Cupboard · What you keep · 3 min read
How much water per person per day in an emergency?
Plan for 2.5 to 3 litres of drinking water per person per day, the World Health Organisation survival minimum quoted by GOV.UK's Prepare campaign (checked 26 Aug 2026). Nine litres per person covers three days. For basic cooking and hygiene as well, allow 10 litres per person per day.
The slightly longer answer
The government’s Prepare campaign quotes the World Health Organisation: a minimum of 2.5 to 3 litres of drinking water per person per day is required for survival, while 10 litres per person per day also covers basic cooking and hygiene (checked 26 Aug 2026). Three days is the sensible planning unit, so keep 9 litres per person.
That works out like this for a whole household:
| People in the house | Drinking only, three days (3 L a day) | Drinking, cooking and hygiene, three days (10 L a day) |
|---|---|---|
| 1 | 9 litres | 30 litres |
| 2 | 18 litres | 60 litres |
| 3 | 27 litres | 90 litres |
| 4 | 36 litres | 120 litres |
| 5 | 45 litres | 150 litres |
Nobody stores 120 litres in a flat, and you don’t need to. Keep the drinking-water column in sealed bottles, and plan to cover the rest by filling pans, jugs and the bath while there is still pressure, as set out in what to do when the water goes off. Practical containers and where to keep them are covered in water storage.
Water is the one item in the home emergency kit that runs out in hours rather than days, which is why it earns the most cupboard space.
Related questions
Does 3 litres a day include washing and cooking?
No. The 2.5 to 3 litre figure is drinking water only, described by the guidance as the survival minimum. The 10 litres per person per day figure is the one that also provides for basic cooking and hygiene. Treat 3 litres as the floor, not the target.
Is 9 litres per person really enough?
It covers three days at the survival minimum, which sees out the vast majority of interruptions. Longer ones do happen: in late 2025, around 24,000 homes near Tunbridge Wells were on bottled water or a boil notice for about two weeks, as reported at the time (South East Water’s incident page covers the event). [VERIFY: exact figures — South East Water/DWI incident report] Storing more than 9 litres is never wasted.
What should I store water in?
Sealed shop-bought bottles are the simplest: cheap, clean and dated. Keep them somewhere cool and dark and swap them at a big shop before their best before date. A couple of empty, lidded containers are worth keeping too, for carrying water from a bowser or tanker. See water storage.
Do pets need their own water allowance?
Yes, though the official guidance doesn’t set a figure for animals. Keep an extra bottle or two on top of the household numbers, scaled to the size of the pet. During a boil water notice, the Drinking Water Inspectorate’s advice is that pets should get boiled and cooled or bottled water, like people.
Sources & review
- UK Government, Prepare campaign: Get prepared for emergencies. Checked 26 August 2026. The 2.5–3 litre WHO survival minimum and the 10 litres per person per day comfort figure.
- South East Water: Boil notice for customers in Tunbridge Wells. Checked 26 August 2026. The company’s own page for the 2025 incident; scale and duration figures are as reported at the time.
- Drinking Water Inspectorate: Receiving a boil water notice. Checked 26 August 2026. Boiled and cooled water for pets during a boil notice.
Awaiting editorial review (reviewedBy: TBC).