic
|
|-
|}
Murray–Darling Basin Initiative
Background
The Basin affects five states and territory governments, which according to the Constitution, are responsible for managing water resources. The River Murray Commission was established in 1917. This led to minor reforms in 1982 in which water quality became part of the commission's responsibilities. On 22 November 2012, Tony Burke signed the Murray–Darling Basin Plan, which passed the Australian Parliament's disallowance period on 19 March 2013.
Community consultation
The MDBA's draft Murray–Darling Basin Plan, titled the Guide to the Proposed Murray–Darling Basin Plan, was released in October 2010 as the first part of a three-stage process to address the problems of the Murray–Darling Basin. The Plan was in response to the 2000s Australian drought, and designed to secure the long-term ecological health of the Murray–Darling Basin. This entailed cutting existing water allocations and tree growth environmental flows. The Basin Plan was designed to set environmentally sustainable limits on the quantities of water that may be taken from Basin water resources, to set Basin-wide environmental, water quality and salinity objectives, to develop efficient water trading regimes across the Basin, to set requirements for state water resource plans and to improve water security for all Basin users. It also intends to minimise social and economic impacts whilst achieving the plan's environmental outcomes.
With the release of the Guide to the Proposed Murray–Darling Basin Plan there have been a number of protests and voiced concerns about the plan in rural towns that the MDBA visited to present the plan to consultation meetings. More than 5,000 people attended a MDBA meeting in Griffith where Griffith Mayor, Mike Neville, said the plan would "obliterate" Murrumbidgee valley communities. Other groups also echo this feeling, such as the Victorian Farmers Federation and Wine Group Growers' Australia. Conversely, support for the Murray–Darling Basin plan has been received by various groups, including Australian Conservation Foundation, and Environment Victoria.
New legal advice from Commonwealth government lawyers is changing the plan. The Government's interpretation is that the plan must give equal weight to the environmental, social, and economic impacts of proposed cuts to irrigation.
Environmentalists and South Australian irrigators, at the end of the river in South Australia, say that the authority should stick to its original figure.
In October 2010, a parliamentary inquiry into the economic impacts of the plan was announced.
In late October 2010 the Water Minister, Tony Burke, played down the prospect of a High Court challenge to the Murray–Darling Basin plan, as confusion continued over new legal advice released by the Government. In response to community concerns that MDBA had put environmental issues first over social and economic needs, Burke released new advice on the requirements of the Water Act. Burke stated that the Act does allow for the authority to "optimise" the needs of all three areas, but constitutional lawyer, George Williams, had cast doubts over the interpretation of the laws, stating it could be subject to a legal challenge.
The MDBA announced in November 2010 that it might be forced to push back the release of its final plan for the river system until early 2012.
The then MDBA chairman, Mike Taylor, reassured the public meeting that more work is being done to look at how the proposed cuts would affect regional communities. He stated: "Importantly, we want to make sure the social and economic impacts—which under any sort of scenario is very significant—were fully teased out". Taylor resigned as he allegedly believed that the overriding principle should be the environmental outcome which was in conflict with the Gillard Government and following a period of sustained criticism of the Authority and the implementation of the proposed draft Basin plan. He was replaced by former New South Wales Planning Minister, Craig Knowles.
In late May 2012, the revised plan was forwarded to state water ministers. It did not alter the recommendation to cut of water entitlements.
Following much negotiation between the Commonwealth and State governments and numerous submissions from interested stakeholders and the community, the Basin Plan became law in November 2012 and can now be implemented.
See also
- Climate change in Australia
- Drought in Australia
- Murray–Darling Cap
- List of drainage basins of Australia
- List of Darling River distances
- List of Murray River crossings
- List of Murray River distances
- List of Murrumbidgee River distances
- Murray Basin, the geological sedimentary basin
References
External links
- Murray–Darling Basin Authority
- Murray–Darling Basin Water Budget Project
- Murray Darling Freshwater Research Centre
- River Murray Water Restrictions
- Murray Outback – Guide to the major towns on the Murray and Murray Outback Region.
- Save the Murray – lobby group
- The Basin Plan
- Guide to the Proposed Basin Plan
- Guide to the Basin Plan, Volumes 1 – 21
- Basin Plan – lobby group
;News