How much water should you store for an emergency?
Updated October 6, 2026
Short answer
Ready.gov advises storing at least one gallon of water per person per day for several days. That gallon covers drinking and sanitation together. A household of four planning for three days would therefore set aside twelve gallons as a floor.
Where does the one gallon figure come from?
The figure is the Ready.gov guidance for emergency water. It counts drinking and sanitation in the same gallon. Ready.gov describes the amount as a minimum and asks households to plan for several days rather than a single night.
The Government of Canada works with a different unit for its own residents. It recommends two litres per person per day for drinking, cooking and hygiene. Its kit guidance assumes at least 72 hours.
Pouches or a bathtub bladder?
The shortlist covers two ways to hold that water. A bathtub bladder like the waterBOB is filled before a storm and holds up to 100 gallons. Pouches from Datrex and SOS Food Lab are single servings with a maker's shelf life. Pouches suit a kit and a bladder suits a home with warning time.
- waterBOB: a food-grade plastic bathtub bladder that holds up to 100 gallons and ships with a pump for dispensing
- Datrex Emergency Water: 64 pouches of 125 ml with a stated 5-year shelf life and USCG approval listed
- SOS Extended Life pouches: 30 pouches of 4.2 fl oz with a stated 10-year shelf life and a -22F to +149F range
Does a filter replace stored water?
The CDC says most portable water filters remove parasites but not viruses or bacteria. A filter needs an absolute pore size of 0.3 micron or smaller to also remove bacteria. Boiling clear water at a rolling boil for 1 minute kills germs according to the CDC. Above 6,500 feet it advises 3 minutes.
Stored water asks nothing of a tired household during an outage. That is the case for keeping the gallon figure as the base and a filter or boiling as the backup. Filter life and capacity figures are claims by the maker.
From our shortlist
Bathtub bladder that holds up to 100 gallons of tap water filled before a storm.
Case of 64 single-serve 125 ml water pouches with a five year shelf life.
Thirty 4.2 fl oz water pouches with a 10 year shelf life and a wide temperature range.
Related questions
How long do emergency water pouches keep?
The shelf life printed on a pouch is a claim by the maker. Datrex states 5 years for its 125 ml pouches. SOS Food Lab states 10 years for its Extended Life pouch and lists a temperature range of -22F to +149F. Both makers list USCG approval on their pages.
What does a bathtub bladder like the waterBOB do?
The waterBOB is a heavy-duty food-grade plastic bladder that sits in a bathtub. You fill it from the tap before a storm and draw water out with the included pump. The maker states a capacity of up to 100 gallons and notes that most tubs hold 60 to 70 gallons.
More questions
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