National water availability

How much surface water does Australia have?
How saline are Australia's surface water resources?
How much of Australia's surface water resource has been developed?
How much groundwater does Australia have?
How saline are Australia's groundwater resources?
How committed are Australia's water resources?
How committed are Australia's surface water resources?
How committed are Australia's groundwater resources?
How much water is traded or transferred?
Further information

How much surface water does Australia have?

Although Australia's average annual rainfall of 469 mm/year is not particularly low, only 12% of it runs off to collect in rivers. Australia has 447 large dams storing about 79,000 GL (GigaLitres) of water for mainly urban, irrigation and hydro-electric power users, and to provide flood mitigation. Australia also has several million farm-dams estimated to store 9% of the total water stored (Institution of Engineers, Australia).

Map of mean annual run-off from surface water management areas.

Mean annual run-off map (PDF - 769 KB)

How saline are Australia's surface water resources?

The salinity volume for surface water was based on the percentage of the divertible yield of the resource.

States provided an estimate of the percentage of the divertable resource that fall into each salinity category. To produce the volume, the divertible yield for each management area was multiplied by this percentage for each salinity class.

Table: Surface water resource by salinity class based on mean annual flow
Region	<500 mg/l (GL/yr)	500 - 1500 mg/l (GL/yr)	1500- 5000 mg/l (GL/yr)	5000 - 14000 mg/l (GL/yr)	>14000 mg/l (GL/yr)	Total Divertible Yield (GL/yr)
Australia	150,552	820	2,976	183	1	26,347
Australian Capital Territory	255	no data	no data	no data	no data	128
New South Wales	9,641	64	2,317	no data	no data	no data
Northern Territory	111,827	no data	no data	no data	no data	no data
Queensland	no data	no data	no data	no data	no data	no data
South Australia	911	14	40	3	1	1,071
Tasmania	6,696	no data	10	no data	no data	no data
Victoria	10,051	10	140	1	no data	10,200
Western Australia	11,174	733	471	180	0	14,948
Note: Salinity information was not supplied for Queensland.

How much of Australia's surface water resource has been developed?

Water storage in Australia in this assessment was estimated to be 74,126 GL in 1996/97.

In the south-eastern (mainland) States of Australia, as surface water systems approach or are at extraction limits, water use efficiency, recycling, trading and pricing are increasingly becoming priorities and provide opportunities for development. The State and Territory water management agencies continue to consider water use efficiency and optimisation strategies within existing infrastructure (eg. water supply efficiency, precision irrigation and scheduling, water recycling, trading and pricing) as part of water resource development planning.

Map of developed yield of surface water management areas.

Developed yield map (PDF - 768 KB)

Region	Total Storage Volume (GL)
Australia	74,127
Australian Capital Territory	256
New South Wales	25,551
Northern Territory	274
Queensland	18,172
South Australia	2,724
Tasmania	52
Victoria	15,702
Western Australia	11,375

Divertible and Developed yield

The physical capacity to extract water from a river is referred to as developed yield. Developed yield is the average annual volume of water that can be diverted for use with existing infrastructure. This measure does not take into account environmental water requirements. Divertible yield is the average annual volume of water that could be diverted with existing infrastructure and all potential infrastructure (within technical and economic limits) under an ultimate development scenario. This measure takes no account of environmental water requirements.

Region	Current Developed Yield (GL/yr)	Divertible Yield (GL/yr)	Developed Yield: Divertible Yield (%)
Australia	11,562	26,347	43.88
Australian Capital Territory	86	128	66.82
New South Wales	no data	no data	no data
Northern Territory	no data	no data	no data
Queensland	no data	no data	no data
South Australia	751	1,072	70.08
Tasmania	3,543	no data	no data
Victoria	6,327	10,200	62.02
Western Australia	857	14,949	5.73
Please note: The volume of divertible yield is not reported for States and Territories that have an incomplete data set.

How much groundwater does Australia have?

Australia has 25,780 GL of groundwater suitable for potable, stock and domestic use, and irrigated agriculture that can be extracted sustainably each year of which 2,489 GL is used.

Map of Yield of groundwater provinces.

Developed yield of groundwater provinces map (PDF - 684 KB)

How saline are Australia's groundwater resources?

Australia's groundwater systems can be naturally saline. Some 70% of Australia's sustainable supply of groundwater is suitable for drinking and/or most agricultural uses. However only about 20% of this resource is current used. Location, cost and demand are also important factors in determining the development of water resources.

