What should I do if a water main bursts in my street?

A burst main releases a very large volume of water at pressure, and most of the damage is not from the water reaching a house but from what it does to the ground. It washes out the material under the road and the pavement, undermines drives and garden walls, and floods cellars and underfloor voids from below rather than through the door. It also usually means the supply will be off for a while afterwards, and that the water will run discoloured when it comes back.

Safety

What you'll need

• Your water company's 24-hour emergency number
• Knowledge of where your internal stopcock is
• A phone with a camera
• Flood boards or airbrick covers, if you have them (optional)
• Bottled water for the interruption

Step by step

1. Ring the water company's emergency line and report it.Give the road, the nearest house number, how much water and where it is going. They are the only people with the equipment and the legal right to shut a main down.
2. Keep everyone away from the water and the road.Moving water hides the hole it has made. Children, dogs and anyone trying to photograph it from close up are the risk here. Do not stand on a manhole cover in flowing water.
3. Shut your own internal stopcock if water is reaching the property.It stops your own plumbing drawing dirty water in and stops any back-siphonage. It is normally under the kitchen sink; the external stop tap in the pavement is the water company's and needs their key.
4. Protect the low openings if you have anything to hand.Door barriers, airbrick covers, and sealing round service ducts through the wall. A single unprotected opening undoes the rest, so get to all of them or none.
5. Move what matters upstairs or off the floor.Documents, electronics, photographs, anything irreplaceable. Ten minutes of lifting is worth more than any amount of mopping later.
6. Ring 105 if it is anywhere near electrical infrastructure.A flooded substation, meter box, cable pit or street cabinet is a serious hazard and the distribution network needs to know. 105 is free from any phone.
7. Do not drive through it, and warn others who are about to.The road surface may be undermined. Water deep enough to reach the sills will also flood the engine and the electrics of most cars, and moving water can shift a vehicle.
8. Photograph and video everything.The water, the depth, the time, the damage to the drive, wall, garden and inside the house. Water companies pay compensation for damage caused by a burst main, and the evidence is what settles it quickly.
9. Expect the supply to be off, and then discoloured.Fill containers before it goes off if you can. When it comes back it will very likely run brown or milky — run the kitchen cold tap gently until it clears, and do not put a wash on until it does.
10. Claim, from both the water company and your insurer.Tell your buildings insurer straight away, and put a claim to the water company as well. Water companies also pay fixed amounts under their guaranteed standards scheme for prolonged supply interruptions.

Tips

• Know where your internal stopcock is and check it turns, twice a year. A stopcock seized open is useless in exactly this situation, and freeing it is a five-minute job on a normal day.
• Water companies must provide alternative water — usually bottled or a bowser — where a supply interruption lasts beyond a set time. Ask; it is not always offered.
• If the burst has undermined your drive, wall or garden, that is damage caused by the burst and is claimable. Photograph it before anyone starts backfilling.
• A burst on your own supply pipe, between the boundary stop tap and the house, is normally your responsibility rather than the water company's — many companies run a free or subsidised repair scheme for it, so ask.
• Sign up to the water company's Priority Services Register if anyone in the house is vulnerable or depends on water for medical equipment. It gets you bottled water delivered rather than collected.

Common mistakes

• Trying to turn off the external stop tap in the pavement — It is the water company's asset, needs a long key, and operating it wrongly can damage the main or interrupt neighbours. Ring them; that is what the emergency line is for.
• Driving through to get to work — The road surface may be undermined and the depth is unreadable in moving water. Cars are written off in surprisingly shallow water and people drown in surprisingly little.
• Clearing up before photographing — The claim, against the water company and the insurer, is only as good as the evidence. Ten photographs before the mop comes out is the difference.
• Using the water as soon as it comes back on — It will be carrying sediment lifted from the main. Run the kitchen cold tap gently until clear before drinking, bathing or washing clothes.

If it doesn't work

Questions people ask