Department of the Environment, Water, Heritage and the Arts, 2010
The Australian Government's actions to address water shortages around the country are shaped by the best available information on water availability and the way we use water.
Growing population, climate change, over-allocation of water and land use changes mean that there is now less water available than in the past.
The most recent Water Account by the Australian Bureau of Statistics was in 2004-05. In that year rainfall was 2,789,400 GL (billion litres) and run-off was 243,000 GL, which means that less than 10 per cent of rainfall was available for use. Just over 30 per cent of the available water in 2004-05 (79,784 GL) was extracted from the environment and used within the Australian economy, with about 75 per cent of this water returned to the environment following in-stream uses such as hydro-electric power generation.
Water consumption was 18,767 GL in 2004–05, a decrease of 14 per cent from 2000–01. The agriculture industry consumed the largest volume of water at around 12,000 GL, representing 65 per cent of water consumption in Australia in 2004–05. This was a four per cent decrease from 2000–01.
Households were the next highest consumer of water in 2004–05, accounting for 2,100 GL or 11 per cent of water consumption. The water supply, sewerage and drainage services industry was also a significant consumer of water, also accounting for 11 per cent of water consumption (mostly due to losses in distribution), followed by manufacturing with 589 GL (or 3 per cent).
Water markets allow water entitlements and allocations to be traded. The National Water Commission found that a total of 32,501 trades in water access entitlements and water allocations were recorded throughout Australia during the 2008–09 water year, involving 3,958 GL of water. Most of this trading took place in the Murray–Darling Basin.
Changes to the natural water systems of rivers have meant a decline in health for many river ecosystems. In 2008 the Sustainable Rivers Audit undertaken by the Murray–Darling Basin Commission found that 20 of 23 river valley ecosystems in the Basin were rated to be in poor or very poor health.