Desalination: a potential disaster

September 27, 2008

Salisbury Council, in the northern suburbs, is a world leader in stormwater harvesting. It is on track to produce 20 gigalitres of water per annum by 2010, just short of 10% of Adelaide's total water usage.

The council's director of city projects, Colin Pitman, addressed a 200-strong Save Our Gulf coalition meeting titled "Desalination — Solution or Disaster?" on September 24. He said: "I'm not going to argue for or against the desalination plant. I'm just putting the facts before you."

These include that if Adelaide recycled 60% of its stormwater, more than 100 gigalitres of water could be produced for $300 million. Conversely, the desalination plant planned for Port Stanvac in the south would produce 50 gigalitres of water per annum at a cost of $1.2 billion.

The Salisbury stormwater harvesting project uses wetlands to clean the water, which is then injected into the aquifer for storage. The water is then pumped back for use by industry, to water ovals, and for a variety of household uses such as flushing toilets, watering gardens and washing cars.

Residents of Mawson Lakes, a housing development supplied by the stormwater recycling project, have not been subject Adelaide's water restrictions.

As well as reducing reliance on the Murray River, stormwater harvesting benefits the environment of Gulf St Vincent by significantly reducing the amount of stormwater run-off into the ocean. The success of this project, which also produces significant income for Salisbury council, further exposes the irrationality of the state Labor government's push for the desalination option.

Dr Ian Dyson, a marine sedimentologist, explained the dangers the desalination plant posed to the rich marine life. The plant would discharge 50 gigalitres of brine into the gulf each year. Given the slow circulation of water in the gulf, this would likely create huge, hyper-saline sea lakes.

Dyson explained that the embryos of many species die at much higher rates as salinity levels increase, and the potential creation of high salinity "dead zones" would have catastrophic impacts on fisheries and exacerbate climate change through the release of methane.

Paul Dalby, a water industry consultant, said that desalination would raise the cost of water supply to households.

Peter Laffan, president of Save Our Gulf, explained: "We have to change how we do things to create a new, Earth-friendly civilisation. We have to learn from the traditional owners, the Kaurna, who understood how water travelled across the land.

"We also have to learn from new developments in science which show how we, in an urban environment, can live in greater harmony with the land."

Save Our Gulf are running a petition campaign and can be contacted at , or visit .

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