Australia publishes water and salinity inventories

When completed in around six months time, the atlas will be a ‘one-stop shop’ for data, maps on information on Australia’s natural resources, including soils, native vegetation, land use, and the economic return that is gained from the resources.

Each year, Australians use enough water to fill Sydney Harbour 48 times, says Roy Green, Chairman of the National Land and Water Resources Audit. Water use has increased by 65% since the early 1980s, said Green, adding that the greatest increases have occurred in Queensland and New South Wales. Irrigation for agriculture uses 75% of the water, with urban and industrial consumers using 20%, and domestic consumers and stock farmers using only 5%, said Green.

“Using the best available information provided by State and Territory agencies, the Audit shows that 26% of Australia’s surface water management areas are approaching or beyond sustainable extraction limits and that 34% of Australia’s groundwater management units are approaching or beyond sustainable extraction limits,” said Green.

The audit also provides the first consolidated statement on the extent and impacts of dryland salinity across Australia, and shows that approximately 43,000 km (27,000 miles) of the country’s rivers and 130 km (81 miles) of important wetlands are at risk from or already effected by dryland salinity. The problem could cover an area of 17 million hectares (42 million acres) in 50 years time, according to the survey.

“The audit identifies management options including restoring the water balance by changing farming practices, forestry or natural vegetation; protecting high value assets through engineering options such as pumping, evaporation or diversion; adapting to and using the saline environment – aquaculture and salt tolerant plants,” said Dr John Williams, Deputy Chief of CSIRO Land and Water.

“Once the water balance is changed and the salinity process underway, it is extremely difficult to show or reverse,” said Williams. “Prevention is a far better investment than trying to reverse the process. Northern Australia and some areas of temperate Australia can avoid dryland salinity.”