Current diversion limits for the Basin

Water is used for a wide range of purposes across the Murray−Darling Basin. Water from rivers, lakes and underground is used by communities, farmers and industries.

A significant amount of water stays in the system or is ‘lost’ through evaporation and seepage. Evaporation rates in the Basin are high – 94% of rainfall in the Basin is used by plants or evaporates from land and water storages.

For many years, Basin state governments have regulated and monitored water diversions through their own compliance systems and under the Cap on Diversions. A new system of water limits has come into effect from 2019, which will replace the ‘Cap’ system. This next phase is an integral part of implementing the Basin Plan.

A new way of accounting for water

There are many forms of water use that will be fully accounted for under the new limits. This includes:

drinking and domestic water
industries
irrigated agriculture
water for the environment
water for stock
conveyance water
return flows
mining.

Water management in the Basin

Sustainable diversion limits an integral part of implementing the Basin Plan.

The sustainable diversion limits (SDLs) commenced on 1 July 2019.

SDLs are how much water, on average, can now be used in the Basin by towns and communities, farmers and industries.

Each area also has baseline diversion limits (BDLs).

BDLs are an estimate of water use limits and water used in the Basin, prior to the Basin Plan.

SDLs and BDLs are linked – any change to the BDL will then impact on the SDL.

Estimates of limits will improve as new information comes to hand.

Changes to the limits do not mean more water is available for use, this water is being used already or available for use under existing state laws.

Any updates will bring use into the new system, ensuring it can be monitored, and use does not grow over time.

Updates to water limits

Initial estimates for the limits were included under the Basin Plan in 2012. There are some diversions that have proven very difficult to accurately measure. This means these forms of water use are not fully accounted for in the rigorous way other water use is accounted for. This includes some of the water taken through floodplain harvesting and overland flows.

The baseline diversion limits need to consider the best available information and will adjust as improved information comes to hand. The BDLs are a representation of water use limits and water use before the Basin Plan, it’s important that this estimate is improved so past water use or limits are accurately reflected.

Governments are committed to obtaining more information on diversions, and continuously improving measurement and monitoring – this means the BDL estimates could be updated through the accreditation of water resource plans and into the future.

As part of plan development, the Basin state governments may choose to conduct further modelling, consultation, analysis and measurement to review the BDLs established in 2012 and if necessary, update these for each water resource plan.

Changes to the limits do not mean more water is available for use, this water is being used already or is available for use – it is just bringing this use into the new system, ensuring it can be monitored, and use does not grow over time beyond these limits.

Estimates of the limits are expected to change through to 2024, as new information comes to light and efficiency projects (under the Sustainable Diversion Limit Adjustment Mechanism) deliver water for the environment. It is expected some estimates will change as water resource plans are accredited.

Reasons for updated limits

Further work is being conducted to improve accounting of some diversions including floodplain harvesting, disconnected streams, and in the future, may include farm dams and plantations. These activities may be included in the estimate of the BDL to improve water accounting, but this will take some time and may need further adjustments over time.

Since 2012, we have an improved understanding of how state policies work in conjunction with the Basin Plan and the Water Act. For example, at the time of Basin Plan development, South Australia’s water allocation plans were being drafted. Their estimates have improved since the development of the Plan, which improves the BDL estimate.

When the Basin Plan was developed, there were some instances where there was no estimate on how much water was being used. We now have a better understanding of water use in these areas and an estimate has been determined, using relevant data and best available methods.

Compliance with limits

Usage will be measured and monitored, and the new limits will be enforced by the Inspector-General of Water Compliance (IGWC). The Murray–Darling Basin Authority (MDBA) will report on water use by Basin state governments at the end of the water year.

Basin state governments are the frontline of compliance and enforcement and are responsible for policing water use in their respective states. While in each state there are different compliance rules and enforcement approaches, the IGWC oversees compliance and enforcement across the Basin.

Read more about compliance and enforcement.

Estimate of Murray–Darling Basin baseline diversion limits and sustainable diversion limits

These are estimates that will apply for the 2021–22 water year, as calculated at 7 June 2022. Estimates are subject to change as new information becomes available.

