Murray

The Murray River forms most of Victoria’s border with New South Wales (NSW). Victoria shares the volume of water held in the major storages with NSW under the Murray-Darling Basin Agreement (MDBA).

For the purposes of these Accounts, the Murray basin refers to five non-contiguous regions, including the Upper Murray basin and four smaller areas in Victoria supplied from the Murray River downstream of Lake Hume. The Murray basin also includes flows in the Lower Broken Creek.

There are typically large volumes of water diverted from the Murray River for irrigation and environmental use. Irrigation diversions support significant agricultural production.

More information on water management and accounting is detailed in Water explained.

When compared to the previous year, in 2022-23:

• more rainfall was received, and catchment inflow was much higher, the highest volume received in 18 years
• storage levels were slightly lower at the end of the year
• there were more unregulated stream restrictions with a singular ban on licensed diversions
• high-reliability entitlements reached 100% allocation earlier
• low-reliability entitlements received an allocation for the second time since 2016-17
• less water was diverted for consumptive uses
• slightly less water was diverted from the basin for environmental uses.

2022 Flooding

Through Spring 2022, a series of low-pressure systems or surface troughs travelled over south-east Australia, bringing heavy rainfall and storms. The cumulative impact of these on catchments and waterways led to widespread flooding in several basins. High flows from the Mitta Mitta, Kiewa, Ovens and King, Broken, Edward, Goulburn, Campaspe and Loddon rivers joined the Murray River flows, and contributed to a slow progression of flood peaks along the Murray River.

Rainfall

In 2022-23, rainfall across the Murray basin was very much above the long-term average in most areas, and higher than the previous year. Rainfall was:

• the highest recorded in the reference period (1975 to 2023) in some parts of the upper Murray catchment
• very much above average in the western, central and most of the north-east region of the basin, around Mildura, Swan Hill, Cobram and Lake Dartmouth
• above average in the south of the north-east region around Omeo.

Figure 1 displays the rainfall received in 2022-23 compared to the long-term average (1975-2023).

Wastewater treatment plants

Water treated at wastewater treatment plants can be used to supplement water available in the basin. Water discharged to waterways from treatment plants is included as an inflow to the water balance.

Information on treatment plants is reported in the water supply local reports for the water corporation responsible for managing the plant.

In this basin, wastewater treatment plants are managed by Coliban Water, East Gippsland Water, Goulburn Valley Water, Lower Murray Water, and North East Water.

Compliance

Compliance against water entitlements is reported for this basin in 3 areas:

• entitlement issued: that the volume of entitlements issued in a basin does not exceed formal caps, and has not increased without appropriate approvals
• water taken: that the volume of water taken during the year does not exceed the volume considered to be available for consumptive and/or in-stream use during that year
• bulk entitlement provisions: that holders of entitlements do not breach any provisions that are documented in their bulk entitlement orders.

Note to increase in total entitlement volume:

• Water share volume increased by 4,266 ML (high-reliability) and 1,601 ML (low-reliability); all of this was issued for the Goulburn-Murray Water Connections Project and Goulburn-Murray Water Water Efficiency Project.
• Bulk entitlement volumes similarly changed due to these projects, with:
  • new entitlements to the 3 Melbourne retailers (total increase of 37,960 ML high-reliability and 20,630 ML low-reliability)
  • some adjustments to environmental entitlements (increase of 305 ML high-reliability and decrease of 2,663 ML low-reliability)
  • a corresponding decrease to loss entitlements.

These changes were commensurate with the irrigation modernisation works completed in line with the Water Act and Water Savings Protocol.

Note to compliance difficulties:

• Goulburn-Murray Water faced compliance difficulties due to extensive flooding from October to December 2022, affecting data quality for bulk entitlements. This impacted accurate tracking of tributary inflows in the Torrumbarry area, River Murray returns, and irrigation area losses.
• Lower Murray Water reported that the water taken at the Lake Cullulleraine off-take exceeded the daily rate listed of 120 ML per day in the bulk entitlement due to increased diversions licensed from the lake, however the volume taken did not exceed the total volume permitted in the bulk entitlement.

