Snapshot
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Catchment area
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3% of the Murray–Darling Basin
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Contribution to Basin water
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–
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Annual stream flow
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–
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River length
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2,500 km total; approx. 1,200 km Hume Dam to Wentworth
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Major tributaries
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Kiewa, Ovens, Goulburn, Campaspe, Loddon, Wakool and Murrumbidgee rivers, Broken Creek
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Major distributaries
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Edward River, Gunbower Creek
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Major towns/cities
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Albury–Wodonga, Yarrawonga, Echuca–Moama, Deniliquin, Swan Hill, Mildura
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Major water storages
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Yarrawonga Weir (118 GL), Torrumbarry Weir (37 GL), mid-Murray storages (58 GL), Mildura Weir (37 GL)
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Key water users
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Irrigated agriculture, urban water supply, stock and domestic
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Summary
The River Murray is Australia's longest river, running a course of 2,500 km from near Mount Kosciuszko in the Australian Alps to the Southern Ocean at Goolwa in South Australia. The catchment description of the River Murray is split into 3 sections – upper, central and lower.
The central River Murray catchment takes in the country on both sides of the River Murray, from Hume Dam in the east, upstream of Albury, to the confluence of the Murray and Darling rivers at Wentworth, in western New South Wales. The central Murray catchment only covers about 3% of the Basin area but many of the major rivers of the Murray–Darling Basin enter the River Murray in this region. These rivers account for over 50% of the inflow of the Basin.
The River Murray is wide and flows strongly and steadily in its central catchment, which is predominantly riverine plain on either side of the river. There are extensive floodplains and wetlands in this part of the catchment, including nationally and internationally significant sites such as the Barmah–Millewa Forest and the Gunbower–Koondrook–Perricoota Forest.
The catchment is highly developed with many large urban centres established on the banks of the River Murray, and many significant dryland and irrigated agricultural industries located within the region. Tourism based around the river environment and water activities are also economically important to the region.
The landscape and its water
The central River Murray catchment is mainly a broad floodplain that contains an intricate network of creeks, floodrunners and billabongs. Sand hills and natural levees associated with some waterways give some relief to an otherwise flat landscape. The River Murray cuts a wide and deep course through the central catchment as its flows westward.
The central catchment starts in the gently rolling foothills of the Great Dividing Range east of Albury. The hills soon give way to an ever-widening floodplain, and for most of the length of the central catchment, broad riverine plains flank either side of the river. The flatness of the landscape is highlighted by the that fact that over 1,200 km the elevation of the river drops from about 150 m at Hume Dam to less than 50 m at the confluence of the Murray and Darling rivers. Average annual rainfall is about 700 mm at the eastern end of the central catchment, but mostly, it ranges from 500 mm down to 300 mm from east to west. Summers in this part of the Murray catchment are hot and dry, and rainfall is received predominantly in winter and spring.
Expansive river red gum forests, and to a lesser extent black box stands, are an iconic feature of the central part of the Murray catchment. Although much of the general region is described as semi-arid, periodic flooding supports large stands of river red gum on land alongside the Murray and its tributaries. Black box stands are common in areas of semi-permanent wetlands on the plains.
In terms of land area, the central River Murray catchment is relatively small, but within this region other major rivers of the Murray–Darling Basin flow into the Murray, creating a significant body of water that flows to the ocean. In the central part of the catchment, the Kiewa, Ovens, Goulburn, Campaspe, Loddon and Murrumbidgee flow into the Murray, accounting for over 50% of the Basin's water. The Darling River brings water down from the northern Basin.
The course of the Murray and several other rivers changed about 25,000 years ago as a result of an uplift of land from Echuca to Deniliquin, called the Cadell Tilt – effectively a large block that stopped the Murray and Goulburn rivers and 2 very large lakes formed. Over time, and with the melting of glaciers in the Great Dividing Range about 20,000 years ago, water headed northwards to create the Edward River, and the Murray created a new course southwards, now called the Barmah Choke, to follow its current course, created by the ancient Goulburn River, to Swan Hill. Green Gully, west of Mathoura is believed to be the former course of the Murray, as are the lower reaches of the Wakool River.
