Surface water

When compared to the previous year, in 2023-24:

• less water (total streamflow) was available (21,088,949 ML compared to 49,028,935 ML in 2022-23 when Victoria experienced significant flooding)
• there was less water in storages (levels in Victoria’s major storages were 82% in June 2024 compared to 92% in June 2023)
• a similarly high allocation was made to water share holders
• there were more restrictions on licensed diversions from unregulated streams (a peak of 80 stream sections restricted in March 2024 compared to 52 in March 2023)
• no desalinated water was produced (0 GL compared to 4.1 GL in 2022-23)
• a similar volume of surface water was diverted for consumptive uses (2,986,799 ML compared to 2,850,249 ML in 2022-23)
• more water was delivered for environmental purposes (933,031 ML compared to 612,279 ML in 2022-23)
• there was a higher volume of trade of allocation, less trade of water shares, and a reversal of net interstate trade (from net import to net export).

Table 1 reports on the total available water, total entitlements and total use (consumptive and environmental). In 2023-24, 3,919,830 ML of surface water was taken for consumptive and environmental purposes in Victoria (Table 1).

Total Victorian streamflows

Review of long-term surface water availability

For the 2023-24 Accounts, the estimates of long-term water availability, also known as long-term average inflows, were updated for the first time since the 2018-19 Accounts. The update has used an additional 5 years of data to better represent the current climate (1975 to 2024). Changes were made to all long-term average inflow estimates except for the Mallee, Millicent Coast, Bunyip and Snowy basins. The updated long-term average inflow has been applied to this year and the previous year’s volume on this page.

More detail on the update can be found in the method tab of Figure 1 and in Water Explained.

In 2023-24, the total annual streamflow volume for Victoria was 21,088,949 ML, 93% of the long-term average inflows received from 1975 to 2024 (22,767,600 ML). This was less than the volume in 2022-23, which was 49,028,935 ML, 215% of the long-term average, when there was significant flooding in Victoria.

In 2023-24:

• all river basins had lower annual streamflow volumes than the previous year
• there was considerable variability in the total streamflow (relative to the long-term average) per basin (Figure 2)
• the Corangamite basin received the lowest streamflow compared to the average, receiving 20% of the long-term average volume
• the East Gippsland basin received the highest streamflows compared to the average: 1,249,108 ML, equivalent to 140% of the long-term average volume.

Melbourne system inflows

The annual natural inflows to Melbourne’s harvesting reservoirs can be compared to 2 different baselines: the long-term average (from 1913-14 to 2022-23) of 574,624 ML, and the average of the last 30 years, which is lower at 484,427 ML.

In 2023-24, inflows were 507,651 ML, 105% of the 30-year average. This is less than the volume of inflows received the previous year (880,729 ML, 182% of the 30-year average).

Inflows in 2023-24 were below the long-term average. This is the first time in the past 5 years, but the 21^st time in the past 27 years, that inflows into storages have been below the long-term average.

Regional storage levels

In 2023-24, total regional storage levels:

• started the year at 93% in July 2023
• peaked at 94% in October 2023 (compared to 99% in December 2022)
• finished the year at 81% at end of June 2024.

Melbourne storage levels

In 2023-24, total Melbourne storage levels:

• started the year at 1,672 GL (92%) in July 2023
• reached a peak of 1,756 GL (97%) in February 2024 (compared to 98% in November 2022)
• finished the year at 1,568 GL (87%) at the end of June 2024.

Storages in major urban centres

The total volume of water stored in Victoria’s major reservoirs has historically been at its highest following winter and spring inflows. Storage levels at the end of October are traditionally a good indication of water availability for the remainder of that water year.

Figure 6 presents end-of-October storage levels as a percentage of storage capacity for Melbourne and selected major regional centres from October 2003 to October 2023.

At the end of October 2023, storages were between 77% and 98%:

• The regional storages were all between 77% and 98%, lower than the previous year when regional storages were all between 94% and 97%.
• Melbourne’s combined storage level was 96%, similar to the previous year when it was 98%.

