Snapshot
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Catchment area
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0.9% of the Murray–Darling Basin
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Contribution to Basin water
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10% of Murray inflow
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Annual stream flow
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900 GL (into Dartmouth Dam)
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River length
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204 km
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Major tributaries
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Big, Bundara and Cobungra rivers, Snowy, Little Snowy and Livingstone creeks
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Major towns/cities
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Dartmouth, Eskdale, Mitta Mitta
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Major water storages
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Dartmouth (3,856 GL)
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Key water users
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Urban water supply, stock and domestic, irrigation
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Summary
Rising on the high plains beneath Mount Bogong, the upper reaches and tributaries of the Mitta Mitta River drain through deeply dissected forests. The main channel of the Mitta Mitta forms at the confluence of Cobungra River and the Big River, and then flows northwards through near-pristine forest to Dartmouth Dam. The dam is the largest storage in the Basin and has the capacity to hold up to 40% of the water for the River Murray system. After Dartmouth Dam, the Mitta Mitta meanders north-west through a wide valley to the south arm of the Hume Dam.
The Mitta Mitta catchment is less than 1% of the area of the Murray–Darling Basin but it provides almost 10% of inflow to the River Murray system. Very little of the water generated in the catchment is used within the catchment.
The Mitta Mitta River is a declared heritage river area in its mountain reaches, from Glen Valley to Lake Dartmouth. The dam has strongly affected the hydrology of the lower river but there are good floodplain, billabong and wetland habitats downstream of Tallandoon on the lower reaches of the river.
There are small towns and farming communities in the Mitta Mitta catchment but about 70% of the region is steep forested hills and mountains. The dairy industry is a major source of income and employment in the region, and to a lesser extent, timber and beef production. Tourism is important to the region, with a focus on fishing, camping and 4-wheel driving.
The landscape and its water
The upper reaches of the Mitta Mitta River catchment are in the alpine landscape of the Great Dividing Range, east of Falls Creek. Close to the Kiewa River headwaters, the Mitta Mitta is formed by 4 tributaries, the Big, Bundara and Cobungra rivers, and Livingstone Creek.
The Big River is the main tributary, rising on the slopes of Mount Bogong and merging with the Cobungra River at Anglers Rest to form the Mitta Mitta River. The river heads north-east through the mountains, where alpine vegetation gives way to wet eucalypt forest. The Mitta Mitta is joined by the Livingstone Creek just west of Benambra, and then flows northwards to its confluence with the Morass Creek and smaller tributaries at the southern end of Dartmouth Dam.
The Dartmouth Dam signifies the transition from the upper to the lower Mitta Mitta River system. Below the dam wall, the river flows in a north-westerly direction through a rocky gorge and is joined by the Watchingorra Creek and then the Snowy Creek at the township of Mitta Mitta. At this point the mountains give way to foot hills and widening valleys, and more streams that meet the river as it continues its way Eskdale. Turning northwards, the Mitta Mitta meanders across a wider valley with extensively cleared floodplains and flows into the southern arm of the Hume Dam at Tallangatta, east of Wodonga.
Most of the Mitta Mitta basin has an average rainfall over 700 mm but increases with elevation to 2,400 mm at Mount Bogong. Elevation across the catchment ranges from 150 m at Hume Dam to 2,200 m at the alpine peaks in the south.
Surface water and groundwater systems in the catchment range from being highly connected to permanently disconnected. There are alluvial aquifers along the Mitta Mitta River, especially in its lower reaches and on the floodplain, where the ancestral Murray and Mitta Mitta rivers flowed. Most upland streams receive flow from fractured rock aquifers.
People, industry and water use
The Mitta Mitta River catchment and surrounding mountains, hills and valleys have been important for First Nations culture for at least 21,000 years. While some First Nations groups lived on the plains of the catchment throughout the year, many groups would travel to the mountains in spring and summer from much greater distances each year to feast on Bogong moths in the Australian Alps. These gatherings were also a time to perform ceremonies, share stories, and exchange knowledge and skills. The Mitta Mitta catchment is the traditional land of the Dhudhuroa and Yaitmathang nations.
European pastoralists arrived in the valley in 1835, and established cropping as the main industry. Alluvial gold was subsequently discovered in 1851, inflating the population to several hundred itinerant miners and helping to establish the township of Granite Flat. Dairying was introduced into the catchment in 1900, by which time mining had virtually ceased, and it remains the main agricultural industry of the area to this day. Beef production is also important.
There are no major urban centres in the Mitta Mitta valley, which has a population of only about 600 people. Beyond the valley, larger centres, such as Tallangatta with a population of about 1,000 and Albury–Wodonga with a population over 100,000, provide services to catchment residents.
The bulk of the land in the Mitta Mitta system is within the Alpine National Park, which is used for recreational and nature-based tourism, as well as conservation. The large area of freehold land around Omeo and Benambra is primarily agricultural and used for beef production. The lower Mitta Mitta valley is cleared for grazing, with the largest contributor to the local economy being the dairy industry, followed by beef farming.
Regulation of water
Following the droughts of the 1890s and dry periods in the 1900s, a decision was made by the Commonwealth and state governments to construct a water storage and irrigation scheme based on the River Murray. The Hume Dam was completed in 1934 east of Albury, impounding the Murray and Mitta Mitta rivers. Flow was regulated for water conservation, consumptive demands and environmental requirements. Hydro-electric power generation and flood mitigation were secondary functions of the 3,005 gigalitres (GL) capacity reservoir.
Upstream of the Mitta Mitta township, the waters of the Mitta Mitta River were impounded with the construction of Dartmouth Dam, which was completed in 1979. With a capacity of 3,856 GL, the dam is the largest in-stream water storage in the Basin, and with a wall of 180 m, it is the highest embankment of any dam in Australia. Operating as a secondary storage for the Hume Dam, Dartmouth Dam also helps regulate flood control and generate hydro-electricity.
Environmental importance
The lower reaches of the Mitta Mitta River provide habitats for high priority threatened native fish such as Macquarie perch, Murray cod, golden perch and flat-headed galaxias. Other high priority species found along the Mitta Mitta system include spotted tree frogs and the alpine spiny crayfish, in the upper Snowy Creek catchment.
Significant vegetation can be found along most of the river system in stands or remnant patches, providing an important habitat between waterways and larger areas of vegetation, including healthy stands of river red gum. Good riparian vegetation in the upper reaches of the Mitta Mitta provides habitats for animal species and native fish are present but with restricted diversity due to the water regulation.
The Mitta Mitta River upstream of Dartmouth Dam and the Big River are declared heritage rivers by the Victorian State Government. The Dartmouth Dam and the Mitta Mitta River are 2 of 8 nationally important wetlands in the region.
The Sustainable Rivers Audit 2 released in 2012 reported that the Mitta Mitta River ecosystem was in poor health. The fish community received the lowest score of the all the audited valleys, with most expected species absent and domination by alien species. The macroinvertebrate community was rated good, with high diversity especially in the upland zone, and with most fauna found in the upper reaches. Riverine vegetation was in moderate condition overall, however it was extremely poor in the slopes zone and good in the upland and montane zones. The physical form of the river was rated in good condition but there were changes to channel form end evidence of sedimentation. The hydrology of the Mitta Mitta system was also rated good, although there were significant changes in flow seasonality.
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.
In the Basin Plan, the Mitta Mitta catchment was included in the Victorian Murray surface water SDL unit, which 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 Murray–Darling Basin Authority (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
