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The Barmah-Millewa Forest covers 66,000 ha and spans the New South Wales (NSW)– Victoria border between Tocumwal, Deniliquin and Echuca (Figure 5.2.1). It is listed under the (Ramsar) Convention on Wetlands of International Importance (the Ramsar Convention), the Australian Directory of Important Wetlands and is one of six Living Murray icon sites. The forest’s Victorian components are the Barmah National Park and part of the River Murray Reserve, covering 28,500 ha of forest and wetlands that support a vast range of significant plant and animal species.

The wetlands throughout the forest continue to provide a constant source of nutritional foods and significant fibres for the Yorta Yorta People. It is also evident that the resources in the landscape were utilized to manufacture canoes, shields and carrying devices.

Flooding in the Barmah-Millewa Forest depends on flows in the Murray River. A natural narrowing of the river (known as the Barmah choke) restricts flow and causes overbank flooding when flows below Yarrawonga Weir exceed the channel’s capacity. This restriction influences both the operation of Yarrawonga Weir and the upper limit of environmental flows that can be delivered to the forests.

Prior to river regulation for water supply, flooding would have regularly occurred with high flows from rainfall in winter and spring – helping to shape a rich and productive forest environment. Today, flooding in the forest is also influenced by system operation for water supply for users downstream in the Murray River, which can cause damage to the forest and banks of the river depending on the timing and volume of the flows.

The delivery of irrigation water during summer/autumn is managed to minimise unseasonal flooding of the forest. Regulators along the banks of the Murray River that control flow between the river and the forest remain closed during summer and autumn to restrict flow through low-lying flood runners. The delivery of water to Barmah Forest is also limited by a flow constraint below Yarrawonga Weir to minimise impacts to adjacent farming operations in NSW. The current constraint limits releases to a maximum of 18,000 ML per day between July and September (with potentially-affected landholder support) and to 15,000 ML per day for the rest of the year. To overcome this constraint, most environmental flows are shared between Barmah and Millewa forests to deliver water to low-lying wetlands in each forest at least every second year. It is currently not possible to achieve the desired flood depth and duration for floodplain marsh vegetation in both forests at the same time without larger natural flooding.

Water management at Barmah–Millewa Forest seeks to build on natural flow and the delivery of consumptive and operational water en route to optimise environmental outcomes when possible. As Barmah-Millewa Forest is located towards the upper reaches of the regulated portion of the Murray River, water for the environment that passes through the forest can often be used at sites further downstream as part of multi-site watering events.

Traditional Owners

System map

Environmental watering objectives in Barmah Forest

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Enable carbon and nutrient cycling between the floodplain and river through connectivity
Maintain or increase habitat for native fish and increase their population
Maintain or increase habitat available for frogs
Maintain or increase habitat available for turtles including the broad-shelled turtle
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Enhance the health of river red gum communities and aquatic vegetation in the wetlands and watercourses and on the floodplain

Promote the growth of floodplain marsh vegetation communities, with a particular focus on increasing the extent of Moira grass
Provide feeding and nesting habitat for the successful recruitment of colonial nesting waterbirds
Provide early-season flushing of the lower floodplain to reduce the risk of low-oxygen events in summer

Environmental values

The Barmah-Millewa Forest is the largest river red gum forest in Australia and the most intact freshwater floodplain system along the Murray River. The forest supports important floodplain vegetation communities including the threatened Moira grass plains and is a significant feeding and breeding site for waterbirds including bitterns, ibis, egrets, spoonbills and night herons. Significant populations of native fish, frogs and turtles also live in the forest’s waterways. Barmah Forest is known to support 74 plant and animal species protected under state and national legislation.

Recent conditions

The 2019–20 year was characterised by extremely dry conditions throughout spring, although two small natural flow events originating from the Ovens and Kiewa rivers caused low-level flooding in the forest in mid- and late winter. Carryover in the Murray system from 2018–19 was essential to enable watering early in the year; Victorian Murray allocations increased slowly as a result of the dry conditions during 2019–20.

Forest regulators were opened in July 2019 to allow a natural connection between the Murray River and the waterways in Barmah Forest. Flow increased above the channel’s capacity in August 2019 as a result of rainfall in upstream catchments. That event was followed by the delivery of the ‘southern spring flow’ — a planned environmental flow event for the Murray River between Lake Hume and the sea — which wetted low-lying parts of the Barmah Forest floodplain through September and October 2019. Environmental flows reduced in late October, and forest regulators were closed at the end of October 2019. Most floodplain habitats within the forest dried during summer and autumn. The main exception was a small section of the forest that re-flooded in January 2020 as a result of vandalism to a forest regulator.

Watering actions for Barmah Forest were mostly delivered as planned in 2019–20. Maintaining winter/spring connection between the river and the forest enabled carbon and nutrient exchange and improved food resources and habitat for fish, frogs, turtles and waterbirds. The low-level flooding supported wetland plant growth, but it ended too soon to stimulate some species to flower, due to insufficient water availability. A potential watering action that aimed to support colonial nesting waterbird breeding was not delivered, because significant natural breeding was not observed. Drying throughout the forest in summer/ autumn is important to maintain plant diversity and wetland productivity.

A prolonged, low-level, spring watering event in 2020–21 is desirable to allow more floodplain vegetation to flower, set seed and recruit. Waterbird breeding in Barmah Forest was at the lowest level in a decade in 2019–20 as a result of dry conditions. Providing flows to support a successful waterbird breeding event will be a priority in 2020–21. If conditions remain very dry, water for the environment will be mainly used to maintain critical drought refuges (such as waterholes in creek beds).