Chart of Australia's groundwater sustaiable yeild by salinity class

Table: Groundwater resource by salinity class based on estimates of sustainable yield
Region	<500 mg/l (GL/yr)	500 - 1500 mg/l (GL/yr)	1500- 5000 mg/l (GL/yr)	5000 - 14000 mg/l (GL/yr)	>14000 mg/l (GL/yr)
Australia	10,217	8,094	2,670	3,208	1,511
Australian Capital Territory	103	no data	no data	no data	no data
New South Wales	554	4,301	168	790	486
Northern Territory	5,798	187	325	142	6
Queensland	1,423	967	75	129	26
South Australia	no data	290	709	103	21
Tasmania	1,586	767	1	179	no data
Victoria	243	422	245	368	208
Western Australia	514	1,163	1,151	1,500	767

The salinity of water influences how it can be used - location, cost and demand determines whether it will be used. The table below provides a general guide:

Table: End use of water by salinity range
Class (Total dissolved solids of applied water)	Vegetables	Crops	Livestock	Other Uses*
A (0-500)	All	All	>All (Poultry, Dairy, Beef, Pigs, Horses)	Maintenance of ecosystems, Potable water supply, potable mineral water supply, parks & gardens, industrial water use, primary contact recreation,Buildings and structures.
B (501-1000)	Orchards, Grapes, Veg, Olives, Tomatoes, Broccoli	Oats, Wheat, Ryegrass, Millet, Clover, Lucerne, Beans, Barley, Cotton, Canola, Sunflower, Sugar Cane, Corn, Rice	All	As per Category A
C (1001-1500)	Orchards, Grapes, Veg, Olives, Tomatoes, Broccoli	Oats, Wheat, Ryegrass, Millet, Clover, Lucerne, Beans, Barley, Cotton, Canola, Sunflower, Sugar Cane, Corn	All	All except potable water supplies
D (1501-3000) ^	Orchards, Grapes, Veg, Olives, Tomatoes, Broccoli	Wheat, Ryegrass, Millet, Barley, Cotton, Canola, Sunflower	All	As per Category C
E (3001-5000) ^	-	Barley, Cotton, Canola	Dairy, Beef, Pigs, Horses	Ecosystems, Stock, Industrial, Primary Contact Recreation and Buildings and Structures.
F (5001-14000)	-	-	-	As per category E
G (> 14000)	-	-	-	Ecosystems, Industrial, Buildings and Structures.
* These uses are the beneficial uses listed in the Victorian Groundwater SEPP. ^ Towards the latter categories, there will be some reduction in crop yield, but this depends on the amount of water applied, the soil salinity, and the amount of flushing that the root zone gets. The soil salinity for the respective crops given above, is generally 50% higher than the water salinity tolerance.

How committed are Australia's water resources?

The determination of water allocation and use regimes, to achieve sustainability goals, requires consideration of a complex set of biophysical interactions in the context of a range of societal and economic demands. Integrated concepts of sustainable flow regimes and sustainable yield were adopted for this assessment in order to:

provide a comparable analysis across Australia's water resources
identify priority areas for further investigation or management action
communicate Australia's progress towards sustainable water resource management in an easily understood manner

A technical review of methods for establishing environmental water provisions was undertaken as part of the Audit's assessment. The National Water Resource Assessment Technical Report summarises State and Territory methods and progress towards sustainable water management.

This water resource assessment reports on sustainability of water management for surface water management areas and groundwater management units, and compares the nominated sustainable measure to allocation, current use, and the degree of infrastructure development for 325 surface water systems and 538 groundwater management areas.

The setting of a sustainable flow regime involves a trade-off between the demands for maintaining in-situ values and demands for water extraction. This is made more complex in that the allocation under licence may differ from the actual use. Where use patterns exceed the nominated sustainable flow regime, that system is deemed to be over-utilised. Where water allocation pattern exceeds the nominated sustainable flow regime, there is a potential for over-utilisation. Both of these cases have been identified as part of the Audit's assessment.

Surface water

The working definition of sustainable water provision adopted by the Audit for surface water systems is:

The limit on potentially divertible water that will be allowed to be diverted from a resource after taking account of environmental values and making provision for environmental water needs.

Methods of estimation across the States and Territories vary. The concept of sustainable flow regimes includes allowance for the frequency of high, low and seasonal flow regime requirements of the in-stream, wetland and floodplain environmental 'users' and reliability of supply for extractive users. For simplicity, the Audit assessment expresses these concepts as a 'sustainable yield' (or sustainable water provision). Sustainable yield, in a surface water context, is a water supply function. It encapsulates concepts of volume and frequency of flow - underpinning reliability and security of supply to both the environment and consumptive users.

