Leak Detection in Paeroa

Paeroa sits on the Hauraki Plains where the Ohinemuri River meets the Waihou, a short distance inland from the Firth of Thames. It is an older town with established streets, a compact commercial centre and housing that mostly pre-dates modern plastic pipework, which means galvanised and asbestos-cement lines are still common under the sections.

The ground here is peaty and alluvial, soft and wet for much of the year. Pipes laid in it settle and shift, joints open up and leaks can travel some distance through the saturated soil before showing on the surface. The rivers are held in by flood-scheme stopbanks, and the water table is rarely far below the grass.

Hauraki District Council runs the town's water and wastewater. Beyond the town, dairy farms spread across the plains on long private water runs fed from bores and the council's rural supply, and those lines are a regular source of leak and locating work for us whenever we are through on a Hauraki trip.

Paeroa's housing is mostly pre-1970, so galvanised laterals and asbestos-cement mains dominate, with lead-jointed cast iron under the oldest streets near the Ohinemuri. In peat and soft alluvium that matters more than elsewhere: the ground settles, the pipe does not, and galvanised threads and AC joints are the first things to give. The water then drains into saturated ground, the lawn stays dry and the Hauraki District Council meter, read every six months, quietly climbs.

Copper from the 1960s does better, but its fittings corrode in wet peat. The small amount of post-2013 building is on MDPE, often cut into those old AC mains, and new plastic carries no dependable tracer wire. For locating, Paeroa's old metal pipe traces well from the toby but sits at odd depths where the ground has dropped around it, so the depth on a plan is rarely the depth in the ground, and we pothole with hydro-vac rather than trust it.