Australian Natural Resources Atlas

Water resources - Allocation and Use - Western Australia

Location Map

Western Australia

How has Western Australia's water use changed since 1985?

Comparison between the 1985 and 2000 'snapshot' assessments is difficult. Factors include the time between assessments (more than 15 years); seasonality and variability of climate; significant potential for changes in land use; and fluctuations in domestic and global market demands.

Water Use, Climate and the Audit Baseline Year - 1996/97

The baseline year for the Audit is the 1996/97 agricultural year starting on the 1st April and ending on 31st of March. For water use the data was compiled for the period 1 July 1996 to 30 June 1997 (water calendar year). When it is necessary to collect information for more than one year, the data collected must cover that year or, alternatively, appropriately adjusted to provide a best estimate for that year.

For water use data States and Territories were requested to provide a 5 yearly average value based on the 1996/97 year. Use figures were adjusted in areas where, due to climatic conditions, the water use was not considered to be 'average'.

Climate in 1996/97

During 1996 there was a transition from the weak large-scale climate controls to a strong El Ni?o condition after March 1997. This resulted in a drying over a large part of southern and eastern Australia. From July until September 1996 Victoria had unusually cold and wet weather. The remainder of the southern half of Australia was also wet for three months. Significant areas in south-west Queensland, western and central New South Wales, South Australia, western Victoria, and southern Western Australia had rainfall totals within the highest 10% on record.

During the summer of 1996-97, there was a very active monsoonal season in the tropical zones in western Australia and the Northern Territory. However, this finished abruptly and early, as El Ni?o developed rapidly in autumn 1997. From October 1996 very dry conditions prevailed over most of Victoria, the grain belts of South Australia and north-east Tasmania. Areas of southern Victoria through to south-east South Australia had the driest October to June period on record.

May 1997 brought rain to southern Australia and average to above average rain to parts of Queensland. There was some relief to farmers from the dry and hot conditions over southern Australia in early 1997. In parts of southern Victoria and south-east South Australia the driest October to June period was reported. (ABS Water Account, 2000)

Climate in 1983/84 (Water Review 85)

Water use in any particular year is affected by weather conditions. For much of Australia, the period, July 1983 to June 1984, was equivalent to a normal year in which water use was about average. In south-east Australia, however, abnormal weather patterns were experienced. In general, rainfall totals throughout Victoria were high during the first half of the year but were lower than average in the second half. These weather conditions, along with a continuing sensitivity to water use following the 1982/83 drought, had a marked effect on water usage. Although the 1982/83 drought that affected most of Victoria was broken by above-average rains early in the year, water restrictions in many urban areas were not lifted until much later in the year. Urban water use was therefore less than average, due both to the heavy rains and to the continuance of water restrictions.

The above-average rains in the first half of 1983-84 greatly reduced irrigation demands, and by mid-season virtually unrestricted supplies of water were made available to farmers (for example, 200% of water rights in the Goulburn-Murray Irrigation District). The drier conditions in the latter half of the year somewhat compensated for this, but total usage for the year was generally far less than average.

Rural usage was also less than average, again due to the early wet conditions and sensitivity about excessive water use following the 1982-83 drought. (DPIE, 1987).

Map of change in total water since 1985

Note: The change in water use volume from 1985 to 1996 does not always reflect factors affecting consumption patterns and volumes such as population growth, industry or land-use change or operational improvements. The observed difference may partly be attributed to differences in the approach and assumptions used to estimate water use within the river basin.

