· 6 min read · Taylor Plumbing
A water main leak rarely announces itself with a flood. More often it's a damp patch on the berm that never dries, a water bill that's crept up for no obvious reason, or a hissing sound near the toby when every tap in the house is off. Because the leak is usually underground and out of sight, it can run for weeks before anyone notices.
Christchurch's mix of older asbestos-cement and galvanised mains, plus ground movement from the earthquakes, means main leaks are common here. Knowing where your responsibility starts and stops saves an argument with the council and a wasted call-out.
Where the toby fits in
The toby is the boundary valve, usually sitting in a small box on the berm or front lawn near the street. It marks the legal line between council-owned pipe and your private pipe.
Everything from the toby back to the street main, including the connection itself, is the council's responsibility. Everything from the toby into your house, including the pipe under your lawn and driveway, is yours.
Signs of a water main leak
- A permanently wet or soft patch of lawn or berm, even in dry weather
- Water bills rising steadily with no change in household use
- The water meter dial still spinning when every tap and appliance is off
- Low pressure at the tap that wasn't there before
- A dip or slump forming in the driveway or lawn above the pipe run
Council pipe vs your pipe
If the leak is on the street side of the toby, it's a job for the Christchurch City Council (or Selwyn or Waimakariri District Council if you're outside the city). Report it to their faults line and they'll dispatch their own contractor.
If the leak is between the toby and your house, it's on you as the property owner. That's the section most homeowners don't think about until the bill or the wet patch shows up, and it's where we do most of our water main repair work.
How we find a private main leak
We start by isolating the toby and watching the meter to confirm the leak is on the property side. From there we use listening equipment to trace the sound of escaping water along the likely pipe route, narrowing the dig down to a metre or two rather than trenching the whole lawn.
On older sections with asbestos-cement or galvanised steel mains, a leak in one spot is often a sign the rest of the run is close behind it, so we'll talk you through repair versus a full replacement while we're there.
What repair or replacement involves
- Locating and exposing the leak with minimal digging
- Cutting out the damaged section and joining new MDPE or copper pipe
- Pressure-testing the repaired line before backfilling
- Reinstating lawn, paving or driveway as close to original as practical
- Full main replacement where the pipe is old and failing in multiple places
Ground movement and Christchurch mains
Post-earthquake ground settlement has left plenty of Canterbury properties with a main that's shifted, kinked or been put under tension at a joint. That shows up years later as a slow weep rather than a dramatic burst, so a leak on an older property is often worth investigating properly rather than patching and hoping.
Frequently asked questions
Need a hand with this?
Water main and supply line repairs across Christchurch and Selwyn. Toby to house, dig or trenchless.
See our Water Main Repairs service in ChristchurchMore guides
- Choosing a Plumber in Christchurch: What to Check Before You Book
- Finding a Hidden Water Leak in Your Christchurch Home
- Water Leak Repairs in Christchurch: Walls, Slabs and High Water Bills