Groundwater

The working definition of sustainable yield adopted by the Audit for groundwater systems is:

The level of extraction measured over a specified planning timeframe that should not be exceeded to protect the higher value social, environmental and economic uses associated with the aquifer.

Within this definition it was generally agreed for the Audit assessment of groundwater development status by the State and Territory agencies that groundwater level and pressure should be maintained.

Update on progress in groundwater

In May 2000 the National Groundwater Committee (a working group of the Sustainable Land and Water Resource Management Committee) agreed on a definition of sustainable yield and has submitted it to the High Level Steering Group on Water for endorsement:

The groundwater extraction regime, measured over a specified planning timeframe, that allows acceptable levels of stress and protects the higher value uses that have a dependency on the water.

Considerable ongoing effort will be required to operationalise the concept and review its implementation. Nonetheless the States have used a broad range of approaches to calculate sustainable yield: the principal method being a percentage of the assessed rainfall (commonly between 1% and 5%) as being the recharge and all or the majority of the recharge being the sustainable yield. However, in many cases other hydrogeological criteria and approaches have been adopted to suit specific circumstances.

The agreed national definition acknowledges that 'storage depletion' may occur. The approach provides a requirement for intervention when extraction levels cause unacceptable impacts such as storage depletion. The extent to which this has been applied is not clear. Nonetheless considerable scope exists for widely differing approaches between the States, with the result that it is not easy to compare across Australia.

Categorisation

A four-class classification system was developed to provide a simple method to communicate the status of the use and allocation of Australia's water resources in relation to sustainable water management.

It is important to recognise that adequately quantifying a sustainable flow regime or sustainable yield and consequent operating rules is a complex matter. State, Territory and scientific agencies continue to develop and apply methods and measures for determining sustainable flow regimes and sustainable yields.

This categorisation provides a general guide only. Please refer to the State and Territory Overview and Technical reports for detail on the analysis methods used.

	Category	Development status
1	<30%	Low development
2	30 - 70%	Moderate development
3	70 - 100%	Highly developed
4	>100%	Overdeveloped

Development status is water use as a percentage of sustainable flow regime (surface water) and sustainable yield (groundwater).

Category 1 systems have no to low levels of resource use, direct management interventions and information requirement is low. For example, Victoria River (Northern Territory, SWMA) Burnie (Tasmania, GMU)

Category 2 systems are moderately developed, management and resource information requirement is moderate. For example, Mary River (South Australia, SWMA), Ti Tree (Northern Territory, GMU)

Category 3 systems are close to, or at, their extraction limit and require a high level of management inputs. Resource information and monitoring is vital for these systems. Development depends on putting in place appropriate water markets to move water to higher value use and to provide surplus for development or the environment through efficiency gains. For example, Category 3: Pioneer (Queensland, SWMA), Woongarra (Queensland, GMU), Category 3*: All New South Wales SWMAs in the Murray Darling Basin subject to the MDBMC Cap

Category 4 systems are over-committed in water allocation and/or use-insufficient provision has been made for environmental and non-consumptive uses, management intervention and information requirements are substantial. For example, Wimmera-Avon Rivers (Victoria, SWMA), Neuarpur GSPA (Victoria, GMU)

The determination of the exact threshold of acceptable use tightens as the resource demand and pressure increases. This infers a ramping-up of both management and information needs. Consequently emphasis will be put on gathering more detailed data for Category 3 and 4 systems.

How committed are Australia's surface water resources?

84 of Australia's 325 surface water basins are currently close to or over-used in terms of meeting sustainable flow regimes. Currently 31 of Australia's 325 basins, have formal allocations for the environment. The benefits of these allocations to the environment will be assessed over time as the State and Territory water management agencies progressive implement the National Water Reform Framework.

Map of Surface water development status - 2000.

Surface water development status map (PDF - 658 KB)

Table: Number of basins and their surface water diversion (Div) and allocation (Alloc) development status
Region	Over		High		Medium		Low		Total withAvailable Information
Region	Div	Alloc	Div	Alloc	Div	Alloc	Div	Alloc	Div	Alloc
Australia	34	2	50	35	46	26	195	157	325	241
Australian Capital Territory	0	0	0	0	1	1	2	2	3	3
New South Wales	28		1		10		15		54	0
Northern Territory	0	0	0	0	1	1	39	39	40	40
Queensland	0	0	23	23	14	14	62	62	99	99
South Australia	5	1	1		6	1	22	2	34	4
Tasmania	0	0	7	7	2	2	10	10	19	19
Victoria	1	1	18	3	7	3	6	4	32	32
Western Australia	0	0	0	2	5	4	39	38	44	44

This categorisation provides a general guide only. Please refer to the State and Territory Overview and Technical reports for detail on the analysis methods used.