Groundwater in the central Murray catchment is mainly found in the extensive alluvial groundwater systems on the New South Wales side of the Murray. Surface water and groundwater systems in the catchment are highly connected, but whether streams gain or lose water from the groundwater system, varies along the course of the river.
People, industry and water use
The River Murray flows through the traditional land of many First Nations. The river and its floodplains have long been important for sustenance and spirituality. The First Nations associated with the central Murray catchment include the Wiradjuri, the largest Aboriginal Nation in New South Wales, extending from the River Murray to the Macquarie River in the north, and west to Balranald. The east from the Murray and south into the Great Dividing Range, is the traditional land of the Dhudhuroa and Waywurru Nations. The region centred on Echuca, is the traditional land of the Bangerang, Barapa Barapa, Wamba Wamba and Yorta Yorta Nations. The lower stretch of the central Murray catchment includes the traditional land of the Barkindji, Maraura, Muthi Muthi, Nyeri Nyeri, Tati Tati, Wadi Wadi and Weki Weki Nations.
Albury–Wodonga is the largest regional centre in the central Murray catchment, with a population of over 100,000 people (ABS 2011). The twin cities provide a comprehensive range of health, education and professional services to the region, and host a diverse range of industry that grew out of active promotion of decentralisation in the 1970s.
Other major centres in the central catchment include Corowa (population 6,000), Yarrawonga (7,000), Mulwala (2,000), Deniliquin (7,000), Swan Hill (10,000), and Mildura (30,000) (ABS 2011). These centres provide services for residents and agricultural businesses, and often have food manufacturing business based on local or regional produce. Many of the centres located on the River Murray have a strong tourism sector in their local economy. The city of Echuca (population 13,000), located on the confluence of the Campaspe and Murray rivers, is part of the Campaspe catchment but its economy services residents from the central Murray catchment, and it is a popular destination due to its location on the River Murray and rich history associated with river trade and paddle-steamers.
Land use across the central catchment is predominantly dryland agriculture, producing a wide range of cereal, oilseed and legume grain crops, and grazing of sheep and cattle. The region hosts some of the largest irrigation schemes in Australia, which produce broadacre crops, including rice, fodder for intensive animal industries, large area horticultural crops, including wine grapes, table grapes, almonds, olives, citrus and many niche crops.
Over 150,000 hectares (ha) of land along the River Murray is managed for conservation, comprising public land, such as National Parks and state reserves, and private conservation land.
Recreational and tourism activities provide substantial income for main centres, such as Echuca and Yarrawonga, and increasingly, economic diversification opportunities for smaller communities. Overall, the Murray region attracts more than 5 million tourists annually, who come to the region for water sports, fishing, camping, bushwalking, house boating, resort stays, golf and enjoyment of locally-produced wine and food.
The 2008 Water availability in the Murray report by the Commonwealth Scientific and Industrial Research Organisation (CSIRO) was based on the whole Murray catchment, from the mountain headwaters to the Murray Mouth, as well as the lower Darling River catchment, below Menindee. Average annual water use in the region was reported as high with 36% of available water in the Basin. Water use includes diversion for the major irrigation areas of the Murray Valley, northern Victoria, Sunraysia and the Riverland, as well diversion for large urban centres such as Albury–Wodonga, Yarrawonga, Mildura, Murray Bridge, Adelaide and regional centres in South Australia. The Murray region accounts for 11% of total groundwater use in the Basin, with most use occurring in the central and lower River Murray catchment. Groundwater use represented 5–8% of total water use in the reporting region.
Regulation of water in the catchment
The water resources of the River Murray are regulated from the mountains to the sea, to provide water for hydro-electric power generation, urban centres, irrigated agriculture and the environment, throughout the entire river valley (and beyond).
Irrigation development along the Murray commenced in the 1890s. The River Murray Waters Agreement in 1914, which took 13 years to negotiate, was the first of successive water sharing arrangements between the Basin states – South Australian, Victoria, New South Wales, Queensland and the Australian Capital Territory – and the Commonwealth. The Murray–Darling Basin Authority (MDBA) is the agency responsible for administering current intergovernmental agreements and legislation relating to the River Murray.
