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Our Natural Resources at a Glance - Water
Water
As Australia is a dry continent, irrigation is well established and is an important feature of the agricultural landscape. Widespread irrigation and extraction by other water uses has placed the natural ecosystems that rely on the nation's water resources under considerable pressure. The challenge for resource managers is to ensure balance between the use of water for production purposes and conservation of riverine environments
Drainage Basins of Australia
Percentage run off for each Basin
Water availability
- Australia has an average rainfall of only 469mm/year, with annual averages ranging from 127mm in south east South Australia to 3,163mm in north east Queensland.
- Evaporation rates are extremely high with only 12% of rainfall collecting in rivers, compared with a world average of 65%.
- Of all the inhabited continents, Australia has the least amount of water in its rivers. The rivers have more than twice the flow variation of those of Europe, second to southern Africa.
- Water storage capacity is over 4,000KL per person, the highest water storage capacity per capita in the world.
- There are 447 large dams supplying 79,000 GL (Gigalitres*) of water for irrigation, industrial, hydo-electricity and urban use.
- Estimated total water supply in 1996-97 was 80,363 GL.
Storage capacity (GL) in large dams to 1990 (IEA 1999)
Water use
- On average, 24,000 GL of Australia's water is used per year, or 1.31 ML/person/year.
- Household water use in the eastern capital cities averages from 300-400L/person/day.
- Approximately 75% of Australia's water is used in irrigated agriculture, 20% for urban and industrial uses and around 5% for other rural uses such as stock and domestic needs.
- Australia's water resources sustain 64 wetlands of international importance and more than 850 of national importance.
- About 80% of Australia's water is obtained from surface water and 20% from groundwater sources.
- Australia wide, 34 of 325 basins and 59 of 538 groundwater management areas are assessed as being highly or over-developed.
- Water usage increased by 60% (8,700 GL/yr) from 1983-84 to 1996-97.
- Irrigated agriculture use increased by 70% from 1983-84 to 1996-97. Irrigated agriculture uses only 0.4% of agricultural land and accounts for 25% of the gross value of agricultural production.
- Industrial use is not large and is falling as industries become more water efficient.
Water management
- In 1994 the Council of Australian Governments (COAG) announced a water reform agenda to ensure efficient and sustainable use of Australia's water resources. The framework emphasises environmental flows, water quality, integrated catchment management, water trading and pricing reform, viable and sustainable water use, and separation of responsibility for service delivery from regulation.
- A permanent 'cap' on diversions from the Murray-Darling Basin was confirmed in 1997, to ensure reliability of supply while protecting environmental flows.
- In August 2003 COAG announced the development of the National Water Initiative to improve security of water access entitlements, ensuring ecosystem health and that water is put to its best use and encouraging water conservation in cities.
- The southern Murray-Darling jurisdictions and the Australian Government also announced funding of $500 million to address over-allocation of water in the Basin.
Change in mean annual water use (GL)
| 1983-84 | 1996-97 |
% change in use
|
|
| Irrigation | 10,200 | 17,356 |
70
|
| Urban/Industrial | 3,060 | 4,673 |
53
|
| Rural (including rural domestic) | 1,340 | 1,238 |
-7
|
| Total | 14,600 | 23,267 |
59
|
Source: NLWRA, 2000
Groundwater
- Without groundwater - water stored underground in rock fractures and pores - much of inland Australia could not have been developed.
- The Great Artesian Basin (GAB) is Australia's biggest source of groundwater and extends under 1.7 million km2 (22%) of Australia including parts of South Australia, New South Wales, Queensland and the Northern Territory. The Basin ranges in depth from less than 100 metres at the edge to over 3km in places.
- The GAB contains 64.9 million GL of water, making it the world's largest artesian groundwater basin. Average groundwater flow is from 0.2 to 2.5 metres/year. It can take two million years for water to cross the Basin.
- Water from the Basin supports an extensive pastoral industry, significant mining and other industries. The GAB also supports nationally significant groundwater-dependent ecosystems where the water reaches the surface.
- There are over 3,300 flowing bores in the Basin, and another 1,400 bores have ceased to flow as a result of reduced pressures. In partnership with the States and farmers, the Australian Government has committed around $100 million to cap uncontrolled bores and replace wasteful open unlined bore drains, restoring around 8 metres of pressure to the GAB.
- In terms of area, 24% of groundwater management areas are being used at 70% to over 100% of sustainable yield.
- Australia uses about 4,100 GL/year of groundwater, of which 10% (440 GL) is supplied by the GAB.
Australian groundwater basins
Source: map modified from Lau, J.E., Commander, D.P. and Jacobson, G., 1987,
Hydrogeology of Australia. Bureau of Mineral Resources, Geology and Geophysics, Bulletin 227
...At a Glance
Australia - Our Natural Resources | Foreword | Overview | Water | Climate | Soils | Land Use | Vegetation | Social | Biodiversity | Pests | Government Initiatives | Data and Information sources | Acknowledgements
Last reviewed: 27 Mar 2007
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