The short answer
Sealed bottled water is the simplest store: keep it in its original bottle somewhere cool and dark and use it by its date. For water you fill yourself, use food-grade containers with tight lids, not glass and never one that held chemicals. Several 10 to 25 litre containers are easier to lift and fit than one big one: a full 20 litre can weighs about 20 kg. Label each with 'drinking water' and the date, keep it cool, dark and away from chemicals, and change it every 6 months, as the US CDC and Ready.gov advise. Keep one container you can carry, to fetch water from a bottled water station.
Prints the checklist without the menus.
Do this now
- Work out your total: 3 litres per person per day for 3 days (Be Ready). Our supplies calculator does it for you.
- Buy sealed bottled water first. Ready.gov says store it in its sealed original container somewhere cool and dark.
- Add one or two food-grade containers you can lift, and fill them from the tap. Label them "drinking water" with the date (CDC).
- Keep one carryable container for fetching water from a bottled water station (Krisinformation).
- Set a 6-month reminder to change self-filled water (CDC, Ready.gov) and check bottle dates.
Free: the Alert Action Card
The first six steps for a nuclear or radiation alert, a missile or air attack alert, no water from the tap and a power cut, on one page for the fridge, plus a phone version you can open offline. Every step checked against GOV.UK, UKHSA and Be Ready on 3 November 2026. No sign-up needed.
Print card (A4 PDF, light) Phone version (PDF)
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How much, and how heavy
| People | 3 days at 3 L a day (Be Ready) | Weight |
|---|---|---|
| 1 | 9 L | about 9 kg |
| 2 | 18 L | about 18 kg |
| 3 | 27 L | about 27 kg |
| 4 | 36 L | about 36 kg |
One litre of water weighs about one kilo. The CDC suggests trying to store 2 weeks if you can, which is US advice; Be Ready asks for 3 days. Store extra for babies, pets and medical devices (Be Ready).
Container types compared
The "best for" column is our view.
| Type | Typical sizes | Good | Watch out | Best for |
|---|---|---|---|---|
| Sealed bottled water | 0.5–2 L bottles, 5 L | Already clean and sealed; has a date | Bulky; plastic waste | Everyone's first store |
| Rigid food-grade can (jerry can) | 10–25 L | Tough, stacks, often has a tap | Heavy when full (20 L ≈ 20 kg) | The main home store |
| Collapsible carrier | 5–20 L | Folds flat; light | Less tough; can leak at folds | Fetching from water stations; filling when a warning comes |
| Long-life water pouches | Small pouches | Long shelf life, fits a bag | Little water per pouch | Grab bag or car |
| Rainwater butt | Varies | Free water | Not for drinking (Be Ready) | Flushing toilets, plants |
| Loft cold-water tank | The DWI suggests about 250 L for most homes | Already in many older houses | Only safe to drink if well built and maintained (DWI) | Not your drinking store unless you're sure |
What "food-grade" means: the CDC says use food-grade containers, and if you're not sure, ask the maker. If you can't get one, pick something durable and unbreakable (not glass) with a tight lid, ideally a narrow neck.
Opaque or clear? No official source we found says which. Light can encourage algae, which is why we suggest opaque containers kept in the dark. That is our advice, not an official rule.
Where to keep them
- Cool and dark. The CDC says somewhere cool, about 10 to 21 °C, and out of direct sunlight. Krisinformation says a dark, cool place.
- Away from chemicals. The CDC says away from toxic things such as petrol and pesticides. Not next to the bleach under the sink.
- Spread out, not in one spot. In a flat: multipacks under beds, a can in a kitchen cupboard, bottles in freezer gaps. More ideas in where to store water in a small flat.
- Not the loft (heat in summer, freezing in winter) and not by a radiator. This is our advice, based on the CDC temperature range.
- Within reach in the dark, with a torch nearby.
- Freezer: Krisinformation suggests freezing PET bottles as ice packs that later become drinking water. Leave room at the top so they don't crack.
Cleaning and filling your own container
The CDC's method, in metric:
- Wash the container with soap and rinse it well.
- Mix about 1 teaspoon of unscented household bleach in about 1 litre of water (the CDC's "1 quart").
- Put the lid on, shake so the solution wets every inside surface, and wait at least 30 seconds.
- Pour it out and let the container air-dry.
- Fill with tap water, close tightly, and label "drinking water" with the date.
This bleach mix is for cleaning containers only, not for treating water to drink. For that, see making water safe to drink.
Never reuse a container that held bleach, pesticides, fuel or paint (CDC). The UK Chief Medical Officers say the same for collecting water in an emergency.
How long water keeps
| Water | How long | Source |
|---|---|---|
| Sealed bottled water | By the date on the bottle | Ready.gov: keep sealed in the original container |
| Tap water you bottled yourself | Replace every 6 months | CDC; Ready.gov |
| Any stored water | "Many months" in good conditions; no exact limit | Krisinformation (Sweden) |
Krisinformation says check stored water once or twice a year by looking, smelling and tasting, and use old water on plants. Rotate bottled water into everyday use and replace it on your next shop. See stock rotation.
About loft tanks
Many older UK homes have a cold-water tank in the loft, and in some only the kitchen cold tap comes straight from the mains. The Drinking Water Inspectorate says:
- Ideally drink only from a tap connected to the mains.
- Tank water is only safe if the tank is properly designed, correctly installed and kept in good condition: a tight lid, screened vents, insulated and out of sunlight.