Environmental watering sites

Environmental watering sites in the Murray basin that depend on water for the environment include:

• the Barmah-Millewa Forest, Gunbower Forest, Hattah Lakes and Kerang and Lower Murray Wetlands, which are located along the Murray River and are internationally significant wetlands listed under the Ramsar Convention; except for the Kerang and Lower Murray Wetlands, these are also The Living Murray icon sites
• the Lindsay, Wallpolla and Mulcra islands (also The Living Murray icon sites), which rely on the freshwater inputs from the Murray River to function ecologically.

Environmental water reserve

In 2022-23, water for the environment in the Murray basin comprised:

• the Bulk Entitlement (River Murray - Flora and Fauna) Conversion Order 1999 - Flora and Fauna component, which includes 45,571 ML of high-reliability, 5,860 ML of low-reliability and 49,000 ML of unregulated entitlements held by the VEWH
• the Bulk Entitlement (River Murray - Flora and Fauna) Conversion Order 1999 - Living Murray, which includes 9,589 ML of high-reliability, 101,850 ML of low-reliability and 34,300 ML of unregulated entitlements held by the VEWH on behalf of the MDBA
• the Bulk Entitlement (River Murray - Flora and Fauna) Conversion Order 1999 - Barmah-Millewa Forest Environmental Water Allocation, a significant operational rule embedded in consumptive entitlements comprising 50,000 ML of high-reliability and 25,000 ML of lower security entitlements
• the Bulk Entitlement (River Murray - Flora and Fauna) Conversion Order 1999 - River Murray Increased Flows, comprising Victoria’s share of water recovered under the Snowy Water Initiative released from the Snowy Scheme to the River Murray, held by the VEWH
• the Environmental Entitlement (River Murray - NVIRP Stage 1) 2012, which includes allocated mitigation water for the purposes of watering specific environmental sites that have been identified through Goulburn-Murray Water Connections Project environmental approvals processes (1,207 ML of allocation in 2022-23)
• the Bulk Entitlement (River Murray - Snowy Environmental Reserve) Conversion Order 2004, comprising 29,794 ML of high-reliability entitlements, held by the VEWH
• 393,294 ML of high-reliability water shares and 43,025 ML of low-reliability water shares held for the environment
• water set aside for minimum flows released by the MDBA as a condition of the Murray-Darling Basin Agreement
• water set aside for the environment through flow-sharing arrangements set out in North East Water’s and East Gippsland Water’s bulk entitlements from unregulated rivers
• all other water in the basin not allocated for consumptive uses: this water also provides social, recreational and cultural benefits.

Environmental water use

A total of 273,764 ML of environmental water was sourced from the Murray basin in 2022-23. Of this, 95,441 ML was diverted off-stream. The remaining 178,324 ML was delivered in-stream in the Murray River.

A total of 482,221 ML of Victorian environmental water crossed the South Australian border. This delivery was supplied from environmental water entitlements in the Murray, Goulburn, Campaspe and Loddon systems.

Management of water in the Murray basin is undertaken by various parties.

The MDBA operates the Murray River on behalf of the Victorian, New South Wales and South Australian governments in accordance with the water-sharing arrangements set out in the Murray–Darling Basin Agreement. Under the agreement, Victoria shares the waters of the Murray River with New South Wales and South Australia.

Under normal conditions, Victoria is entitled to a 50% share of all flows upstream of Doctors Point near Albury–Wodonga (that is, flows to Hume and Dartmouth reservoirs and from the Kiewa River), a 50% share of inflows to the Menindee Lakes storage and all flows entering the Murray from the Ovens, Goulburn, Broken, Campaspe and Loddon rivers. Victoria is also required to supply half of South Australia's monthly entitlement flows from the water available to it.