Desal plant should only be used when dams fall below 15pc, says academic

ENVIRONMENT groups say the desalination plant due to open in Sydney is unnecessary.

THE contentious Kurnell desalination plant in Sydney has been attacked as unnecessary, too expensive and damaging to the environment just weeks before it starts pumping billions of litres into the city's water supply.

Water experts, environmental groups and the NSW opposition have refocused their criticism of the $1.9 billion plant -- which will operate at full capacity for the first two years -- with calls for the plant to be mothballed after its proving period ends.

Stuart White, director of the Institute for Sustainable Futures at the University of Technology, Sydney, thinks the plant should not be used unless the dam levels supplying water to Sydney fall to 15 per cent of capacity.

Dam levels in the Sydney catchment area are currently at 51.4 per cent, while the main Warragamba dam is at 49.8 per cent.

"It's just not needed," Professor White says. "It's financially risky and an unnecessary asset."

The plant can produce up to 250 million litres a day and provide up to 15 per cent of the Sydney water supply.

For a two-year proving period it will be run at full capacity to check for defects regardless of dam levels. Sydney Water has conceded this will be reflected in higher water bills for customers.

Professor White claims this approach distorts the economic logic of supply and demand.

"It's a waste of money if the water's not needed. Desalination plants are an emergency drought-response measure . . . we'd be spending the operating cost of 70-80 cents per cubic metre (of water produced) for no reason."

The NSW Labor government has shrugged off the criticism, saying it is committed to securing the future of Sydney's water supply.

NSW Water Minister Phillip Costa told The Weekend Australian it was essential to test the facility, and said the plant would combat the challenge of population growth over the next 25-30 years. The Total Environment Centre has claimed the plant will unnecessarily contribute to greenhouse gases.

NSW opposition natural resource management spokeswoman Katrina Hodgkinson believes the plant will run at full capacity for a further two years but the government denies this.