- If you rent, your landlord or managing agent should be able to tell you if your drinking water comes from a tank and how it's maintained.
So don't count loft-tank water as your drinking store unless you know the tank meets those rules.
Printable checklist
- Total worked out: ____ litres (3 L × people × 3 days)
- Sealed bottled water bought
- Food-grade containers, not glass, never ex-chemical
- Containers cleaned with the CDC method
- Each labelled "drinking water" and dated
- Stored cool, dark, away from chemicals
- Spread around the home, reachable in the dark
- One carryable container for water stations
- Freezer bottles have space at the top
- 6-month reminder set to change self-filled water
- Purification tablets in date, for when stores run out
What to buy
About these links: plain links to ordinary retailer pages. We may earn from some links in future; we don't now. We haven’t tested these and we don’t rank them: they are examples that were in stock when we checked. Prices change. Check what you already own first. Full kit list
Food-grade water containers with lids
Look for: Food-grade, with a lid, never one that held chemicals, fuel or paint. Date the water you store.
Bottled water
Look for: 3 litres per person per day for 3 days, for drinking. More for babies, pets and medical devices.
- Seven Oceans Emergency Drinking Water 0.5l (5-year shelf life) · EVAQ8 · £3.94 (price on 1 November 2026) Shop
Water purification tablets
Look for: In date. Follow the label: tablets come in different strengths. Filter cloudy water through a cloth first.
- Lifesystems Chlorine Dioxide Water Purification Tablets · Lifesystems (UK brand store) · £10.99 (price on 1 November 2026) Shop
- Lifesystems Chlorine Water Purification Tablets · Lifesystems (UK brand store) · £3.99 (price on 1 November 2026) Shop
- Aquatabs 397mg Water Purification Tablets (100 Pack) · Amazon UK · £53.55 (price on 1 November 2026) Shop
Water filter (optional)
Look for: Read what the maker says it removes. Keep tablets or a way to boil water as well.
- LifeStraw Personal Water Filter · Amazon UK · £25.80 (price on 1 November 2026) Shop
- LifeStraw Peak Series Solo Personal Water Filter · Amazon UK · £31.99 (price on 1 November 2026) Shop
- Lifesystems Water Filter Purifier Bottle · Lifesystems (UK brand store) · £49.99 (price on 1 November 2026) Shop
- Lifesystems Water Filter Purifier Soft Flask · Lifesystems (UK brand store) · £29.99 (price on 1 November 2026) Shop
What we couldn't check
- No UK body publishes rules for home water containers (sizes, materials, how long water keeps). We use the US CDC and Ready.gov, and Sweden's Krisinformation, and say so.
- No official source we found compares opaque and clear containers. The opaque advice is ours.
- The 250 litre figure is the DWI's suggested loft tank size for most homes, not a storage target.
Frequently asked questions
What size water container should I buy?
Work out how much you need first: Be Ready says 3 litres per person per day for 3 days, so 9 litres each. Then split it into containers you can lift. One litre weighs about a kilo, so a full 20 litre can is about 20 kg. In a flat, bottle multipacks and 10 litre cans are easier to fit and carry than one large drum.
How long can you store water in a container?
The US CDC and Ready.gov say replace water you've bottled yourself every 6 months. Sweden's Krisinformation says it can stay fresh for many months in good conditions but no one can give an exact limit, so check it once or twice a year. Use sealed bottled water by its date.
What containers should I not use?
Never a container that held bleach, pesticides, fuel, paint or other chemicals (CDC; UK Chief Medical Officers). The CDC says avoid glass and use something durable and unbreakable with a tight lid.
Is the water in my loft tank safe to drink?
The Drinking Water Inspectorate says ideally only drink from a tap connected to the mains. Water from a loft tank is only safe if the tank is properly designed, installed and kept in good condition, with a tight lid. If you're not sure, don't treat it as your drinking store.
Do I need a big water tank or IBC?
For drinking water, most homes don't. Official UK advice is 3 litres per person per day for 3 days, which fits in bottles and cans. If you collect rainwater in a butt, Be Ready says it's not for drinking, but it's useful for flushing the toilet.
Should I freeze water bottles?
Sweden's Krisinformation suggests freezing PET bottles: they act as ice packs and later as drinking water. Leave space at the top, because they can crack when they freeze.
Sources
We opened each page on the date shown. Official advice changes: if a source says something different now, follow the source.
- GOV.UK Be Ready: water supply interruptions or outages (read 2 November 2026)
- GOV.UK Be Ready: be ready for emergencies (checklist) (read 2 November 2026)
- US CDC: How to create and store an emergency water supply (read 2 November 2026)
- Ready.gov (FEMA, US): Water (read 2 November 2026)
- Krisinformation.se (Sweden): Water supply in a crisis (read 2 November 2026)
- Drinking Water Inspectorate: Water storage tanks and cisterns (read 2 November 2026)
- UK Chief Medical Officers (GOV.UK, 16 December 2025): Water and sanitation scripts for broadcast media, national power outage (read 2 November 2026)
Related guides
- Emergency water at home: how much to store and how
- No water supply: what to do, and what you're entitled to
- Stock rotation at home: first in, first out
- An emergency plan for flats: what's different, and what to ask
- Frozen and burst pipes: what to do, and how to prevent them
Free tools
- Emergency supplies calculator (how much water for your household)
- No water in my area: your water company's live page
We're an independent UK site, not the government. We check guides against official sources and link to them. In an emergency call 999.
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