Turning Off Gas, Electricity and Water Before a Flood

If flood water is about to enter your home, the advice from councils and fire and rescue services across the UK is the same: turn off the gas, electricity and water at the mains, but only if it is safe to do so¹. Doing it before the water arrives is what prevents the worst outcomes, an electrical supply meeting flood water, a gas leak in a flooded building, or contaminated water backing up through the pipes.

The catch is that most people have never located their stopcock or fuse box switch, and a flood is the wrong moment to start looking. Learn where each shut-off is now, while the house is dry and the lights are on, and note it in your household flood plan. The steps below take you through what to do when a warning comes, what to do if water is already inside, and how to bring the supplies back safely afterwards.

When to turn the supplies off, and when to leave them alone

The trigger is not the weather warning itself but the water. Council and fire service guidance is consistent that you turn off gas, electricity and water supplies when flood water is about to enter your home, and only if it is safe to do so¹. Natural Resources Wales gives the same instruction for households in Wales: during a flood, turn off gas, electricity and water⁸. If you are evacuating rather than staying, the advice is to turn off your mains water, gas and electricity before you leave, again only if it is safe³.

A flood warning is the point to get ready, not to cut the supplies while you still need them. The Northumberland flood warning level "Act" sets out the sequence: turn off gas, water and electricity, move things upstairs or to safety, and move family, pets and car to safety⁹. Natural Resources Wales puts moving family, pets and valuables to a safe place first, then turning off the supplies if it is safe, then putting flood protection in place⁸. Either order works, as long as the shut-offs happen before the water is at the door.

Flash flooding is the case that catches people out, because it can arrive with very little notice¹⁰. That is the strongest argument for learning the shut-offs in advance rather than reading about them during the event. The same applies to severe weather more broadly: Met Office advice for heavy rain includes turning off gas, water and electricity supplies¹¹, and its thunderstorm advice says the same¹².

Where to find the gas valve, the electricity mains and the water stopcock

Every property is laid out differently, but the usual locations are well established. The water stop tap is usually inside your home where the supply comes in, or outside near your property boundary under a cover. The gas shut-off valve is usually next to your gas meter. The mains electricity cut-off is on your fuse board, as a large on and off switch¹³. Natural Resources Wales describes the same three: the gas valve next to the gas meter, the electricity main usually a red switch on the fuse box, and the water stopcock usually under a kitchen sink or where the pipe enters the home⁸.

Go and find all three this week, in daylight, and photograph them on your phone. If you live in rented accommodation and cannot find them, ask your landlord or letting agent. The Dover District Council guidance is blunt about the priority: find out now if you do not know where they are¹⁴.

• Water: stop tap where the supply enters, often under the kitchen sink, or outside at the boundary under a cover¹³
• Gas: shut-off valve next to the gas meter¹³
• Electricity: the main switch on the fuse board, often red⁸

What to do when a warning comes: a step-by-step

When a flood warning is issued for your area, work through the following in order. It follows the official "Act" sequence and the personal flood plan checklist⁹.

1. Get your flood kit and put your flood plan into action⁸.
2. Move important items to safety. Take valuables, documents and electrical items upstairs or well above expected water level⁸.
3. Lift what you can. Lift rugs and smaller furniture onto tables or worktops, and lift curtains over their rails above flood water level¹⁵.
4. Deal with the outside. Move or weigh down large or loose items, and move your car to higher ground⁸.
5. Put flood protection in place if you have it, such as door guards or air brick covers⁸.
6. Turn off gas, electricity and water at the mains, if it is safe to do so¹.
7. Charge phones and devices before the power goes off¹⁵.
8. Move family and pets to a safe place, upstairs or to higher ground⁹.

Before you switch off the electricity, it helps to unplug appliances and switch them off at the socket. Lancaster City Council's guidance is to switch off all electrical appliances, remove plugs from sockets and turn off the main electricity switch, and it notes that freezers and fridges will become ineffective once the power is off¹⁶. Plan for the food in them accordingly; our guide to emergency food covers what keeps and for how long.

