AT least 30 per cent of Singapore's water needs will come from non-conventional sources by 2012.

Currently, the four NEWater plants produce some 50 million gallons of reclaimed water a day.

When a fifth plant now being built is completed in 2010, it will supply another 50 million gallons of reclaimed water daily, said Dr Tony Tan, chairman for National Research Foundation, on Tuesday.

Speaking at the Water Leaders' summit plenary forum, Dr Tan also told the delegates that Singapore is building a desalination plant using seawater reverse osmosis membrance technology which can supply up to 30 million gallons of drinking water per day.

'This brings Singapore closer to meeting the target of having non-conventional sources of water making up at least 30 per cent of Singapore's water needs by 2012,' he said.

Earlier on Tuesday morning, Prime Minister Lee Hsien Loong, speaking at the opening of the the World Cities Summit and the Singapore International Water Week at the Suntec City, said NEWater supplies 15 per cent of Singapore water needs today.

This will rise to 30 per cent in the next few years.

'With NEWater, we have closed the water loop by re-introducing reclaimed water back into the water supply, thus making maximum use of every single drop of water,' said Mr Lee.

'This wide-scale recycling is possible because Singapore has a fully sewered system, so that we can collect and treat all the wastewater generated. It also helps that a single agency, the Public Utilities Board, manages the entire water cycle in an integrated manner.'

He said the pace and scale of urbanisation today has intensified the challenge of providing safe, reliable, and affordable water.

'More and more cities and countries see access to water as a security concern and a potential trigger of conflict.

Global warming can aggravate this by altering existing water distribution patterns, intensifying droughts and disrupting the lives of millions, as is happening in Darfur,' said Mr Lee.