How Much Emergency Water Should You Store? UK Guide

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How much emergency water should you store?

The short answer: keep at least three days’ supply of bottled drinking water for everyone in your home. Allow around 3 litres per person per day for drinking and basic cooking, and more – up to about 10 litres per person per day – if you want enough for washing and hygiene too. Don’t forget pets.

Quick guide: how much to store for three days

1 person: 9 litres minimum (up to 30 litres including washing)
2 people: 18 litres minimum (up to 60 litres)
4 people: 36 litres minimum (up to 120 litres)
A medium-sized dog: add about 1–2 litres a day

You’ll need more in hot weather, if anyone is unwell, pregnant or breastfeeding, or if you have a baby who needs formula made up.

Why three days?

Most water supply interruptions in the UK are fixed within hours, and water companies usually set up bottled water stations for longer outages. Three days gives you a comfortable buffer while help is organised. If you or someone you live with is vulnerable, sign up to your water company’s Priority Services Register – they can prioritise bottled water deliveries during an outage.

The easiest ways to store water

Shop-bought bottled water is the simplest option – it’s sealed and has a long best-before date. Rotate it into everyday use before it expires and replace it.
Large water containers filled from the tap are cheaper for bigger quantities. Use food-grade containers designed for drinking water, clean them before filling, and refill them regularly.
Fill the bath and pans if you get warning of a supply problem – useful for flushing toilets and washing, but not for drinking.

Store water somewhere cool and dark, out of direct sunlight and away from fuel, paint and cleaning products. Never reuse containers that have held chemicals.

Our recommended water storage products

Reliance Aqua-Tainer 26 litre water container

Best for: storing larger amounts at home

A tough, food-grade, stackable container with a built-in tap. Two of these hold enough drinking water for a family of four for over four days.

Check the latest price on Amazon

20 litre collapsible water carrier

Best for: flats and small spaces

Folds flat when empty, so it takes up almost no room until you need it – ideal if you get warning of a supply interruption.

Check the latest price on Amazon

Stackable water storage containers

Best for: making the most of cupboard space

Smaller 10-litre containers are easier to lift and pour, and stack neatly in a cupboard or under the stairs.

Check the latest price on Amazon

Water purification tablets

Best for: a back-up if you have to use water you’re not sure about

Small, light and long-lasting. Keep a pack in your emergency kit alongside your stored water.

Check the latest price on Amazon

Sawyer Squeeze water filter

Best for: filtering water if stored supplies run out

A lightweight filter that removes bacteria and protozoa. Combine it with purification tablets or boiling to deal with viruses.

Check the latest price on Amazon

Using stored water safely

If your water company issues a “boil water” notice, bring water to a rolling boil and let it cool before drinking.
Never drink water from a dehumidifier, swimming pool, radiator or toilet cistern.
If you’re unsure about stored water, treat it with purification tablets or boil it.

Water is one part of a wider kit – see what should be in a UK household emergency kit. For hydration on the move, read our guide to hydration and kits, and for longer droughts see coping with water shortages in the UK.

Water Collection Ideas

There are many ways to collect water, depending on your location and the availability of natural resources. Some common methods include:

Rainwater harvesting: This involves collecting and storing rainwater that falls on rooftops or other surfaces. Rainwater can be collected in barrels, water butts, tanks, or cisterns and can be used for irrigation, flushing toilets, and more. Please read the latest rainwater harvesting UK laws here.

Surface water collection: This involves collecting water from rivers, streams, lakes, and other bodies of water. Surface water can be collected using buckets, containers, or pumps and can be used for irrigation and other purposes. If you need to drink it, it must be filtered and purified first (see below).

Groundwater collection: This involves collecting water from underground sources, such as aquifers. Wells are the most common method of groundwater collection and can be dug by hand or by machine. Do note that you cannot simply dig anywhere for water, laws apply.

Snow and ice collection: In areas with cold climates, snow and ice can be collected and melted for use as drinking water – but only after it has been purified, just like any other untreated water. This method is most effective in areas with clean, fresh snow and ice.

Water Purification Tips

Here are some tips for purifying water:

Boiling: Boiling is a simple and effective way to purify water. Bring the water to a rolling boil for at least one minute (three minutes above about 2,000 metres) to kill most pathogens. Let the water cool before drinking.

Water purification tablets: These tablets contain chemicals that can kill pathogens in water. Follow the instructions on the package for the correct amount to use.

Water filters: Water filters can be used to remove contaminants from water. There are many types of water filters available, including pitchers with built-in filters, faucet-mounted filters, and portable filters.

Distillation: This method involves boiling water and collecting the steam, which is then condensed back into water. This removes most contaminants, although some volatile chemicals can carry over with the steam.

Solar still: A solar still is a simple device that can be used to purify water in a survival situation. It consists of a container of water, a smaller container to catch the purified water, and a transparent cover. Sunlight shines through the cover and heats the water, causing it to evaporate. The water vapour condenses on the cover and drips into the smaller container, leaving contaminants behind.

Safety – water borne diseases

Remember that even purified water can attract bacteria etc. if it is not properly purified or the water storage system you are using is not regularly cleaned. Read more here about keeping your water supplies clean.

Finally, this is just a brief guide to water storage and purification and any information herein is based on our own research. If stored water is not purified or stored correctly, it can transmit serious water-borne diseases to humans. So, if you are in any doubt, please seek professional help and advice.

About The Author

Article by the Prepper Weekly editor. Prepper Weekly covers practical, UK-focused preparedness – from emergency planning, power cuts and flooding to food, water, kit and outdoor skills – without the fear-mongering. Find out more about Prepper Weekly.

How Much Emergency Water Should You Store? A UK Guide To Water Storage

How much emergency water should you store?