Seasonal allocations

In 2023-24, seasonal allocations to high-reliability entitlements in all declared water systems reached 100%, the same as the previous year. In addition, all northern and southern systems received significant allocations to low-reliability entitlements, with 100% reached for all systems except for Goulburn and Loddon (77%).

By February 2024, all northern and southern systems had received seasonal allocations of 100% high-reliability water shares. By the end of the year, only the Wimmera Mallee Pipeline product, and low-reliability entitlements in the Goulburn and Murray did not reach 100% allocation.

Unregulated stream diversion restrictions

There were more unregulated stream sections with restrictions on licensed diversions in 2023-24 (Figure 7).

• The number of unregulated stream sections under restrictions and bans reached a peak of 80 in March 2024 compared to 52 in March 2023.
• There were 60 stream sections on restrictions at the end of 2023-24 compared to 43 at the end of 2022-23.

Desalinated water

Water produced by the Victorian Desalination Project is transferred into Cardinia Reservoir and combined with water sourced from upstream catchments and reservoirs, including O’Shannassy Reservoir, Upper Yarra Reservoir and Thomson Reservoir. The Victorian Desalination Plant can deliver up to 150 GL of water a year when operating at capacity.

No desalinated water was produced (0 GL) for 2023-24, compared to 4.1 GL produced in 2022-23.

Use by type

Table 4 shows the use of water in each basin. In some cases, these volumes differ slightly from the volumes of water taken under entitlements in each basin in Table 6. This is because Table 6 reports water taken under entitlements based on the source basin for each entitlement, while Table 4 reports water that was used within each basin. Some entitlements may source their water from one basin and then transfer it to be used in another basin. For example, in 2023-24, 1,305 ML was transferred from the Goulburn basin to supply urban use in the Yarra basin. In Table 6, the 1,305 ML is reported in the Goulburn basin as water taken under the entitlement, but in Table 4 the same volume is reported against the Yarra basin as water used.

In 2023-24, 3,919,830 ML of surface water was taken for consumptive and non-consumptive purposes (similar to the 3,462,528 ML in 2022-23).

Of this, 2,986,799 ML was taken for consumptive uses, about the same as the 2,850,249 ML taken in 2022-23. This includes water used for:

• irrigation: 2,155,499 ML (55% of total use)
• urban: 698,731 ML (18% of total use)
• small catchment dams: 89,632 ML (2% of total use)
• power generation: 42,937 ML (1% of total use).

In addition to the consumptive use, 933,031 ML was delivered for the environment under entitlements (24% of total use). This includes both in-stream and off-stream deliveries. There was an additional 18,366 ML of managed passing flows delivered in 2023-24. This was more than the 620,618 ML delivered in the previous year (612,279 ML under entitlements and 8,339 ML through managed passing flow deliveries).

Entitlement volumes

Entitlements provide the basis for how water is shared. The total volume of entitlements changes slightly each year as new entitlements are issued or existing entitlements are modified.

All basins in the state have a cap, which limits the volume of water that can be allocated. In catchments that have reached the cap and allocated all available water within the limit, no new entitlements are created unless water savings are made, and so there is no net increase in entitlement volume. This cap and trade system means that the only way for a water user to get more entitlement is to purchase it from someone selling unwanted or unused entitlement.

Most basins in Victoria have reached their cap, and so only a minor change in the total statewide volume of entitlements on issue is likely to occur annually.

Here is the list of Bulk and Environmental Entitlement holders as at 30 June 2024. Visit the Water Register website for up-to-date information on bulk entitlements.

In 2023-24, there was a net decrease in total entitlement volume of around 128 GL from 2022-23 (Table 5 and Figure 10). Most of this volume (124 GL) reflects a decrease in small catchment dam entitlement volume, which is represented by the estimated volume of use from small catchment dams for the water year. This approach is taken because not all small catchment dams are required to be licensed or registered under the Water Act 1989. The remaining net 4 GL decrease reflects smaller allowed entitlement volume changes in individual basins.

Changes to bulk and environmental entitlements 

Several amendments were made to bulk and environmental entitlements in 2023-24, a summary of the changes is as follows.

