Water leak detection

We actively monitor water loss in our water networks and undertake a targeted leak detection programme in a different Kāpiti settlement each year.

Our automated systems alert us immediately to drops in pressure in a network in the event of a major leak but slow leaks, caused by pipe failure, tree roots, service providers or construction activity, can be harder to identify.

Undetected leaks can waste huge volumes of water and cause extensive damage that is both costly and disruptive to repair when identified. In 2019/20, we estimated water loss in the Ōtaki water network could be as high as 293,000 m3 a year which is a loss of 233 litres per person per day.

Hunting for leaks in Ōtaki

In April 2021, we will undertake thermal imaging of our waterpipe network in Ōtaki as part of our leak detection programme.

In previous years, we have used traditional technologies to “listen” for leaks using specialist equipment. This can work well if the leaking water makes noise and the network contains copper or steel pipes but can be ineffective when monitoring Polybutylene pipes – the silent leakers - like those used in the Ōtaki network.

During summer and autumn, soil temperatures are warmer than the water carried through our water pipes and if a leak is present, it cools the surrounding area making thermal imaging a quick and effective way of scanning for issues.

To ensure we get a complete picture of the network, the thermal imaging camera is mounted to a drone which is flown down a corridor of a road. This must be done at night to get the best images.

This technology is considered cutting-edge in the management of water networks as it picks up leaks that other techniques miss and this is one of the first times it will be deployed in Kāpiti.

Protecting the privacy of our residents

The privacy of our residents is a top priority for us.

The camera is set to a thermal range that only picks up differences in ground and water temperatures. When set to this thermal range and travelling at height, people on the street are unidentifiable. The drone will not be surveying private property and the camera cannot see into houses or cars. Everything that’s not our pipe network appears as darkened objects in the images we capture.

This work will be undertaken by specialist contractor Cardno and the drone will be piloted by a trained operator who is certified for night time operations and complies with aviation safety protocols.

This work will be undertaken from early April, weather dependent.