Weirs and dams were constructed along the River Murray throughout the 1900s to regulate water flow and service irrigation areas. Torrumbarry Weir (37 GL) downstream of Echuca was constructed in 1924; Hume Dam near Albury was constructed in 1928 and then expanded in 1961 (3,038 GL); and Yarrawonga Weir (118 GL) was constructed in 1939.
Lake Victoria (677 GL), located 60 km downstream of the confluence of the Murray and Darling rivers, in far-west New South Wales, was constructed in 1925 around natural wetlands. River flows from the central catchment are captured in Lake Victoria to facilitate and regulate flows to South Australia.
The Menindee Lakes storage was constructed on the Darling River in 1968, around ephemeral lakes and associated wetlands, with a capacity of 2,050 GL. Water from Menindee Lakes is used to manage and augment supplies to the lower Murray system.
Dartmouth Dam (3,096 GL) on the Mitta Mitta River was constructed in 1979 to augment water supplies to the Hume Dam and the Murray catchment, and enable further irrigation development.
The Snowy Mountains Hydro-electric Scheme impounded water from several rivers (Snowy, Eucumbene, upper Murrumbidgee and Tooma), which is redirected through tunnels to power generation plants. Water that passes through the Murray power stations through the Geehi Reservoir and Swampy Plain River adds an additional 900 GL of flow to the Murray system. Khancoban Pondage (21 GL), at the end of the Swampy Plain River, stores water from the hydro-electric scheme and subsequently releases it in response to demand for water for irrigation and urban use. Water from the Tooma Reservoir is transferred out of the Murray catchment to the Tumut River, in the Murrumbidgee catchment.
Along the length of the River Murray, water is also pumped directly from the river or diverted through small weirs to secure water for individual properties.
Water management in the Murray catchment is complex and managed by the MDBA. Water is released from Hume Dam, the Menindee Lakes and Lake Victoria to meet daily demand of urban centres (including Adelaide) and irrigators. Water for the lower Murray is preferentially released from the Menindee Lakes and Lake Victoria rather than upstream storages, to minimise river conveyance losses and minimise evaporation losses. Water is preferentially stored in Dartmouth Dam due to its low evaporation losses compared with other storages. Water is transferred from Dartmouth Dam to Hume Dam, as required, to meet forecast demand.
End-of-river flows are captured in Lake Alexandrina and Lake Albert and releases are made to the Southern Ocean through the operation of a series of barrages.
Water delivery for consumptive or environmental use has to take into account a number of constraints in the system. Daily transfer of water from Dartmouth Dam to Hume Dam is limited to around 10 GL per day, flows between Hume Dam and Lake Mulwala is limited to 25 GL per day, and flows downstream of Yarrawonga Weir through the Barmah Choke are limited to 10 GL per day, even with regulators in place, to prevent unseasonal flooding of the Barmah–Millewa Forest. The channel system of Murray Irrigation Limited, in the New South Wales Riverina, may be used to bypass this section of river and augment river flows to meet downstream water demand.
Travel time of water is another important water management consideration. It can take 4 weeks for water to travel between upper catchment storages and the lower Murray. This has a significant influence on system operations, especially when management decisions need to be made well in advance of the range of meteorological forecasts.
Environmental importance
The central part of the River Murray catchment contains floodplain forests that are environments of national and international importance. The forests represent the largest system of tree-dominated wetlands in southern Australia and contain unique examples of floodplain lakes, meadows and reed swamps, and include the Barmah Forest, the Millewa Forest, Gunbower Forest, and Koondrook and Perricoota forests.
The floodplain and wetland habitats of the Murray and its tributary and distributary rivers, support diverse habitats for a range of land and water plants and animals. The flood-dependent forests are dominated by river red gum and black box, and in some areas lignum. Within the forests are complex networks of wetlands, some of which support locally and nationally significant wetland plants, such as moira grass, tall spike rush and common nardoo.
The rivers in the central Murray region are important habitat for native fish. Historically, the waterways have had a high diversity of native fish species and were a major source for Murray cod, but native fish diversity and health across the region is declining, which is important not only from an ecosystem perspective, but also for recreational fishing and tourism. There are also significant but declining populations of other threatened and vulnerable fish species including silver perch, rainbow fish and southern pygmy perch.
