How to Report a Water Leak in Chelsea

Updated July 2026 · Emergency Plumber Chelsea

Start with one question: where is the water actually coming from? If it is bubbling up through the road, the pavement or a grass verge, it is on the public network and belongs to Thames Water. If it is inside your home, your garden, or anywhere past your boundary, it is your private supply and you deal with it yourself, usually by calling a plumber. If it is in a communal riser, a shared cold water tank or a pipe that serves more than one flat, it belongs to the building, so you tell the managing agent or freeholder. Getting this right first saves you chasing the wrong people while water keeps running.

For a leak in the street or on the public main, report it to Thames Water on 0800 714 614 or through the leak reporting form on their website. Thames Water owns the water main and the communication pipe that runs from the main up to your property boundary, so anything leaking on that side is theirs to fix at no cost to you. Typical signs of a public leak in Chelsea include water welling up through the tarmac or paving, a patch of highway or footway that stays wet in dry weather, water running along a gutter from no obvious source, or damp and movement around a stopcock cover set into the pavement. You do not need to be certain it is theirs. Report what you can see and Thames Water will investigate and trace it.

The Royal Borough of Kensington and Chelsea also has a report-it page for water leaks, drainage and flooding on public land. Use the RBKC route when the problem is on a road, pavement or council-owned land, when a blocked or surcharging highway drain is flooding, or when you are not sure whether the leak sits with the water company or the council. In practice the council and Thames Water coordinate on highway leaks, so reporting to either gets the ball rolling. If water is flooding the public highway and posing a danger, treat it as urgent and phone Thames Water directly rather than only filling in a form.

For a leak inside your boundary or on your own pipes, it is a private matter and you call a plumber, not the water company. You own the supply pipe from the outside stop valve at your boundary all the way into your home and up to the inside stopcock, along with every pipe, tap, valve, cylinder and appliance beyond it. Thames Water will not repair any of that. This covers the vast majority of the leaks people find at home: a dripping joint under the sink, a weeping radiator valve, a leak under the floor, a burst inside a wall, or a wet patch in the garden over a buried private supply pipe. If it is on your side of the boundary, book a plumber to trace and repair it.

To confirm a leak is on your private supply, use your water meter and stopcock. Turn off every tap and water-using appliance, then find your water meter and note the reading, or watch the small flow indicator dial. If it keeps moving with everything off, water is escaping somewhere on your side. You can narrow it down further by turning off your inside stopcock: if the meter stops, the leak is inside the property or on internal pipework; if it keeps running with the stopcock closed, the leak is on the underground supply pipe between the boundary and the house. Either way the repair is yours to arrange.

In a mansion block or shared building, report a leak on communal pipework to the managing agent or freeholder rather than trying to fix it yourself. Shared risers, communal cold water storage tanks, pipes in service voids and anything that feeds more than one flat are the building's responsibility, and only the agent or freeholder can authorise work on them or shut off a shared riser. If your building has a concierge or porter, tell them first so they can isolate the affected riser and warn the flats below. Keep the agent's out-of-hours number to hand, because a communal leak at night still needs someone with authority to act.

If the water is coming through your ceiling from the flat above, that is a common Chelsea situation and it has its own order of steps. Protect your own property first, then contact the neighbour and the managing agent, because you generally cannot access or isolate someone else's supply without their consent. A plumber can help you make safe on your side and identify where the water is tracking from, but the repair itself sits with whoever owns the failing pipe upstairs. Our guide to a ceiling leak from the flat above walks through this in detail.

Whoever you report to, give them the same clear information: the exact location, what you can see, how long it has been happening, and whether it is getting worse. For a street leak, note the nearest house number, junction or landmark and whether the water is clean or dirty. For a private leak, note which room or which stretch of garden, whether it is a steady drip or a fast flow, and whether it is near electrics. Photos and a short video help both a plumber and the water company understand the scale before anyone attends. If you have already isolated the water at the stopcock, say so, because that changes how urgent the response needs to be. Keep a note of the reference number you are given so you can chase progress, and check back if a reported street leak is still running a few days later, as some take more than one visit to trace underground.

Some situations override the decision path and need a different first call. If you smell gas or suspect a gas leak at any point, leave the property and call the National Gas Emergency Service on 0800 111 999 before anyone else. If a private leak is actively flooding your home, turn off the main stopcock and open a cold tap to drain the pressure before you start phoning around, then get an emergency plumber out. A contained drip can wait for a booked visit; water running into electrics, through a ceiling, or across a floor cannot, and out-of-hours attendance exists for exactly that.

Chelsea's housing makes a few of these calls more likely than average. Period terraces and mansion flats in SW3 and SW10 often still have older lead or galvanised supply pipes that fail at joints, basement conversions add pumped drainage that can leak below ground, and stacked flats mean one leak quickly becomes several people's problem. Knowing in advance where your stopcock is, who your managing agent is, and that Thames Water handles the street side takes the panic out of the moment you find water where it should not be. For a leak on your own side of the boundary anywhere in SW3, SW10 or nearby, call Emergency Plumber Chelsea on 020 3002 6667 and we will trace it, make safe and quote before major work.

Quick tips

• Decide first: street or public main is Thames Water (0800 714 614); inside your boundary is a plumber; shared pipes are the managing agent or freeholder.
• Use the meter test to prove a private leak: with all water off, a moving meter means water is escaping on your side.
• Report a public leak with the nearest house number, junction or landmark, plus whether the water is clean or dirty.
• In a mansion block, tell the concierge or managing agent so they can isolate the shared riser and warn the flats below.
• If you smell gas, leave and call National Gas Emergency on 0800 111 999 before making any other call.

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