How Much Water to Store for an Emergency (UK)
GOV.UK says 3 litres per person per day for 3 days. Here’s how much that is for your household, how to store it and how long it keeps.
GOV.UK advises storing 3 litres of drinking water per person per day, for 3 days. That is 9 litres for each person in your home, plus extra for cooking, washing, baby formula, medical devices and pets.
Based on official GOV.UK Be Ready guidance.
How much water your household needs
- 1 person: 9 litres of drinking water.
- 2 people: 18 litres.
- Family of 3: 27 litres.
- Family of 4: 36 litres.
- Family of 5: 45 litres.
- Add a few litres per day for each pet, and more for washing and cooking if you can.
The best ways to store it
Sealed bottled water is the simplest option. It is clean, easy to rotate into everyday use and usually has a best-before date a year or more away.
If space is tight, a food-grade water container holds 20 litres in one stackable unit. Fill it from the cold mains tap, keep it somewhere cool and dark, away from chemicals, and refresh it regularly. Replacing stored tap water every 6 months is a sensible rule of thumb.
GOV.UK also suggests keeping purification tablets or a way to boil water as a backup, and a water butt for flushing toilets. Never drink rainwater.
If the water goes off
- Check your water company’s website for updates and bottled water stations.
- Use stored water only for drinking, handwashing and preparing food.
- Wash hands in a large clean bowl with soap to save water.
- Use ready-made baby formula if possible.
Frequently asked questions
How much water should I store per person UK?
GOV.UK advises 3 litres of drinking water per person per day for at least 3 days, so 9 litres per person, plus extra for cooking and washing.
How much water should a family of 4 store?
At least 36 litres of drinking water for 3 days, plus extra for cooking, washing and any pets.
How long can you store tap water UK?
Tap water stored in a clean, sealed, food-grade container somewhere cool and dark is generally fine for around 6 months. Replace it on a regular schedule.
Is bottled water better than tap water for emergencies?
Sealed bottled water lasts longer and is the easiest to rotate, but stored tap water in proper containers is cheaper and saves space.
If anyone is in immediate danger, call 999.