There are two reports, and they are not the same thing
Almost everyone searching for this has one of two situations, and the consequences are opposite.
| What you have | What reporting it does |
|---|
| Water surfacing in a road, pavement, verge or public space | Puts the job in Thames Water's repair queue. Costs you nothing, commits you to nothing. |
| Water on your side of the boundary stop valve | Starts the clock. Thames Water's position is that once a leak at your property is confirmed, you must arrange repair within four weeks. |
The first is a civic act. The second is an obligation, and it is worth being certain of the facts before you take it on.
What counts as worth reporting to them
Report water in a public place with no ordinary explanation:
- Water running along a kerb or gutter in dry weather, with no rain for a day or more.
- A wet patch on a pavement or road that never dries out, or that darkens the tarmac in a fixed shape.
- Water bubbling up through paving, a crack, or around a utility cover.
- A stop tap or hydrant cover in the footpath with water standing in the chamber, or hissing when you lift the lid.
- A sunken or spongy patch of road or footway — a long-running main leak washes the ground out before it breaks the surface.
- Clear water still running into a gully or a basement lightwell long after rain has stopped.
Thames Water say over 95% of leaks are never seen by customers, because most are small, deep and underground. The ones that do reach the surface are exactly the category they ask the public to report.
What is yours, where reporting will not help
These are all leaks. None of them is a Thames Water repair:
- A dripping tap, a running overflow, or a toilet trickling into the pan.
- Water through a ceiling from a bathroom, a radiator or the flat above.
- A wet patch in your own garden, driveway or front path.
- Anything past your internal stop tap.
- A leak on a supply pipe that only serves your property — even where it runs under a neighbour's land or under the public footpath.
Reporting these does not get them fixed. It gets them logged against your address. If you rent, none of it is yours to fix either: Thames Water's position is that the landlord is responsible, so the report to make is a written one to the landlord or agent, with a copy kept.
Where the boundary sits, in one paragraph
Thames Water own the water main and the communication pipe running from it to the outside stop valve at your boundary. From that valve into the house, the supply pipe is yours. The valve itself is their apparatus, and so is the meter — and their code of practice states plainly that the position of the meter does not determine pipe ownership or responsibility. That matters in London, where the meter is routinely in the footpath outside a terrace, or in a communal chamber for a whole row. Neither position moves the line. The full version — shared supplies, pipes crossing other land, who pays — is on our page on who is responsible for a leak outside the house.
Work out which side yours is on first
The meter test
Thames Water publish this and it takes half an hour. Turn off the internal stop valve, usually under the kitchen sink. Check no cistern is filling and every tap is off. Read the meter, leave the valve shut half an hour, read it again. The two readings should match. If the number has gone up, water is being lost between the meter and your closed internal valve — that is your supply pipe, outside the house. If it has not moved but the bill is still high, the loss is inside, past that valve. The dials and the common misreadings are in how to read your water meter to find a leak.
The signs they list
Thames Water name four: reduced flow or pressure at the cold kitchen tap, waterlogged or damp ground in the garden even in dry weather, noisy pipes, and an unusually high metered bill. Any of those alongside a meter that creeps with everything off points at your supply pipe, not theirs.
If you have no meter
You cannot run the test, and an unmetered bill does not move with usage either. It comes down to the physical evidence: where the wet ground sits relative to the boundary, and whether it ever dries. Inside your boundary and never drying is almost always yours.
How to report it
For a leak in a road, pavement or public space, Thames Water direct you to report it online. Their leakage code of practice gives the short address thameswater.co.uk/leak, which lands on their "Report a problem" service, and their leak repair process page points the public to the same route. They also run a WhatsApp channel, available 24/7.
The form is a location form before it is anything else. Have ready:
- Where it is. Nearest address or postcode, and which side of the road. A house number opposite the wet patch beats a street name alone.
- What you can see. Running, standing, bubbling up or a sunken surface. Clear or dirty.
- How long it has been there. "Since at least Tuesday" separates a burst from a wash-off.
- Whether anything is at risk. Water crossing a carriageway, entering a property, or icing over.
For a leak you suspect is on your own supply pipe, the code of practice gives a phone route instead: call 0800 316 9800, which it describes as open 24 hours, 7 days a week. Read the next two sections before you do.
What happens after you report a public leak
Thames Water publish their process in four stages. It is worth knowing, because it explains why the hole in the road does not appear the next morning.
- Locate. Your report goes to a leakage team, alongside what their own detection work has picked up in the area.
- Investigate and prioritise. They assess the repair and its urgency. The four factors they name are the amount of water being lost, the effect on customers' water supply, complexity, and location.
- Plan the logistics. Closing a road means working with the council and the highways authority, and a leak near gas or other services means coordinating with those companies. They say they close roads at night where they can, and write to customers near the site.
- Repair and resurface. A team attends, sometimes digging to the pipe by hand where it sits among other utilities, and the road is resurfaced afterwards.
We will not put a timescale on that, because Thames Water do not publish one covering every leak and an invented number would be worth nothing to you. The criteria tell you the shape of it: a large loss affecting supply moves up, a slow weep in a quiet footpath does not.
The part people get wrong: reporting your own leak starts a clock
Thames Water's guidance on leaks at home is direct — once you discover a leak, you must arrange repair within four weeks, counted from them confirming it. Run past that and section 75 of the Water Industry Act 1991 lets them carry out the repair and charge you for it, and in an emergency they say they may turn the supply off until it is repaired.
A second detail worth knowing first: if you do not use a WaterSafe approved plumber, Thames Water say they may come out to check the work, and will carry out and charge you for extra repairs if they think they are needed.
So the order matters. Reporting a leak that turns out to be on your side does not get it fixed — it puts a deadline on you fixing it. Confirm it with the meter, find out where it actually is, then report. If a letter has already arrived, the sequence is on our page on what to do when Thames Water say you have a leak.
One good reason to report it anyway
If you are metered you are billed for every litre passing the meter, including everything the leak has wasted. The leak allowance exists to put that back, and it is tied to acting inside the four weeks and producing proof of repair. Reporting and repairing promptly is what makes the claim work; sitting on it is what kills it. The eligibility rules, the exclusions and the form are on our page on the Thames Water leak allowance.
When to call us, and when not to
Not us: water in the road or pavement — report it to Thames Water, free. A tenant with a leak — the landlord, in writing. A visible weep on an accessible joint in an open trench — any competent plumber can remake that, no detection needed. Anyone on the Priority Services Register, WaterHelp or WaterSure — ask Thames Water first, because they say they will help in those categories at their discretion.
Us: the leak is inside your boundary, nobody can say where on the run it is, and there is a solid floor, a resin drive, a tiled path or a bay window over the top of it. We trace with acoustic equipment, thermal imaging and tracer gas on a drained line, repair the pipe, and our own handymen and builders put back what was opened. Mains and supply pipe repair is £150 per hour, agreed before we attend, with no call-out fee — and if we do not find the leak, you do not pay for the time we spent looking.
