Adelaide Water Supply

While the new water restrictions are a short term fix for South Australia, the long term supply of water is a puzzle, but not impossible according to a new study.

Adelaide will have sufficient water resources until at least 2050, even if its population were to double.

Don Bursill, former water scientist for the South Australian Water Corporation, made the prediction yesterday mindful of a state government plan to double the city's population over the next 44 years.

"Water won't hinder the growth of the city, simply because the use of water in supporting Adelaide is the highest economic use water can be put to," Professor Bursill said.

"We might have to pay more for water, but the capacity to pay is there," he said. "The technology is around to turn anything wet into drinking water if it's filtered through enough money, so an increased population can be accommodated."

Desalination was a valid option because it was becoming cheaper and the energy requirements were coming down.

"I don't think desalination is necessary yet, but the efficiency of the technology is improving and it will no doubt be on the agenda down the track."

Professor Bursill will be presenting his findings at an Urban Institute of Australia conference in Adelaide this week.

He said scare campaigns on the supply of water to the city were unnecessary. The political emphasis on reducing the reliance of the state on the Murray River was not grounded in facts.

"I'm not sure why in the past five years the public has been getting messages of impending doom in relation to our water supply -- nothing has really changed," he said. "Apart from the current outstanding drought, normal rainfalls and river flows suggest Adelaide can accommodate a higher population."

Professor Bursill said Adelaide used about 200 gigalitres of water a year, about half from the Murray River. This was less than 2 per cent of the average flow into South Australia. This is less than the statistical error that is normally found in measuring the flows in the river system.

"Although I am in favour of conservation and improving environmental flows in the river, I am not sure it is practical or would have any measurable impact to reduce the dependence on the River Murray."

Much of the water in the Murray evaporated before it hit the sea, he said, with 50 per cent disappearing in the large shallow lakes of Albert and Alexandrina next to the coast.

As well, more than half of Adelaide's water supply came directly from the Mount Lofty Range catchment area.

He said urban per capita consumption of water in South Australia had decreased over the past 15 years due to water conservation programs. At 19 per cent, Adelaide had one of the highest rates of recycling.

"We have the worst water resource, because of the dryness of the state, but the most reliable public water system because of the very good planning and investments that went into our water infrastructure last century," he said. "We are still living on those investments."

This is interesting, because it is not consistent with the message we hear from politicians.