Water in Australia: The Facts
- Australia is the highest user of water per capita in the world, despite being the driest inhabited continent
- Over a quarter of Australia's river systems are close to, or have exceeded, sustainable extraction limits, and two-thirds of water extracted is from these stressed systems. More groundwater is used than ever before.
- Median annual Murray River flows to the sea are now around one-fifth of what they were at Federation in 1901. The occasions when there is no flow at the River Murray mouth have increased from 1 year in 20 under natural conditions to 1 year in 2 under current conditions.
- 50 - 80% wetlands in MDB have been severely damaged or completely destroyed. The magnificent Coorong Lake near the Murray mouth has lost 90% of the migratory wader birds that once inhabited the estuary. In fact, there is only 11% of the natural estuary at the Murray Mouth left intact.
- Excessive regulation of flows and over extraction from rivers for irrigation has reached such levels that many floodplains are severely degraded. Indeed, the frequency of medium-sized floods at the South Australian border has fallen by 57%, robbing the internationally protected Chowilla Floodplain of life-sustaining flooding.
- Water use has increased from 1985 to 1996/7 by 65% and water is overused in some regions. Water extracted for irrigation has increased by 76% from 1985 to 1996/7.
- More than 80% of the average annual volume of water in the Murray is diverted for industry and domestic use - Irrigation accounts for 95% of this.
- There are 30 big dams and 3,500 weirs in the Murray-Darling Basin, and nearly three times the annual average flow in the Murray River is stored in dams and weirs.
- The threat of dryland salinity now extends across 6 million hectares of country, rising to an area more than twice the size of Tasmania by 2050 - nearly three times more - with up to 20,000 km of streams affected. (The cause of dryland salinity is the past and ongoing clearing of native vegetation - Australia clears more than any other developed nation and ranks fifth overall.)
- The Murray River supplies approx. 40% of Adelaide's drinking water supply. Within twenty years, on current trends, salinity levels will exceed World Health Organisation limits for safe drinking water two days out of every five on average.
- A half to a third of freshwater fish species native to the Murray-Darling Basin are threatened with extinction.
- Although it is difficult to determine, the frequency, size and persistence of harmful algal blooms in inland waters seems to have increased over the past 50 years. Algal blooms in dams cost farmers more than $30 million per year, and in rivers, storage and irrigation channels about $15 million per year.
- With the right incentives, market drivers and rules in place, it's been conservatively estimated that every public dollar invested would stimulate the private sector to invest $3.50 to generate both environmental and commercial outcomes.
Sources:
- Sustaining our natural systems and biodiversity" Prime Minister's Science, Engineering and Innovation Council, 2002
- The State of the Environment Australia 2001
- The Australian Dryland Salinity Assessment 2000
- The Australian Water Resources Assessment 2000
- "Repairing the Country: Leveraging Private Investment" Southcorp, Berri, Elders, ABN-AMRO, Macquarie Bank, ACF, CSIRO, 2001