In Cornwall, South West Water owns the communication pipe and the meter up to the boundary stop valve. Everything after that point, the supply pipe running to your house and all the pipework inside, belongs to you. A leak on the water company’s side is theirs to fix. A leak on your side is yours, though your buildings insurance may help with tracing it.
Someone from the water company has been out, looked at the meter, and told you the leak is “on your side”. Or a plumber has shrugged and said it is probably the company’s pipe. Either way you are stuck holding a bill that keeps climbing and no clear idea who is supposed to sort it. The rule that decides it is simpler than people make it sound, but Cornwall’s older houses, terraces and farm supplies throw up plenty of exceptions. This guide walks the pipe from the main in the road to your kitchen tap and explains who is responsible for each length. If the leak turns out to be on your section and it is buried, our underground water leak detection pinpoints it so the dig is one small hole rather than a trench across the garden.
The three pipes between the road and your tap
It helps to picture the water’s journey as three separate sections, because the ownership changes at each one.
- The water main. The large pipe under the road or lane. Owned and maintained by South West Water. If it bursts you will usually see water in the road and it is entirely their problem.
- The communication pipe. The branch that runs from the main to the boundary of your property, ending at the outside stop valve, which in most Cornish homes sits inside the meter box under a small plastic lid near the pavement or lane. South West Water is responsible for this pipe and for the meter itself.
- The supply pipe. The pipe that leaves the boundary stop valve and runs under your front garden, drive or yard to the internal stop tap. From here on the pipe is yours. So is every pipe inside the house.
The boundary is normally the edge of the highway, which is why the meter box is usually at the gate or in the pavement rather than by the front door. If your meter is inside the house (common in older properties and flats), the responsibility split is still at the property boundary, not at the meter. In that case the pipe under your garden is still yours even though the meter is indoors.
Working out which side the leak is on
You do not need to dig anything up to find out which side of the boundary the water is escaping. The meter and the two stop valves tell you.
- Turn off every tap and appliance in the house. Wait half an hour for cisterns and any tank to refill.
- Look at the meter. If the small flow indicator (a star, triangle or droplet) is moving, water is passing through it with nothing in use. That means a leak somewhere after the meter, on your side.
- Now close the internal stop tap, usually under the kitchen sink. Check the meter again. If it has stopped, the leak is inside the house. If it is still moving, the leak is on the supply pipe between the boundary and the house.
- If the meter shows nothing moving at all, yet water is pooling in the meter box or bubbling up near the boundary, the leak may be on the communication pipe before the meter. That is South West Water’s to investigate.
For a longer and more reliable version of step two, the overnight meter test gives you a litres-per-hour figure you can quote when you ring anyone. And if the box itself is full of water, water in the meter box is not always a leak on your pipe, so read that first before assuming the worst.
What South West Water will and will not do
Their side of the boundary they repair at their own cost, and they are usually quick about a communication pipe leak because it is their water being lost. On your side, the picture is different and worth understanding before you phone.
- They will not repair your supply pipe as a matter of course. It is private pipework, the same as your roof or your drains. Some water companies offer a discretionary contribution or a one-off repair on a first leak, subject to conditions. Ask South West Water what their current supply pipe policy is rather than relying on what a neighbour was offered years ago.
- They may grant a leak allowance. If a supply pipe leak has pushed your metered bill up, South West Water offers an allowance on a first supply pipe leak, provided you repair it promptly and meet their conditions. The existing guide to the South West Water leak allowance covers how to apply.
- They may write to you first. Meter readers spot continuous flow, and a letter saying “we think you have a leak” is often the first anyone knows about it. Do not ignore it. The clock on the allowance usually starts from when you were notified.
Shared supplies: terraces, converted farms and lanes with one pipe
This is where Cornwall gets complicated. A Victorian terrace in Camborne or Redruth, a row of cottages in a fishing village, or a farmhouse with two converted barns will often share a single supply pipe from one boundary stop valve. The pipe runs along the back of the row, or up a lane, feeding each property in turn.
The legal position is that a shared supply pipe is jointly owned by the properties it serves. A leak on it is a joint responsibility, even if the wet patch happens to be in one person’s garden. In practice this means three things.
- Talk to the neighbours early. Everyone on the pipe has an interest in the repair and, if there is one meter serving the row, everyone is paying for the lost water.
