Grange PlumbingThe short answer
In England and Wales, the underground pipe that runs from the water main in the street to the inside of your home is split into two parts. The water company looks after the section in the public highway (the communication pipe). You, the homeowner, are responsible for the section that runs from your boundary into the property — this is the supply pipe. If the supply pipe leaks, bursts, or needs replacing, the cost is yours.
Where exactly is the boundary?
The legal boundary is usually the edge of your property — typically the front wall, fence or pavement edge. The external stopcock (often a small metal cover marked 'W' on the pavement or just inside your boundary) marks the handover point. Everything from there into the house — usually buried 750mm under your front garden, drive or path — is the supply pipe and is your responsibility.
What does the water company cover?
Your water supplier (in our area that's typically SES Water, Southern Water or Thames Water depending on postcode) is responsible for the main in the road and the communication pipe up to the boundary. If a leak is on their side, they'll repair it free of charge. They will also normally come out and check whether the leak is theirs or yours before you commit to any work — always worth requesting first.
What if the supply pipe is shared?
Older properties — especially Victorian terraces — often share a single supply pipe between two or more houses. Responsibility is split between the homeowners. Shared supply pipes are a common cause of disputes, and most water companies now offer free or subsidised separation schemes to convert them into individual supplies. It's worth asking your supplier whether you qualify before paying for a replacement yourself.
Is supply pipe replacement covered by insurance?
Standard buildings insurance usually does NOT cover replacing the supply pipe itself — only the resulting damage from a burst. Most water companies offer optional 'supply pipe insurance' for around £2–£5 per month, which covers repair or replacement up to a set limit. If you've lived in the property for a while, check your renewal documents — many people pay for this without realising. There's also HomeServe and similar standalone policies.
Signs your supply pipe is failing
Common warning signs include: an unexplained jump in your water bill, a constantly running water meter when no taps are on, damp patches in the front garden or driveway, low water pressure throughout the house, or visibly green/lush patches of lawn over the pipe route in dry weather. Old lead and galvanised steel supply pipes (anything pre-1970s) are the usual culprits — and lead pipes are also a health concern worth replacing regardless.
What to do if you suspect a leak
First, turn off your internal stopcock and check whether the meter is still ticking — if it is, the leak is on your supply pipe. Then call your water company and ask them to confirm whether the leak is on their side or yours. If it's yours, get a fixed quote for moling (trenchless replacement) rather than a traditional dug trench — it's almost always faster, less destructive and cheaper once reinstatement is included.
How we can help
We replace supply pipes across Sussex and Surrey using moling — the new MDPE pipe is installed underground in a single day with no trench across the garden or drive. We offer free site visits and fixed written quotes, and we'll happily liaise with your water company on the boundary side.
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