How Much Water Should You Store Per Person?
Water is the first thing to run out and the hardest to improvise. A household can eat oddly for a week without consequence; it cannot go without water for more than a couple of days. It is also bulky enough that people postpone storing it, which is why the actual figure matters.
Where does the one-gallon figure come from?
It is the standing recommendation from Ready.gov and echoed by the CDC: one gallon per person per day, for drinking and basic sanitation combined. Roughly half is assumed for drinking and half for washing, food preparation and hygiene.
It is a floor rather than a target. The guidance explicitly notes that individual needs vary with age, health, physical condition, activity, diet and climate, and that children, nursing mothers and sick people may need more than the baseline.
How many days should you store?
Three days is the published minimum for a basic kit. Many emergency management agencies now suggest a two-week supply for sheltering at home, on the reasoning that major regional events routinely disrupt supply for longer than 72 hours.
For a family of four, three days is 12 gallons and two weeks is 56. The second figure is what makes people stop reading, and it is why a staged approach works better: store three days properly, then extend as space allows rather than treating the full target as all-or-nothing.
How should water be stored?
Commercially bottled water in its original sealed container is simplest and keeps longest. If storing your own, use food-grade containers, clean them thoroughly, and replace the water periodically. Keep containers in a cool dark place away from petrol, pesticides and other chemicals.
Storage location matters more than people expect. Water stored beside solvents or fuel can absorb vapours through permeable plastic, and containers left in sunlight encourage bacterial growth. A cool interior cupboard beats a garage shelf next to the lawnmower.
What about pets and other needs?
Add water for pets, typically calculated by their size and normal daily intake, and consider medical needs such as equipment that must be cleaned. Households with infants should account separately for formula preparation, which needs safe water in known quantities.
The commonly forgotten category is sanitation beyond hand washing. Flushing a toilet manually takes a substantial volume, and households that planned only for drinking discover this within a day of losing mains water.
Key takeaways
- Store at least one gallon per person per day for drinking and sanitation.
- Three days is the published minimum; two weeks at home is increasingly advised.
- A family of four needs 12 gallons for three days and 56 for two weeks.
- Commercially sealed bottled water is the simplest and longest-lasting option.
- Account separately for pets, infant formula and toilet flushing.
Frequently asked questions
- How long does stored water last?
- Commercially bottled water carries a manufacturer date and is generally considered safe well beyond it if sealed and stored properly, though quality can decline. Home-filled containers should be replaced periodically. Rotating stock on a schedule you will actually keep matters more than the exact interval.
- Can you drink water from the hot water tank?
- Often yes. A household water heater holds a substantial reserve that is usually safe to drink if the tank is not contaminated. Turn off the power or gas and the water supply first, then draw from the drain valve. This is a recognised emergency source in official guidance.
- Is a water filter a substitute for storage?
- Only if you have a source to filter. A filter is valuable and worth owning, but it does not create water. Storage covers the case where taps are dry and no safe source is reachable, which is exactly the scenario most guidance is written for.
- Does the recommendation change in hot climates?
- Yes. Official guidance notes that climate is one of the variables affecting individual need, and hot conditions increase requirements substantially. Households in hot regions should plan above the one-gallon baseline rather than treating it as sufficient.
Household Emergency Preparedness, BigBalli. We follow Ready.gov, FEMA, CDC and Red Cross guidance and keep it usable offline. General preparedness information, not emergency advice for a live incident.