"By cutting the amount of lost water in half, 150 million people could be supplied with treated water."
ADB estimates that 29 billion cubic meters of water - enough to fill more than 11 million Olympic-sized swimming pools - is lost each year in the region losing Asian water utilities more than 9 billion US dollars in revenue.
A report by Sri Lanka's finance ministry has said that non-revenue water at the state-run National Water Supply and Drainage Board in the Colombo city is about 31.3 percent in 2011 and it was 25.1 percent elsewhere.
The ADB says by examining good practices at eight of the best performing Asian water utilities it is possible to cut down waste.
While current unaccounted for water (UFW) levels in the region are as high as 60 percent, a level of less than 20 percent is a realizable goal, ADB says.Phnom Penh, had managed to bring its lost water rate down to just 6 percent in 2008.
The study has found that corporatization for better accountability; economic sustainability; unaccounted-for-water reduction and a holistic approach to manage water resources including water supply and wastewater management is needed.
Staff productivity, collaborative engagement amongst government, utilities and the society and a method to meet the needs of the urban poor was also needed.