Council contractors have been pounding the pavements at Tinwald over the past two weeks, using special equipment to listen for water leaks.

The work is part of regular monitoring of Council’s drinking water network and helps find leaks in the reticulation pipes; sometimes leaks on private property are also identified.

Group Manager of Infrastructure and Open Spaces Neil McCann said the leak detectors used special acoustic equipment to listen to the water as it flowed in the pipes underground.

“The detector technicians use things like inground microphones, correlators, sound sticks, headphones, and some pretty complicated maths to pinpoint the likely spot of a leak. We then get in touch with our maintenance contractor ACL and arrange for the leaks to be dug out and fixed.”

The detection crew will be in action at Tinwald, Methven, Hinds and Rakaia over the next four weeks, listening to about 110km of pipes. Pipes vary in sizes and materials, and each produces different sounds. The crews use a mix of computer-generated images and sound audio to see the spikes that would indicate a leak along a length of pipe.

“We have to repair the leak, but long-term we need to work out when a pipe needs to be replaced,” Mr McCann said.  The location and number of leaks are also analysed by Council staff to assist with pipe renewal programmes.

Residents who live on streets where the detectors are working will see contractors open toby boxes to place sensors. This does not interfere with water supply to properties.

“Detecting leaks, big and small on our networks or private property, saves water and that saves money for ratepayers. Using less water means less needs to be pumped up from our deep wells and treated, and that’s the dollar saving,” he said.

“Plus it’s the right thing to do as part of sustainable water use.”

Private properties with suspected leaks will receive a letter from Council, encouraging them to fix the problem.