Water Supply and Sanitation in Australia - Water Resources and Water Use

Water Resources and Water Use

Australia is the driest inhabited continent on Earth, and among the world’s highest consumers of water. Amongst OECD nations Australia is ranked fourth-highest in water use per capita. Total water runoff in 2004–05 was estimated at 243 billion cubic meters (BCM) and total groundwater recharge was estimated at 49 BCM, giving a total inflow to Australia’s water resources of 292 BCM. Over 60 per cent of runoff occurred in northern Australia. Only 6 per cent of Australia’s runoff was in the Murray-Darling Basin, where 50 per cent of Australia’s water use occurs. Australia’s total large dam storage capacity was 84 BCM. While surface water is well known, groundwater resources are not well known. In 2004–05 the National Water Commission undertook water balance assessments for 51 priority geographic areas across Australia. Of these water management areas six were overused (consumptive use was greater than sustainable yield) and seventeen had a high level of consumptive use as a proportion of inflows (consumptive use greater than 30 per cent of inflows). Two water management areas (Great Artesian Basin and Mereenie Sandstone — Alice Springs) had consumptive use greater than total annual inflow. Total water use in Australia in 2004–05 was nearly 80 BCM, with about 75 per cent of this water returned to the environment following in-stream uses such as hydroelectric power generation. Consumptive use of water in the Australian economy in 2004–05 was 18.8 BCM (6.4 per cent of resources), with the agriculture sector the largest user (65 per cent), followed by household use (11 per cent). Residential water use declined from 243 liter/person/day in 2003 to 191 in 2007.

According to the Prime Minister's office, as the impact of climate change intensifies, Australia faces increasingly acute long-term water shortages with lower rainfall, rivers drying up and dam water levels falling. In most parts of Australia, surface water stored in reservoirs is the main source for municipal water supply, making water supply vulnerable to droughts; only a much smaller share comes from groundwater. Non-conventional water sources, such as seawater desalination, play an increasing role in Australia's water supply, with one desalination plant commissioned to supply Perth and others being built in Sydney, the Gold Coast, Melbourne, Adelaide, and another is planned to be built at Port Augusta.

The use of reclaimed water — the non-potable reuse of treated wastewater for irrigation of green spaces, golf courses, agricultural crops or industrial uses — is common and increasing in Australia. Among the 20 largest water utilities in Australia, the largest volume of recycled water supplied was by SA Water in Adelaide (25,047 ML or 29.6% of sewage collected), while the lowest volume of recycled water was by ACTEW in Canberra (2,104 ML or 7.4% of sewage collected).