A practical UK household guide
Emergency water supplies at home
How much drinking water is useful to keep, where should the bottles go, and what should you do if the tap stops working? Here is a clear plan you can put together gradually, with a calculator based on current UK guidance.
The UK government's Be Ready advice recommends three days of drinking water. Seven and fourteen day reserves are optional household choices, not government requirements.
Begin with three days, then decide what fits your home
The government's Be Ready checklist recommends bottled water for three days at 3 litres per person per day for drinking. That is 9 litres for one person, 18 litres for two and 36 litres for four. It is a starting point for drinking water, not a promise that it covers cooking, cleaning or every household need.
If you have the space and want a longer reserve, seven days means 21 litres of drinking water per person and fourteen days means 42 litres. You do not need to buy it all at once. Check what is already sealed and in date, then add a bottle or two during ordinary shops. If space or cost is tight, start with what you can safely keep.
The amount of water is only part of the plan. Know which company supplies your home, how you would hear about an outage, and whether somebody in your household might need help collecting an alternative supply.
Household water calculator
Work out your drinking water reserve
The starting point is 3 litres per person per day for drinking. Choose three, seven or fourteen days, then enter any extra amount you want to plan for other needs. The calculator never treats that extra amount as part of the official drinking water figure.
For comparison, the official three day drinking water baseline for this household is 9 L. Bottle counts round up to whole bottles. This tool does not decide how much water you personally need for pets, formula, medical equipment, cooking or washing. Ask the relevant care team or provider about specialist needs.
Before an outage
Where and how should you store the water?
Factory sealed bottled water is the simplest choice for a household reserve. The government's water outage advice calls it the safest way to prepare. Choose bottles you can lift and handle, especially if a heavy multipack would be difficult to carry.
Cool and out of the sun
A cupboard or low shelf in a cool room is better than a sunny window, hot loft or car boot. Keep bottles away from strong smelling chemicals and anything that could damage the packaging.
Sealed and easy to reach
Keep the caps and seals intact. Put the bottles somewhere people can find them without electric lighting, but not where they could fall or block an exit.
Checked and rotated
Follow the best before date and storage instructions on your particular bottle. Put newer bottles behind older ones and review the reserve every six months.
Do not assign a made up shelf life to refilled containers. If you are considering storing tap water yourself, use containers intended for drinking water and seek your water supplier's advice on cleaning and replacement. For a simple long term reserve, sealed commercial bottles avoid uncertainty about how a reused container was cleaned.
Once a bottle is opened, follow its label for storage and use. Smaller bottles can be easier to finish when there is no working fridge. Check a bottle again before drinking if its seal is broken, the packaging is damaged or the water looks or smells unusual. If you have a question about your tap water, GOV.UK advises contacting your water company.
When the taps stop
The first things to do during a water outage
- Check the provider's update. Your water company is the best source for the affected area, estimated repair time and collection points. Keep its website or phone number with your household contacts. For England and Wales, Ofwat lists water companies. You can also check Scottish Water updates or NI Water updates.
- Read the actual notice. No water, a boil water notice and a do not drink or do not use notice need different responses. Follow your provider's instructions rather than a general article or a social media post.
- Keep safe water for essential uses. Drinking, preparing food and handwashing come first. Check separately for babies, pets and any medical equipment that uses water.
- Ask for help if it is hard to collect water. The provider may offer alternative supplies. If you are eligible for its Priority Services Register, sign up before an outage or contact it during one.
The official Be Ready outage guide explains what to do before, during and after a disruption. A rain butt may help with flushing a toilet or watering plants, but its contents are not drinking water.
Different notices, different actions
What if the water is unsafe?
It is important not to treat every incident as a simple power cut. Your supplier's notice tells you what can and cannot be done with the tap water. If you have a private supply, your local authority is the first contact for advice about its safety.
Supply interruption
Water may not be reaching the taps. Check your supplier's incident page for updates and where alternative drinking water is being provided.
Boil water notice
Follow the exact notice. The Drinking Water Inspectorate says water covered by such a notice must be brought to a boil for drinking, brushing teeth and preparing food. Cool it safely and keep it in a clean container as instructed.
Do not drink or do not use
These are not boil water notices. Do not assume that boiling makes the water safe. Use the alternative supply and follow the specific restrictions from your water company or local authority.
If a flood has affected your home or supply: do not guess from the appearance of the water. Follow your water company or local authority's advice. The UK Health Security Agency's flood guidance explains why different water safety notices are used.
A plan that fits your household
Babies, pets and medical needs
Some households need more than a simple litre figure. For a baby who uses formula, the government's water outage advice says ready to feed formula is the safest option if you cannot boil water or sterilise equipment. Bottled water is not normally recommended for making powdered formula because it is not sterile and may contain too much sodium or sulphate. If it is the only option during an emergency, follow the detailed Be Ready guidance and the NHS formula instructions, not a general calculator.
If medical equipment needs water, ask the care team how to prepare for a supply interruption and what water is suitable for that equipment. For pets, note their usual drinking needs separately. The calculator above leaves an optional extra field for needs you have worked out yourself; it does not prescribe these amounts.
If someone may need help receiving or collecting replacement water, ask the provider about its Priority Services Register. Make that enquiry before an outage if possible.
Keep this information with your plan
Write down your water provider's name, incident phone number, any household needs that change the water plan, and where you keep the bottles. The full ChatFriends emergency plan has space for household contacts and essential details.
Sources and review
Checked against current UK guidance
Written by ChatFriends and checked on . During an actual incident, follow your own provider's latest notice. It takes priority over this general guide.
Put water into the wider household plan
Water is one part of being ready. The main guide covers food, power, useful supplies and a printable checklist.