SDL resource unit	BDL (2012)	Current BDL	Reason for BDL update	SDL (2012)	Current SDL	Reason for SDL update
NORTHERN BASIN
Queensland
Condamine–Balonne	978.3	1,019.0	New information available and Improved modelling	838.1	919.0	Northern Basin Review and SDL shared reduction reallocation
Moonie	84.2	92.0	New information available and Improved modelling	82.3	89.9	Northern Basin Review and SDL shared reduction reallocation
Nebine	31.2	20.9	New information available and Improved modelling	29.9	17.1	Northern Basin Review and SDL shared reduction reallocation
Paroo	9.9	11.8	New information available and Improved modelling	9.9	11.8	Northern Basin Review and SDL shared reduction reallocation
Queensland Border Rivers	320.1	377.6	New information available and Improved modelling	298.5	363.6	Northern Basin Review and SDL shared reduction reallocation
Warrego	127.7	75.6	New information available and Improved modelling	117.2	55.5	Northern Basin Review and SDL shared reduction reallocation
Queensland (Subtotal)	1,551.4	1,596.9		1,375.9	1,456.9
Northern New South Wales
Barwon Darling Watercourse	198.0	208.2		180.9	176.2	Northern Basin Review and SDL shared reduction reallocation
Gwydir	450.2	579.8		389.9	530.2	Northern Basin Review and SDL shared reduction reallocation
New South Wales Border Rivers	302.6	327.1		283.9	320.1	Northern Basin Review and SDL shared reduction reallocation
Intersecting Streams	114.0	133.1	New information available and Improved modelling	113.8	119.3	Northern Basin Review and SDL shared reduction reallocation
Namoi	508.3	510.3	New information available and Improved modelling	479.0	490.3	Northern Basin Review and SDL shared reduction reallocation
Macquarie–Castlereagh	734.3	691.4	New information available and Improved modelling	645.4	633.8	Northern Basin Review and SDL shared reduction reallocation
Northern New South Wales Subtotal	2,307.4	2,449.9		2,092.9	2,269.9
NORTHERN BASIN TOTAL	3,858.8	4,046.8		3,468.8	3,726.8
SOUTHERN BASIN
Southern New South Wales
Lower Darling	60.5	57.7	New information available and Improved modelling	45.8	35.4	SDL shared reduction reallocation and SDL adjustment amount
Murrumbidgee – New South Wales	2,501.1	2,661.6	New information available and Improved modelling	1,937.7	2,209.6	SDL shared reduction reallocation and SDL adjustment amount
New South Wales Murray	1,811.7	1,827.7	New information available and Improved modelling	1,341.8	1,512.3	SDL shared reduction reallocation and SDL adjustment amount
Southern New South Wales Subtotal	4,373.3	4,547.0		3,325.3	3,757.3
Australian Capital Territory
Australian Capital Territory	52.5	58.3		47.6	53.4	Other – Legislative changes

Victoria
Broken	56.2	49.3	New information available and improved modelling	54.6	49.0	SDL shared reduction reallocation and SDL adjustment amount
Campaspe	152.6	140.6	New information available and improved modelling	120.9	111.7	SDL shared reduction reallocation and SDL adjustment amount
Goulburn	1,689.4	1,651.2	New information available and improved modelling	1,153.0	1,278.0	SDL shared reduction reallocation and SDL adjustment amount
Kiewa	24.6	27.7	New information available and Improved modelling	23.3	27.7	SDL shared reduction reallocation and SDL adjustment amount
Loddon	178.6	139.7	New information available and improved modelling	155.8	127.7	SDL shared reduction reallocation and SDL adjustment amount
Ovens	83.4	85.8	New information available and Improved modelling	80.3	85.8	SDL shared reduction reallocation and SDL adjustment amount
Victorian Murray	1,707.1	1,718.0	New information available and improved modelling	1,251.7	1,319.8	SDL shared reduction reallocation and SDL adjustment amount
Victoria Subtotal	3,891.9	3,812.3		2,839.6	2,999.7
South Australia
Eastern Mount Lofty Ranges	28.3	28.3		26.4	28.3	SDL shared reduction reallocation
South Australian Murray	665.0	681.1	New information available and Improved modelling	483.1	542.2	SDL shared reduction reallocation and SDL adjustment amount
Marne Saunders	2.9	3.0	New information available and Improved modelling	2.9	3.0
South Australia Non-Prescribed Areas	3.5	55.2	New information available and Improved modelling	3.5	55.2
South Australia Subtotal	699.7	767.6		515.9	628.7
TOTAL SOUTHERN BASIN	9,017.4	9,185.2		6,728.4	7,439.1
Disconnected Systems
Lachlan	618.4	626.3	New information available and Improved modelling	570.4	578.3
Wimmera–Mallee	128.5	99.1	New information available and Improved modelling	105.5	76.1
TOTAL MURRAY–DARLING BASIN	13,623.1	13,957.4		10,873.1	11,820.3

Updated: 27 Oct 2022