The premier of New South Wales state imposed the mandatory water restrictions on the city and its surrounding areas for the first time in nine years because of the country's worst drought on record and stubbornly rising domestic water use.

Premier Bob Carr said the indefinite curbs, to take effect October 1, would ban the use of sprinklers and watering systems and the hosing of all "hard surfaces", including vehicles, in the city of four million.

Violators will be fined 220 dollars (145 US) per incident, he said, announcing the crackdown at a Sydney area reservoir.

"The reason we're doing this is that the dam levels behind me are way lower than they should be at this time of year," Carr said.

The step came despite recent rains across much of eastern Australia that raised hopes that the country's worst dry spell was ending.

But Carr said the problem was more long-term and described his government's decision as a wake-up call to the real-life dangers of global climate change.

"This is the ninth consecutive year, speaking nationally, when rainfalls have been lower than average and average temperatures are climbing," he said.

"Those people who are sceptical about global warming ought to think again because this is the first very practical intimation of global warming being upon us," he said.

"Years from now, you might recall this announcement as the first time global warming affected our way of life," he said.

Dam levels within the Sydney Catchment Authority are currently at 60.5 percent of capacity, still above the 55-percent level when mandatory restrictions are normally applied.

But Carr said that with the southern summer approaching, it was necessary to act now on water curbs, which will effect metropolitan Sydney, the Blue Mountains to the west and the Illawarra Valley to the south.

"Basically there's three rules from now on," state Energy Minister Frank Sartor said.

"If you want to water your garden, use a hose; if you want to clean your footpath, use a broom; if you want to wash your car, use a bucket."

Sartor said the restrictions would remain in force until water storage levels in the Sydney area's 11 reservoirs reached 70 percent of capacity, and did not rule out even tougher measures if water consumption did not ease.

Compulsory water restrictions were in place for almost two years when they were last introduced in November 1994.

Environmentalists welcomed the water curbs and called for them to be made permanent.

"We must take this opportunity to make Sydney's water use more sustainable by introducing permanent restrictions just as Melbourne has recently done," said Leigh Martin of the Total Environment Center.

Melbourne, Australia's second biggest city, introduced water restrictions in October 2002 when its water reservoir levels fell below 55 percent.

SPACE.WIRE