Traditional Owner cultural values and uses

“We are the First People of this place. We were here even before the Murray River flowed through Barmah.” — Uncle Des Morgan, Yorta Yorta Elder (Joint Management Plan for Barmah National Park, 2020).

Yorta Yorta are joint managers of Barmah National Park under a Traditional Owner Land Management Agreement with the State of Victoria. Goulburn Broken CMA worked with Yorta Yorta Nation Aboriginal Corporation during the environmental water planning process to source their feedback about planned watering actions. Yorta Yorta Traditional Owners have been involved in the development of longer-term management plans that have informed these watering actions.

Examples of Yorta Yorta cultural values and uses in Barmah Forest that are supported through environmental flow delivery include:

  • maintaining drought refuges, which protects turtles that are an important totemic species for the Yorta Yorta community
  • watering to support floodplain marsh vegetation, which includes important food and medicinal plants such as sneezeweed and basket sedge Yorta Yorta Nation Aboriginal Corporation contribute to Barmah Forest environmental watering planning, monitoring and management through employment as part of the Living Murray Program Indigenous Partnerships Program. This contribution is acknowledged in Table 1 with an icon.
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Watering planned and/or delivered in partnership with Traditional Owners to support Aboriginal cultural values and uses

Social, recreational and economic values and uses

In planning the potential watering actions in Table 1, Goulburn Broken CMA considered how environmental flows could support values and uses including:

  • water-based recreation (such as fishing)
  • riverside recreation and amenity (such as camping and birdwatching)
  • community events and tourism (such as providing access for boat tours)
  • socio-economic benefits (such as apiarists and irrigation diverters).

Scope of environmental watering

Table 1 Potential environmental watering actions and objectives for Barmah Forest

Potential environmental watering action

Functional watering objective

Environmental objective

Winter/spring low flow to various waterways in Barmah Forest (variable flow rates and duration during July to December)

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  • Provide flow in forest waterways to maintain habitat for native fish and turtles
  • Facilitate the movement of native fish between floodplain waterways and the river
  • Remove accumulated organic matter from waterways to cycle carbon to the river system and minimise the risk of hypoxic blackwater
Fish iconTurtle iconJigsaw iconWater drop icon 

Spring/summer freshes in the Murray River channel (one to three freshes that increase flow by at least 500 ML/day and maintain it for eight days during October to December)

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  • Trigger spawning of native fish species, primarily golden and silver perch

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Spring/summer/autumn freshes to Gulf and Boals creeks (100 ML/day for three to five days as required during November to April)

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  • Maintain critical drought-refuge areas in Barmah Forest to provide habitat for native fish and turtles
  • Flush drought-refuge pools to maintain water quality

Fish iconTurtle iconWater drop icon

Spring/summer/autumn low flow to floodplain waterways including Sandspit, Gulf, Big Woodcutter, Boals, Island and Punt Paddock Lagoon (200 ML/day for 30 to 60 days during November to April)

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  • Provide flows to replenish refuge areas and maintain water quality
  • Provide flows to replenish permanent waterways, to maintain fish and turtle populations
  • Maintain connectivity to the river
  • Remove accumulated organic matter, cycle carbon to the river system and minimise the risk of hypoxic blackwater

Fish iconTurtle iconJigsaw iconWater drop icon

Fill or top up Boals Deadwood, Harbours Lake, Reedy Lagoon and Top Island wetlands (200–400 ML/day for four and a half months during September to February)

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  • Provide a cue to initiate and/or maintain waterbird breeding
  • Maintain wetting duration and depth for growth of wetland vegetation

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Spring wetting of floodplain marshes (variable flow rates of 9,500–18,000 ML/day below Yarrawonga Weir for three months during September to December)

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  • Wet open plains for sufficient duration to allow the growth of floodplain marsh vegetation
  • Provide water to forest wetlands and low-lying floodplain areas to create foraging opportunities for waterbirds and increase available habitat for turtles, frogs and small-bodied native fish

Fish iconFrog iconTurtle iconPlant iconHeron icon

Autumn/winter low flow in the Murray River (1,800– 4,000 ML/day downstream of Yarrawonga during May to June)

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  • Increase water depth in the Murray River channel to provide habitat for large-bodied native fish in the Murray River and unregulated anabranches in Barmah–Millewa Forest

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1 Likely to target Millewa Forest in 2019–20, unless the Murray–Darling Basin Authority directs operational transfers via Barmah Forest.

Engagement

Table 2 shows the partners organisations with which Goulburn Broken CMA engaged when preparing the Barmah Forest seasonal watering proposal.

Seasonal watering proposals are informed by longer-term regional catchment strategies, regional waterway strategies, environmental flow studies, water management plans and other studies. These incorporate a range of environmental, cultural, social and economic perspectives and longerterm integrated catchment and waterway management
objectives. For further details, refer to the Goulburn Broken Regional Catchment Strategy and the Goulburn Broken Waterway Strategy.

Table 2 Partners engaged in developing the Barmah Forest seasonal watering proposal

Partner and stakeholder engagement
  • Goulburn Murray Landcare Network
  • Turtles Australia
  • Commonwealth Environmental Water Office
  • Trellys Fishing and Hunting
  • Field and Game
  • Yorta Yorta Nations Aboriginal Corporation
  • Goulburn-Murray Water
  • Parks Victoria
  • Murray Darling Basin Authority (the Living Murray program)

Page last updated: 24/07/20