City West Water, South East Water and Yarra Valley Water are using listening sticks, which can detect a leak from a water meter or hydrant, and ground microphones, which listen for leaks through the surface.

The precise locations of leaks are determined by a ‘leak correlator’. Once the leak is found, the water retailers send a maintenance crew to fix the problem.

Yarra Valley Water

Yarra Valley Water has invested over $A300,000 in its annual leak detection program. The company has combed around 2,600 km of its water reticulation system to identify and repair leaks, which will result in savings of approximately 700 million litres of water per year.

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Yarra Valley Water Managing Director Tony Kelly said that the leak detection program is part of the company’s wider strategy to reduce water losses in the system.

The strategy also involves a five-year, $A9 million Pressure Management Strategy to reduce excessive pressures in the network, and annual programs including a $A330,000 zone metering program to segment the network into smaller zones to target the leak detection program, a $A25 million Water Main Renewals Program, and a main to meter replacement program that will replace customers’ old pipe work from the main.

“This year we have almost tripled the number of kilometres of pipes assessed for leaks, and over the last two years we have identified around 1,700 leaks which has resulted in significant savings,” said Mr Kelly.

Yarra Valley’s leak detection program covers the identification and repair of leaks in areas reporting high water readings; targeted suburbs are identified using data from Yarra Valley Water’s zone metering program which uses dozens of in-ground flow meters.

A specialised team of ten work in pairs, using the listening sticks and ground microphones. This year Yarra Valley has trialled ‘Enigma’, a real time ‘leak correlator’ brought over from England that has an in-built computer and can locate the source of the leak immediately.

Other technology trialled from England this year included Leak Sizer, a digital ground microphone that can estimate the flow rate of the leak, once the location has been detected.

Managing Melbourne

Speaking on behalf of the three retailers, City West Water Managing Director Anne Barker said “Last summer, Melbourne experienced a high number of leaks, due to extremely dry conditions, causing pipes to crack or move out of alignment.”

The companies said that since the leak detection program started in 2003, they have checked over 23,000 km of water pipes and found and repaired almost 6,000 leaks.