Billions of litres of leaking water lost
More than 90 litres of water for every Perth household was lost from the Water Corporation's pipes and reservoirs every day before it could reach customers' meters, figures show.
After a three-year campaign in which the corporation has spent hundreds of thousands of dollars urging households to cut water use by 60 litres a day, the figures have exposed the utility's own waste.
The National Water Commission noted in its annual comparison of water providers that the corporation had the second highest rate for major utilities of "real water losses" (the difference between water produced and what passes through customers' meters).
Overall, real water losses for the corporation amounted to 21.6 billion litres in 2011-12 - the equivalent of almost half the Kwinana desalination plant's annual production.
The commission found the Water Corp had the lowest rate of water main breaks but said the amount of water lost from such incidents and other causes was high.
About 92 litres a day was lost on average for every service connection during the three years leading up to June 30 last year.
In comparison, Queensland Urban Utilities had the worst loss rate of 96 litres while the national average was 73 litres.
The figures come after the Water Corp abandoned efforts in recent years to stem the loss of supplies from bursts and leaks by reducing pressure in the network.
A trial project to cut pressure to about 3000 households in the southern Perth suburbs of Rossmoyne, Waterford and Shelley saved hundreds of millions of litres of water between 2007 and 2009.
But the corporation did not roll out the scheme further because many consumers did not like it and new desalination plants were alleviating Perth's water problems.
The corporation said real water losses were not a reliable measure to compare its performance.
Spokeswoman Clare Lugar noted the utility compared favourably with national and international equivalents and had taken steps to reduce losses, including leak detection technology.