Chart of Proportion of total water use by consumptive classes
Basin NameUse in 1983-84 (GL /yr)Use in 1996-97 (GL /yr)

% Change

WA701 659 -6
Albany Coast 64-34
Ashburton River 00no data
Avon River 121852
Blackwood River 161816
Busselton Coast 4798
Cape Leveque Coast 11-19
Collie River 57629
De Grey River 00no data
Denmark River 22-45
Donnelly River 43-23
Drysdale River 11-53
Esperance Coast 21-86
Fitzroy River (WA) 51-84
Fortescue River 07no data
Frankland River 22-23
Gascoyne River 00no data
Greenough River 42-49
Harvey River 7352-29
Isdell River 11-47
Keep River 1180
Kent River 21-53
King Edward River 11-37
Lennard River 11-17
Lyndon-Minilya Rivers 00no data
Moore-Hill Rivers 44-11
Murchison River 11-33
Murray River (WA) 152675
Ninghan 1140
Onslow Coast 00no data
Ord River 48271472
Pentecost River 1119
Port Hedland Coast 05no data
Preston River 411201
Prince Regent River 11-36
Shannon River 105-49
Swan Coast 41464,344
Warren River 108-14
Wooramel River 00no data
Yarra Yarra Lakes 11-3

Note: The total surface water use reported for each river basin does not include the water consumption of the eleven major cities. The data for cities and river basins are reported in the State totals.

How are the surface water resources used and allocated in Western Australia?

Chart of Proportion of surface water use by consumptive classes

Table: Surface water diversion and allocation 1996-97

Basin/SWMA NameAllocation (GL/yr)Diversion (GL/yr)Diversion: Allocation (%)
Western Australia8566590
Albany Coast 5477
Avon River 2298
Blackwood River 141498
Busselton Coast 77100
Cape Leveque Coast 11100
Collie River 896067
Denmark River 2178
Donnelly River 11216
Drysdale River 11100
Esperance Coast 1182
Fitzroy River (WA) 11100
Fortescue River 10763
Frankland River 2299
Greenough River 22100
Harvey River 936772
Isdell River 11100
Keep River (WA) 11100
Kent River 11100
King Edward River 11100
Lennard River 11100
Moore-Hill Rivers 44100
Murchison River 11100
Murray River (WA) 1288364
Ninghan 11100
Ord River (WA) 32127184
Pentecost River 11100
Port Hedland Coast 15530
Preston River 4480
Prince Regent River 11100
Salt Lake 11100
Shannon River 5597
Swan Coast 115116101
Warren River 32928
Yarra Yarra Lakes 11100

Note: Allocation is not based on 1999-2000 estimates; Diversion based on five-yearly average 1996-97.

Note: In the table above, the total surface water use reported for each river basin does not include the water consumption of the eleven major cities. The data for cities are reported in the State totals. The volume diverted is the total volume of the SWMA's surface water resources diverted for use both within the management area and for export to other management area.


The water use compilations indicate significant growth in water use since the nominal 1983/84 base year of Review85.

In Review85 the estimated gross water consumption in the State, from all sources, was 840 GL/Yr. In this Audit, figures for current use indicate that gross water consumption from all sources, including losses, amounts to 1800 GL/yr. Groundwater use has trebled since Review 85 and surface water use has increased by 40% mostly due to the Ord.

Significant factors, apart from normal economic growth, driving the increased use include mine dewatering (not adequately covered in Review85), significant step-function farm development in the Ord Irrigation Scheme and a widespread increase in self-supplied irrigation activity from surface and underground water sources in the South West Region.

Please note: The tables set out below detailing Level 1 and Level 2 water use categories. The sum of the Level 2 water use volumes will not necessarily equal the total Level 1 water use volumes. This is primarily due to lack of more detailed water use data. However, where Level 2 use = Level 1 use then blank cells in the table does not indicate water use unaccounted for in these categories. 