Amendments as part of water recovery projects in Northern Victoria

Further changes to entitlements occurred in 2023-24 as part of the Goulburn-Murray Water Water Efficiency Project and Lower Murray Water Sunraysia Water Efficiency Project. These investments modernised water delivery infrastructure in the Goulburn-Murray Irrigation District (GMID) and irrigation districts in Sunraysia. Following completion of on-ground works and an audit process, the consequent water-savings were allocated as entitlements. These changes during the 2023-24 year include:

• changes to reflect issuing of 10,387 ML of water shares to the environment for water savings in the Goulburn and Murray basins
• changes to reduce the corresponding loss allowances underwriting water recovery in the Murray and Goulburn basins.

In addition, 4,016 ML of new Mitigation Water environmental entitlements was issued to the Victorian Environmental Water Holder (VEWH) from water recovered from the Goulburn-Murray Water Connections Project. These entitlements replaced the Environmental Entitlement (Goulburn System - NVIRP Stage 1) 2012 and the Environmental Entitlement (River Murray - NVIRP Stage 1) 2012, which were repealed on 20 June 2024.

Other amendments

Other changes to bulk and environmental entitlements include:

• changes made to reflect the issue of 5,588 ML of water shares in the Thomson basin to Southern Rural Water for water savings achieved through the MID2030 phase 1A modernisation project
• transfer of 3,330 ML from Yarra Valley Water to Gippsland Water and resulting new Gippsland Water Greater Yarra System – Thomson River Pool bulk entitlement
• minor amendments to the Greater Yarra System – Thomson River Pool bulk entitlements to reflect the transfer of bulk entitlement from Yarra Valley Water to Gippsland Water and the new Gippsland Water Greater Yarra System
• amendment to Melbourne Water’s 4 Melbourne Headworks System bulk entitlements to reflect the transfer and new Gippsland Water bulk entitlement
• changes to Tarago and Bunyip Rivers Environmental Entitlement 2009 to enable VEWH to store its share of inflows in unused airspace in Tarago Reservoir, when its own capacity share (3,000 ML) is full
• further changes to formalise and reflect the new Melbourne Water Storage Manager appointment across the Goulburn System Greater Western Water, South East Water and Yarra Valley Water bulk entitlements
• issue of 4,016 ML of new Mitigation Water environmental entitlements to the VEWH from water recovered from the Goulburn-Murray Water Connections Project. These entitlements replaced the Environmental Entitlement (Goulburn System - NVIRP Stage 1) 2012 and the Environmental Entitlement (River Murray - NVIRP Stage 1) 2012 which were repealed on 20 June 2024

All changes to bulk entitlements are administered under Part 4, division 1 of the Act and require consultation and consideration of matters including the impact on current users and the environment.

Water available under entitlements

Table 6 represents the total volume of water that was available, and taken, under entitlements in each basin in 2023-24. The volumes of water taken for each basin may differ from Table 4, where the volumes represent the use of water in each basin. Some entitlements may source their water from one basin and then transfer it to be used in another basin. For example, in 2023-24, 565 ML was transferred from the Kiewa basin to supply Beechworth in the Ovens basin. In Table 6, the 565 ML is reported in the Kiewa basin as water taken under the entitlement, but in Table 4, the same volume is reported against the Ovens basin where the water was used.

The total available water volume in Table 6 is the sum of: opening carryover, allocation issued and the net trade of water (trade in less trade out), less water lost to spill. Rules for carryover, allocation and trade vary between entitlements and systems, and not all concepts are relevant for each basin.

Table 6 shows that in 2023-24:

• there was 7,160,908 ML of water available under entitlements (more than the 6,610,602 ML available in 2022-23)
• there was 3,864,056 ML of water taken under entitlements (more than the 3,340,785 ML taken in 2022-23).

Water leaving the basin is water that flows out of basins at their downstream ends. This includes all water flowing through the system, excluding diversions and losses. In terms of water for the environment, it includes managed environmental water delivered in-stream, obligations on consumptive entitlements (such as passing flows) and above cap water. This water flowing through the system provides environmental, social, recreational and cultural benefits.