Waterholes in the region provide a critical drought refuge for native fish species and, consequently, contribute significantly to the recovery of native species both at the local and Basin scale when flows improve. Billabongs and side channels in the region are also used as refuge sites for larval or juvenile fish species. Some fish species, such as golden perch, depend on higher flows to access the floodplain to meet all of their life history requirements.
Wetlands and riverine vegetation in the region provide habitat for a range of colonial waterbirds, such as the eastern great egret and straw-necked ibis, as well as migratory species such as brolgas and Australasian bitterns. Bird species also benefit from the large corridors of remnant river red gum and black box woodlands that line many of the creeks and flood runners in the region. Some of the numerous threatened and vulnerable bird species recorded in the area include diamond firetail, superb parrot and bush stone curlew. The River Murray and its surrounding wetlands provides important habitat for many native frog, turtle and bat species. There is also considerable interaction between farm land and the natural environment.
Further down the catchment, south of Mildura, is the Ramsar-listed Hattah–Kulkyne Lakes. The lakes are an important cultural heritage site, and its well-preserved vegetation provides habitat for a wide range of birds, animals and reptiles. There has been 12 species of migratory birds listed under international agreements reported at the site.
The Sustainable Rivers Audit 2 (released in 2012) reported the overall ecosystem health of the central River Murray valley was poor. In this report, the central Murray region extends to the junction of the Murray and Darling rivers at Wentworth.
Flow regulation had severely affected species abundance and diversity of fish, with the health of the fish community being rated very poor. The macroinvertebrate community was also rated poor condition. Riverine vegetation was rated good condition in riparian and floodplain environments. The physical form of the river was rated moderate condition but elevated sediment loads since European settlement has resulted in sedimentation within the river channel and there was evidence of channel simplification. Flow seasonality and variability was rated poor in the valley, especially in the middle and lower zones of the valley, where river flows are impacted by seasonality of supply for urban centres and irrigation.
Water recovery
The Basin Plan specifies how much water is required to satisfactorily manage environmental sites and functions in the Murray–Darling Basin. 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 New South Wales Murray surface water SDL unit applies to the upper and central catchment area on the New South Wales side of the River Murray, from the headwaters of the Murray to its confluence of the Edward River near Swan Hill. For this unit, the baseline diversion level of surface water determined by the Basin Plan is 1,812 GL per year. The required local reduction in take, to achieve an environmentally sustainable level of diversion, is 262 GL per year.
The Victorian Murray surface water SDL unit applies to the upper and central catchment area on the Victorian side of the River Murray, from the headwaters of the Murray to its confluence of the Edward River near Swan Hill, as well as small areas along the Victorian side of the river near Robinvale and Mildura. For this unit, the baseline diversion level of surface water determined by the Basin Plan is 1,707 GL per year. The required local reduction in take, to achieve an environmentally sustainable level of diversion, is 253 GL per year.
In addition to the 'local reduction' for each surface water unit, a further 971 GL per year is to be recovered from all southern Basin catchments (the southern zone 'shared reduction') to meet the needs of the whole Murray system.
Groundwater extractions and/or entitlements determined by the Basin Plan mostly matched the sustainable diversion limits set for the groundwater units in the Murray Alluvium and Goulburn–Murray groundwater water resource plan areas, in New South Wales and Victoria, respectively. Extraction from aquifers in the upper catchment was generally below the sustainable diversion level determined by the Basin Plan. For locally-specific detail of required reductions in water use, water users should consult regional water sharing plans developed by state government water departments.
Further information on water recovery in the Murray–Darling Basin, which includes an interactive map with catchment-specific information, is available at water recovery progress.
The Basin Plan allows for adjustments to SDLs if new works or changes in river operation and management rules increase the quantity of water available to be extracted; or efficiency measures through infrastructure works and upgrades reduce the quantity of water required in a delivery system.
The use of environmental water in a specific catchment or region will vary from year-to-year. The MDBA has produced 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 Office or the state government environmental water manager (see table below).
Water management
The management of the 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 ensures 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 4 states and 1 territory, are managed cohesively and in the best interests of all water users of the Basin. Such programs include:
Useful links