If you are in a flat or a building with shared supplies, the same principles apply but the shut-offs may be in a communal area. Ask your building manager or neighbours now, not during the flood.

If water is already inside the house

Once flood water has entered, the priority changes from protecting property to protecting people. Fire and rescue services are clear: get family and pets upstairs or to higher ground, and do not attempt to turn off the electricity while standing in water⁵. If you can reach the fuse board safely, without wading, turn off the electricity at the mains; if you cannot, leave it⁵.

Cumberland Council's guidance for a flooded home or business is to switch off the electricity at the fuse box and turn off the water and gas at the mains, if it is safe to do so¹⁷. The words "if it is safe" carry the whole weight here. A gas valve next to a meter in a flooded cellar is not safe to reach. A stopcock under a sink surrounded by standing water is not safe to reach.

If you have to leave, do so, and do not walk or drive through flood water on the way. Our page on what to do during a flood at home sets out the wider sequence, and walking or driving through water explains why moving water is so dangerous.

Learning the shut-offs now, and writing them into your plan

The single most useful thing you can do this month is learn how to turn off your gas, electricity and water safely, and write down where each one is⁶. The Scottish Environment Protection Agency's flooding guide for older communities puts it plainly: learn how to shut off gas, electricity and water supplies and make a note of this in your flood plan⁶. The government's Be Ready campaign makes the same point, adding that you will need to turn these off if you have to leave your home because of flooding or a leak¹⁸.

The government's personal flood plan template asks you to check you know how to turn off your electricity and water¹⁹, and the fuller version includes turning off electricity, water and gas supplies among the things to do immediately before a flood, alongside lifting curtains, using door guards and moving important items to safety¹⁵. Cheshire Fire and Rescue Service folds it into the wider household emergency plan: learn how to turn off your gas, electricity and water safely, check your home insurance cover and sign up for flood and weather alerts²⁰.

• Write it down: where each shut-off is, and what it looks like⁶
• Photograph it: a picture of each valve and switch on your phone¹³
• Tell the household: everyone old enough should know, not just one person²⁰
• Check it works: turn the water stop tap gently and back, so you know it is not seized¹³
• Add it to your plan: note it in your household flood plan⁶

If you have not yet signed up for warnings, our guide to signing up for free flood warnings explains how, and flood alerts, warnings and severe flood warnings explains what each level means. For Wales specifically, see Natural Resources Wales warnings and risk maps.

Bringing the supplies back on after a flood

Do not rush this. The electricity is the one to treat with most caution: have all electrical circuits fully dried out and checked by an electrical engineer before switching back on⁵. That is not a step to skip because the lights seem to work. Our page on whether it is safe to turn the electricity back on goes through it in detail, and using electrical appliances after water damage covers what to do with individual items.

For gas and water, if you are in any doubt, contact your supplier or a qualified engineer rather than testing the supply yourself. The general principle from the official guidance is that the utilities go off before the water arrives and come back on only once the property is dry and checked⁵. Returning home after a flood is a staged process; our guide to returning home safely after a flood sets out the order, and cleaning up safely after floodwater covers the health precautions once you are back inside.

Where to get help

If you need assistance turning off supplies, or you are older, disabled or medically dependent, ask now rather than during a flood. Your water company's Priority Services Register can help during supply interruptions, and our guide to extra help in an emergency explains who qualifies and how to sign up. For warnings and practical help during a flood, the government's help during a flood page is the starting point²¹, and our page on who to report flooding to covers the councils and agencies to contact.

In an emergency where life is at risk, call 999. For flood warnings in England and Wales, sign up in advance; for Scotland, see the SEPA guidance⁶. Wherever you are, the principle is the same: know your three shut-offs, act before the water arrives, and never take a risk with electricity and water together.