- Find the leak before anyone argues about money. A shared pipe can be a hundred metres long. Locating the leak to within a metre changes the conversation from “whose problem is this” to “it is a two-hour repair by the third gate”.
- Consider your own connection. Where a shared pipe keeps failing, South West Water can usually quote to give each property its own connection and meter at the boundary. It costs, but it ends the shared liability for good.
Farms and rural properties around Bodmin, Launceston and Liskeard have their own version of the problem: a supply pipe that leaves the boundary at the road and runs half a mile across fields to the house. Every metre of it is yours. Old alkathene and galvanised iron pipe on these runs fail at joints and where cattle have compacted the ground, and the leak can be a long way from where the water shows.
Who pays if it is on your side
The repair of a private supply pipe is the owner’s cost. That is the blunt answer, but there are two places the money can come from besides your own pocket.
Buildings insurance and trace and access
Most UK buildings policies include trace and access cover. It pays for finding the leak and for the making good afterwards (the digging, the floor, the plaster), typically up to a limit in the £5,000 to £10,000 range. It does not pay to repair the failed pipe itself. So the survey, the excavation and the reinstatement are often claimable while the new length of pipe and the plumber’s time to fit it are not. Our guide to what trace and access insurance covers goes through the wording to look for.
Landlords and holiday lets
If the property is rented out, section 11 of the Landlord and Tenant Act 1985 puts the installations for the supply of water in repair on the landlord, so a supply pipe leak is the landlord’s to fix, not the tenant’s. Holiday let owners in places like Padstow, St Ives and Looe have a further problem: nobody is there to notice a leak between changeovers, and a supply pipe can run for weeks before the bill lands. A leak allowance claim still needs the repair done promptly once you know.
The order to do things in
| Step | Why it matters | Who does it |
|---|---|---|
| Meter test with the internal stop tap open, then closed | Tells you inside, supply pipe, or before the meter | You |
| Report a leak before the meter to South West Water | Their pipe, their repair, no cost to you | You, by phone |
| Check your buildings policy for trace and access | Decides whether the survey and dig are claimable | You |
| Locate the leak on the supply pipe | Turns a trench into a single hole and gives you a report for the claim | Leak detection specialist |
| Repair and keep the invoice | Needed for the leak allowance application | Plumber or groundworker |
| Apply for the leak allowance with before and after readings | Recovers some of the lost water charges | You |
Cornwall’s soft water is kind to pipes in one way, because it does not scale them up, but it is slightly acidic and old copper and iron supply pipes can pit and pinhole. A supply pipe that fails once at forty years old will often fail again nearby, and a leak report that notes the pipe’s condition helps you decide whether to repair or replace the run. We provide leak detection across Cornwall, from the Tamar to Land’s End, and a supply pipe from the lane to a farmhouse outside Lostwithiel is a very ordinary day’s work.
Frequently asked questions
Is the water meter itself my responsibility?
No. The meter belongs to South West Water and so does the pipe feeding it from the main. If the meter is damaged, frozen or leaking at its own fittings, report it to them. Your responsibility starts at the outlet side of the boundary stop valve, where the supply pipe heads towards your house.
My meter is inside the house. Where does my responsibility start?
Still at the property boundary, not at the meter. The pipe under your garden is yours even though the water is not measured until it reaches the kitchen. This surprises a lot of owners of older Cornish cottages where the meter was fitted indoors because there was no room at the lane.
The leak is on a pipe shared with my neighbours. Who pays?
A shared supply pipe is jointly owned by the properties it serves, so the repair is a shared cost, whichever garden the water surfaces in. Locating the leak precisely first keeps the job small and makes splitting the bill far easier. South West Water can quote for separate connections if the pipe keeps failing.
Will South West Water fix a leak on my supply pipe?
Not as a matter of course, because it is private pipework. Some water companies offer a contribution or a one-off repair on a first leak with conditions attached. Ask South West Water directly what applies to your property rather than assuming, and ask about the leak allowance at the same time.
Can I claim the cost of finding the leak on my insurance?
Often, yes. Most buildings policies include trace and access, which covers locating the leak and reinstating what had to be disturbed, up to a limit. The repair of the pipe itself is usually excluded. Check your own wording and keep the survey report, photos and invoices together.
Not sure whose pipe it is?
We locate the leak on your supply pipe to within a metre, so the repair is one small hole and the argument about responsibility is over before it starts. Every survey comes with a report your insurer will accept for a trace and access claim.