Although water leaving the basin provides environmental benefits, the proportion of flows leaving Victorian river basins is not in itself a reliable indicator of river health. This is due to the complex interaction of ecological processes and the seasonal variability of streamflows.

In 2023-24, at a statewide scale, water leaving river basins was lower than the previous year. A total of 19,028,210 ML left river basins compared to 41,530,538 ML in 2022-23.

As a percentage of statewide total flows in basins, water leaving the basin was similar to the previous year, with 90% reaching basin outlets in 2023-24, compared to 85% the previous year.

Allocation trade

Water allocations can be traded subject to trade rules.

Allocation trade has been broken down into 3 categories:

1. Commercial trade indicates water transferred between water accounts at an agreed price.
2. Zero-priced trade indicates a movement of water to another account for zero dollars, excluding any trades involving environment water accounts. These trade applications may indicate a trade between accounts owned by the same person or related parties, or carryover parking return.
3. Environmental trade indicates trade between environmental water accounts, or zero-priced trades between private and environment water accounts.

In 2023-24, a total of 4,177,490 ML allocation was traded in Victoria, more than the total of 3,631,716 ML traded in 2022-23. 

The vast majority of allocation trade occurred in northern Victoria (4,167,368 ML), with a small volume traded in southern Victoria (10,122 ML) and no allocation traded in western Victoria. In 2023-24, the volume of priced trades in northern Victoria was the highest on record for the 2^nd year in a row: 1,444,995 ML. This is consistent with the trend of increasing allocation trade since 2007-08.

Environmental water holders use trade to move water across Victoria and between their accounts. Environmental trade made up 41% of the total volume traded in 2023-24, a similar proportion to the previous year. This includes water that was transferred to South Australia for delivery in the South Australian Murray system.

Trade in northern Victoria

A total of 2,722,373 ML of zero-priced trade (both non-environment and environmental trades) occurred in northern Victoria in 2023-24. A total of 1,444,995 ML of priced trade (commercial trades) occurred in northern Victoria in 2023-24 (Figure 12).

Trade between VIC, NSW and SA

Water trade between Victoria, New South Wales (NSW) and South Australia (SA) is permitted subject to trading rules. Interstate trade of water can occur due to allocation trade or tagged trade. Tagged trade is when water used in one trading zone is sourced from a different trading zone. Victoria has tended to be a net importer of water over most of the past decade, with exceptions in some years, including when conditions are unusually wet in Victoria or dry in NSW.

In net terms during 2023-24, excluding environmental trade (Figure 13):

• Victoria exported 14,093 ML of water to NSW, compared to 12,892 ML imported in the previous year
• Victoria exported 86,867 ML to SA, compared to 23,640 ML imported in the previous year
• there was 100,961 ML of interstate trade out of Victoria. This is a change from the net total of 36,533 ML into Victoria in the previous year.

Water share transfer

Trade of water shares represents a trade of ongoing annual water entitlements in declared systems. Most of the state’s regulated water systems have been declared.

From 2009-10 to 2011-12, large volumes of water shares were transferred to the Australian Government as part of buyback programs under the Basin Plan, resulting in much higher overall transfer volumes.

In 2023-24, water share transfer across Victoria included (Figure 14 and Table 9):

• 67,589 ML of high-reliability water shares transferring ownership; less than the previous year (89,101 ML).
• 33,898 ML of low-reliability water shares transferring ownership; less than the previous year (47,497 ML).

Unregulated surface water trade

Outside declared water systems, take and use licences allow water to be taken from either unregulated surface water systems or from groundwater, and to be used subject to the conditions defined in the licence.

Unlike allocation and water share trading, surface water take and use licence trading occurs more evenly across the state, with several trades in the west of the state. Trades as part of land transfers were the most common trade type.

In 2023-24, surface water take and use licence trading resulted in:

• 958 ML of unregulated surface water permanently traded (not as part of a land transfer), slightly more than the 869 ML permanently traded in the previous year
• 4,394 ML of unregulated surface water temporarily traded, more than the 3,144 ML temporarily traded in the previous year
• 10,620 ML of unregulated surface water traded as part of a land transfer. This was similar to the 11,634 ML traded as part of a land transfer in the previous year.