Watermains and water supply lines in Christchurch
The pipe running from your toby to the house does more to your water pressure than anything inside it. We install new mains and replace old, leaking and undersized ones.
What the main actually does
Your water main is the private supply line running from the council toby at the boundary to the house. Everything inside — every tap, the shower, the cylinder — is fed through it. If that pipe is old, undersized, partly blocked or leaking, no amount of work on the fixtures will fix the symptoms.
It is also the part nobody thinks about, because it is buried and it fails slowly. Pressure that has dropped off over years reads as normal until you compare it with a neighbour's.
What we do
- New mains. Supply lines for new houses, sleepouts and self-contained units, sized for what the building will actually draw.
- Replacement mains. Old galvanised steel and early alkathene runs replaced in modern pipe, usually along a new line rather than trying to reuse the old one.
- Upsizing. A main that was adequate for one bathroom and is now feeding three, or a long run to a back section that has never delivered proper flow.
- Leak repair. A supply line losing water underground — often showing up as a wet patch, a running toby, or a water bill that has climbed for no reason.
- Isolation and backflow valves. A proper isolating valve where the main enters the building, so the house can be shut down without going out to the toby in the dark.
Why Christchurch mains fail
Galvanised steel. A lot of older housing was plumbed in galvanised pipe. It corrodes from the inside, and the bore narrows over decades until the pipe is a fraction of its original size. Pressure falls away gradually, and discoloured water after the supply has been off is a classic sign.
Early alkathene. Black low-density polyethylene from the sixties and seventies goes brittle with age, and the compression joints of that era are a common failure point. A main that has been repaired twice is telling you something.
Ground movement. The earthquakes pulled joints apart and put strain on buried pipework right across the city. Some of that failed immediately; some of it has been weeping ever since.
Long runs. Hill properties and back sections often have a long haul from the toby, and length costs pressure. A main that is one size too small over forty metres behaves very differently from the same pipe over ten.
Where the main stops being yours. As a rule, the supply line from the toby to your building is the property owner's, and that is the part we work on. The connection to the council main, the toby itself and everything on the street side belongs to the network operator and is carried out by their approved contractor.
If we find the problem is on their side, we will tell you — you should not be paying to fix the council's pipe. Likewise, a new connection to the street main is something the council arranges rather than us.
Before you replace it
Low pressure is not always the main, and replacing one that was fine is an expensive way to find that out. It is worth ruling out the simple causes first: a partly closed toby or isolating valve, a failing pressure-limiting valve, a blocked aerator or two, or a low pressure hot water cylinder that was never going to deliver mains pressure to the shower.
We check what you have actually got at the toby and at the fixtures before recommending a new main. Sometimes the answer is a $40 part, and we would rather tell you that. If it is the hot side that is weak rather than both, the main is not your problem at all — see water and shower pressure.
What it involves
A replacement main is usually run along a new line rather than through the old trench, which keeps the existing supply live while the work is done and means the changeover is short. Where it has to cross a driveway or established planting we will talk through the route before anything is opened up.
Most domestic mains are a one-day job. We will give you a quote up front rather than running it on the clock, and the rate card is on the site if the work turns out to be charged hourly.
Get a free quote for this job
Tell us what needs doing and we'll come back to you quickly with a price. No obligation, and no charge for the quote.
If you smell gas, or have a burst pipe actively flooding your property, don't wait on a form — call 027 811 5916 now.
Common questions
How do I know if my water main needs replacing?
The usual signs are pressure that has dropped off over years, discoloured water after the supply has been off, a wet patch or soft ground between the toby and the house, or a water bill that has climbed without any change in use. Galvanised steel and early black alkathene are the two materials most likely to be at the end of their life in Christchurch.
Is the water main my responsibility or the council's?
Generally the supply line from the toby to your building is the property owner's, and the connection to the council main, the toby itself and everything on the street side belongs to the network operator. If we find the fault is on their side we will tell you rather than charging you for it.
Will replacing the main fix my water pressure?
Often, but not always — and it is worth checking before spending the money. A partly closed toby or isolating valve, a failing pressure-limiting valve, blocked aerators or a low pressure hot water cylinder all produce similar symptoms. We check what you have at the toby and at the fixtures first, and sometimes the answer is a cheap part rather than a new main.
Do you have to dig up the whole lawn or driveway?
Usually less than people expect. A replacement main is normally run along a new line rather than through the old trench, which keeps your existing water on while the work is done. Where the route has to cross a driveway or established planting, we talk it through with you before anything is opened up.
Can you run a new main to a sleepout or unit?
Yes — and running a properly sized supply from the toby is the right way to do it. Teeing a self-contained unit off the nearest convenient pipe in the house is the most common reason a retro-fitted sleepout and the main house end up competing for pressure. See our new build and sleepout page for the rest of that work.
How long does it take and what does it cost?
Most domestic mains are a one-day job. We quote this work up front rather than running it on the clock, so you know the price before we start. Where anything is charged hourly, our standard rates apply — $135 + GST for the first hour including travel, then $95 + GST an hour.
Where we work
We're a family owned business based on Wilsons Road South in St Martins, and we work right across greater Christchurch — including these suburbs and more.