Map of total surface water use in 1996

Table: Surface water use in Western Australia 1996-97

Basin/SWMA NameIrrigation (GL/yr)Rural (GL/yr)Urban / Industrial (GL/yr)Total (GL/yr)In-situ (GL/yr)
Western Australia430232076591,715
Albany Coast 2224no data
Avon River 111718no data
Blackwood River 123418no data
Busselton Coast 6117no data
Cape Leveque Coast no data1no data1no data
Collie River 601362no data
Denmark River 1112no data
Donnelly River 2113no data
Drysdale River no data1no data1no data
Esperance Coast 1111no data
Fitzroy River (WA) no data1no data1no data
Fortescue River no datano data77no data
Frankland River 1112no data
Greenough River 2112no data
Harvey River 461652no data
Isdell River no data1no data1no data
Keep River (WA) no data1no data1no data
Kent River 11no data1no data
King Edward River no data1no data1no data
Lennard River no data1no data1no data
Moore-Hill Rivers 3114no data
Murchison River no data1no data1no data
Murray River (WA) 312326no data
Ninghan no data1no data1no data
Ord River (WA) 26318271no data
Pentecost River no data1no data1no data
Port Hedland Coast no datano data55no data
Preston River 111no data11no data
Prince Regent River no data1no data1no data
Salt Lake 111212no data
Shannon River 5115no data
Swan Coast 131134146no data
Warren River 8118no data
Yarra Yarra Lakes no data111no data
Map of surface water use for irrigation in 1996 Map of areas where surface water allocation is greater than sustainable yield

How are Western Australia's groundwater resources used and allocated?

The current total groundwater use in Western Australia is estimated as 1138 GL/yr. By comparison, Review85 estimated a statewide use of 376 GL/yr, although groundwater abstraction data for Review85 may in some cases have been incomplete.

About 25% of current groundwater use is for irrigation (approximately 300 GL/yr) with a dominant proportion (>90%) of that irrigation usage being on the Perth Coastal Plain. Sixty percent of the remaining irrigation use is in the Carnarvon Basin (Gascoyne).

Of the 840 GL/yr used statewide for urban, mining and industrial and over half is used within the Perth Basin, and nearly one third is used in the Yilgarn Division.

The most significant increases in water use since Review85 have occurred in the Perth, Yilgarn and Pilbara Divisions. In the Perth Region a significant increase of abstraction has occurred since Review85 for both urban and irrigation use. The urban, mining, industrial use reflects significant growth in both public water systems and self-supplied use. The irrigation use reflects the vigorously developing, and generally high value, irrigation industry of the Coastal Plain.

Most Groundwater Management Units are in the Category 1 level of utilisation reflecting a generally low level of allocative stress.

Only two of the State's Groundwater Management Units are in Category 4, these being the Murray Cockleshell Gully unit of the Perth Sedimentary Basin and the Collie Sedimentary Basin. Their combined sustainable yield is 11 GL/yr which is small in comparison with the State's estimated total sustainable yield of 6304 GL/yr and both resources are being actively managed with a strategy in place to reduce dependence on groundwater in order to bring extraction within the estimated sustainable limits.

There are a significant number of Category 3 Groundwater Management Units in the Perth region where utilisation is at or near sustainable limits. These include the intensively investigated superficial resources of the Gnangara and Jandakot mounds where environmental water provisions are established at reform standards. They also include the Leederville and Yarragadee confined aquifers which are considered to be fully allocated. Significant work is underway to improve the understanding of these aquifers and their sustainable limits.

In the Goldfields region, large volumes of hypersaline groundwater are extracted for mineral processing and mine de-watering. Extraction rates exceed direct recharge rates and reduction in paleochannel confined aquifer storage volume is accepted as the resource is hypersaline and does not appear to have any detrimental environmental impact. Pressure heads in most paleochannel aquifers appear to stabilise over time due to induced recharge from surrounding areas. Sustainable limits are set to the licensed allocation volumes.

In the Gascoyne region, the Carnarvon alluvial aquifers of the Gascoyne river are considered to be fully allocated. Controlled aquifer storage reductions within safe limits are allowed over the two or three year periods between river flow replenishment events.

The Albany GMU is also considered to be fully allocated.

Amongst these GMUs of high utilisation are a small number where there are issues associated with extractive pressure and a need for appropriate management. An example is in the Carnarvon Basin where a $4M program of capping flowing artesian bores is in progress. In addition, some sub-aquifer areas within these Category 2 or 3 GMUs may be in localised Category 4 situations with other sub-aquifers compensating by their lower allocation levels. Generally, these local situations are managed within the distributive capacity of the aquifer hydraulics. 