	Category	Development status
1	<30%	Low development
2	30 - 70%	Moderate development
3	70 - 100%	Highly developed
4	100%	Overdeveloped
* Water use as a percentage of sustainable flow regime (surface water) and sustainable yield (groundwater)

Chart of the proportion of groundwater management units and their use development status.

How committed are Australia's groundwater resources?

168 of Australia's 538 groundwater management units are close to or over-allocated, and 161 are over-used. Three of the groundwater management units across Australia have formal environmental allocations. Allocation decisions need to take account of groundwater dependent ecosystems. Examples of groundwater dependent ecosystems systems include the mound springs of the Great Artesian Basin, Swan coastal plain wetlands (Western Australia) and river-based flow systems of the Great Dividing Range. While detailed assessments have been undertaken for some systems, such as the Swan Coastal Plain wetlands, most assessments to date have been rudimentary. The State and Territory water management agencies will continue improve the definition, methods of assessment and determination of sustainable yield through the activities and initiatives of the National Groundwater Committee.

Map of Groundwater development status - 2000.

Table: Number of groundwater management units and their usage (Use) and allocation (Alloc) development status
Region	Over		High		Medium		Low		Total with Available Information
Region	Use	Alloc	Use	Alloc	Use	Alloc	Use	Alloc	Use	Alloc
Australia	55	79	110	85	93	63	275	282	534	534
Australian Capital Territory	0	0	0	0	0	0	3	3	3	3
New South Wales	6	21	7	6	15	6	25	20	53	53
Northern Territory	4	4	1	2	5	1	45	48	55	55
Queensland	29	35	28	9	26	7	19	52	102	103
South Australia	2	2	16	16	8	4	24	3	51	50
Tasmania	0	0	0	0	2	2	15	15	17	17
Victoria	12	15	16	10	11	17	40	37	79	79
Western Australia	2	2	42	42	26	26	104	104	174	174

This categorisation provides a general guide only. Please refer to the State and Territory Overview and Technical reports for detail on the analysis methods used.

Category	Development status
1	<30%	Low development
2	30 - 70%	Moderate development
3	70 - 100%	Highly developed
4	100%	Overdeveloped
* Water use as a percentage of sustainable flow regime (surface water) and sustainable yield (groundwater)

Chart of Proportaion of total groundwater management units and their use development status

How much water is traded or transferred?

One of the key elements of the National Water Reform Framework is water trading:

trading, including cross-border sales, of water allocations and entitlements, within the social, physical, and ecological constraints of catchments

Recognising that water is a finite resource, the States and Territories have developed water allocation systems where security and reliability are assigned to entitlement, trading is provided so water can be moved to high value uses and the choices of individuals are maximised.

Part of the decision-making framework to enable and facilitate water trading, changes in water allocation and definition of rights to water is the need for water use monitoring. Water use monitoring will assist decision-making and provide an opportunity over time to evaluate the effectiveness of allocation policies.

Further development of water allocation systems (to accommodate water trading) will reflect the principles and obligations of the National Water Reform Framework requiring that allocation, use and management of water resources be undertaken in a sustainable manner. Property rights to water have historically been variable and sometimes poorly defined and it is recognised that sustainable management is more likely to take place if this issue is resolved. With a clear definition of rights to water and monitoring of use, managers will be able to make informed decisions for water trading, marketplace value will be established, and allocation and trading efficiencies can be maximised.

For example, in the Murray-Darling Basin the Cap prevents diversions from increasing. Any water for additional development can be obtained by improving water use and supply efficiency or by purchasing water from existing users through water trading.

Region	Volume of /thade (GL/yr)	Number of /thansactions	Volume of inter-basin /thansfer (GL/yr)
Australia	457	1,531	4,567
Australian Capital Territory	0	0	0
New South Wales	305	1135	60
Northern Territory	0	0	0
Queensland	28	236	349
South Australia	7	0	4
Tasmania	0	0	0
Victoria	119	160	4,042
Western Australia	0	0	113
Note 1: Readers of this table should approach the relevant State agencies for confirmation of these totals. Note 2: The total volume of inter-basin transfer includes the transfer of water from the Mitta Mitta River SWMA (Victoria) to NSW of 814 GL/yr.

Australian Natural Resources Atlas

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National water availability

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How much surface water does Australia have?

How saline are Australia's surface water resources?