PETALING JAYA - More than 4.27 billion litres of treated water - enough to fill more than 1,700 Olympic-sized swimming pools or keep Perlis going for 53 days - are leaking out of the country's ageing pipe system every day.
Experts warn that more will be wasted unless drastic measures are taken.
If saved, that amount of water could ease stressed water supplies in the Klang Valley, as fears of a shortage and rationing loom dangerously.
According to the National Water Services Commission (SPAN), non-revenue water (NRW) accounted for 36.6 per cent of all water pumped out of treatment plants in 2013, or about 5.69 billion litres a day.
This was higher than 2012, which saw a 36.4 per cent NRW.
Of this amount, at least 75 per cent was due to problems like leaky asbestos-cement pipes and other infrastructure problems.
Association of Water and Energy Research (Awer) president S. Piarapakaran said that unless the pipes were fixed, more water would be lost even with state governments rushing to build treatment plants to meet a growing local demand.
"When the Langat 2 plant is completed (in 2017), it will pump 1,130 million litres a day (mld). If things don't change, 300mld will be just lost in the system," he told The Star.
While a number of states have seen their NRW levels fall in 2013, others such as Selangor saw more water lost.
Malaysian Water Association (MWA) president Syed Mohamad Adnan Alhabshi said more than RM20bil (S$8 billion) had to be spent to replace the country's 43,890km-long asbestos-cement pipes.
"You need to spend RM500,000 to change 1km of these pipes," he said, adding that state governments did not have the money.
He said water operators were unable to invest in stopping NRW as tariffs were low, giving them low revenue.
This was also reflected in SPAN's statistics - a deficit of RM429mil was incurred by all states combined last year.
MWA council member Hairi Basri said it was not easy to stop NRW as many of the problem pipes were underground.
MWA further estimated that if the country were to keep to SPAN's NRW target of 25 per cent today, the potential revenue operators could have made in 2013 was RM809.4mil.
SPAN executive director Mohd Ridhuan Ismail said combating NRW was more than just fixing or replacing leaky pipes.
Measures, he said, included mapping pipe networks, setting up district metering zones and a constant pressure management and maintenance of the system.
"It is not a one-off effort and the entire exercise requires huge investment," he told The Star.
He said state governments were hampered by low water tariffs and could not invest in NRW reduction measures, adding that human capital in this was also a challenge.
Mohd Ridhuan said many states had migrated their assets over to the Water Asset Management Com-pany (PAAB) to ensure their interests were protected.
He said states that had done so had managed to reduce their NRW substantially.
"SPAN believes that the remaining non-migrated states will be able to improve on their NRW once migrated," he said.