"GMU"=Groundwater Management Unit "UA"=Unallocated Area

Province Use in 1983-84 (GL /yr)Use in 1996-97 (GL /yr) % changeCurrent Alloc (GL/yr)Current Use : Alloc (%)GMU / UA
Western Australia784 1,138 46 no datano dataGMU
no datano dataUA
Albany-Fraser 1 no data111100GMU
no datano dataUA
Albany-Fraser 2 no data000no dataGMU
no datano dataUA
Amadeus 115121485GMU
20UA
Arunta 174576GMU
30UA
Banemall 0151515100GMU
no datano dataUA
Bonaparte 1322100GMU
10UA
Bremer 1 no data444100GMU
no datano dataUA
Bremer 2 no data555100GMU
no datano dataUA
Calyie-Mcfadden no data000no dataGMU
no datano dataUA
Canning no data171717100GMU
no datano dataUA
Capricorn 1 no data000no dataGMU
no datano dataUA
Capricorn 2 no data333100GMU
no datano dataUA
Capricorn 3 no data111100GMU
no datano dataUA
Capricorn 4 no data111100GMU
no datano dataUA
Carnarvon 1333333100GMU
no datano dataUA
Collie no data242424100GMU
no datano dataUA
Eucla 1100no dataGMU
0no dataUA
Halls Creek 1777100GMU
0no dataUA
Hamersley no data797979100GMU
no datano dataUA
Kimberley no data000no dataGMU
no datano dataUA
Leeuwin 1333100GMU
no datano dataUA
Marymia no data777100GMU
no datano dataUA
Musgrave 1110no dataGMU
10UA
Northampton 1333100GMU
no datano dataUA
Officer 1100no dataGMU
0no dataUA
Ord-Victoria 1700no dataGMU
60UA
Paterson no data000no dataGMU
no datano dataUA
Perth 1745745745100GMU
10UA
Pilbara no data999100GMU
no datano dataUA
Sylvania 0000no dataGMU
no datano dataUA
Tanami 0100no dataGMU
10UA
Yilgarn-Gold Fields 1136136136100GMU
no datano dataUA
Yilgarn-Murchison no data303030100GMU
no datano dataUA
Yilgarn-Southwest no data242424100GMU
no datano dataUA
Map of total groundwater use in 1996 by province Map of groundwater allocated volume Chart of total groundwater use by use class

Table: Groundwater use in Western Australia 1996-97

ProvinceIrrigation (GL/yr)Rural (GL/yr)Urban / industry (GL/yr)In-situ (GL/yr)Total (GL/yr)SY (GL/yr)
Western Australia28137 821 no data1,138 6,304
Albany-Fraser 1 no datano data11139
Albany-Fraser 2 000065
Amadeus 221215143
Arunta 4317159
Banemall no data1151566
Bonaparte 01331,264
Bremer 1 104434
Bremer 2 115535
Calyie-Mcfadden 000095
Canning 521017827
Capricorn 1 0no data0064
Capricorn 2 no data13319
Capricorn 3 no datano data1190
Capricorn 4 no data11164
Carnarvon 8161033245
Collie no datano data24249
Eucla 010194
Halls Creek no datano data77219
Hamersley no data17979314
Kimberley 000084
Leeuwin 3no datano data310
Marymia no data1777
Musgrave no data11164
Northampton 211317
Officer 0101183
Ord-Victoria 0627561
Paterson 000020
Perth 262144707451,911
Pilbara no data199159
Sylvania 00006
Tanami 0111153
Yilgarn-Gold Fields 11134136369
Yilgarn-Murchison 113030107
Yilgarn-Southwest 241924561
Map of groundwater use for irrigation in 1996 by groundwater province

Surface and groundwater interactions

There is no data for this state

Further information

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