With the warmer weather comes the annual surge in drink sales, and, for more and more people, the best thirst-quencher is an old-fashioned one: water.

This decade, Australians have increasingly embraced bottled water.

The national bottled water industry - that's spring, still and carbonated - is estimated to be worth at least $250 million a year, and growing by as much as 10 per cent a year. It's a remarkable trend in a country with some of the cleanest, most drinkable tap water in the world.

The chief executive of the International Bottled Water Association's Australian chapter, Mr Tony Gentile, believes demand will keep growing for at least another decade.

He says the average Australian drinks 30litres of bottled water a year, well behind the Swiss or Italians, who drink as much as 130 litres. ``These days people have learnt the European habit of drinking wine for taste and bottled water for thirst, and they have them at the same time."

He reckons water is being drunk at the expense of beer, coffee and tea because Australians are now more concerned about their health.

But a spokesman for Coca-Cola Amatil, which owns the Mount Franklin spring water brand, believes Australians are simply drinking more fluids. ``We don't think water is seen as a substitute for an alcohol drink, and soft-drinks are also growing in popularity," he said.

Regardless, bottled water - a healthy liquid with a sticker attached - has become trendy in the health, image and label conscious '90s.

Professor Bill Schroder, who specialises in marketing at Monash University, believes growing consumption is driven by consumers and not marketing. ``I also think there's a vague concern there about the health quality of tap water," he says.

Coca-Cola Amatil's spokesman says demand for bottled water is strongest in warmer regions such as Queensland, and not where tap water has a notoriously unpopular taste, such as South Australia.

The Australian Consumers Association's food policy officer, Mr Matt O'Neill, says the health benefits of drinking bottled water over tap water are minimal. ``Bottled water must be one of the cleverest gold-mine products, given that all you have to do is go to the tap and get it free," he says.