KUALA LUMPUR, March 27 -- Malaysians are being urged to immediately slash their shower times in half and stop washing their cars daily, according to the nation's top water regulator, as a prolonged heatwave pushes critical water sources like the Sungai Muda to dangerously low levels.

National Water Services Commission (SPAN) chairman Charles Santiago said these everyday habits - often overlooked - are collectively draining millions of litres of water at a time when supply is tightening.

"Go easy on car washing, gardening, and cut your shower time by 50 per cent," he told Malay Mail.

Santiago singled out car washing as a major source of water wastage, saying that some Malaysians even washed their vehicles every day.

"If you take one mi...