Water is the single most important item in any emergency plan, and it’s also the one most people underestimate. You can go weeks without food, but only about three days without water. The good news: figuring out how much you need is simple arithmetic.
The rule of thumb: one gallon, per person, per day
The commonly cited guideline from Ready.gov (the U.S. government’s preparedness program) is to store at least one gallon of water per person per day — roughly half for drinking and half for cooking and basic hygiene. Ready.gov recommends a minimum three-day supply for evacuation and a two-week supply for staying home.
Do the math for your household
Take your rule of thumb and multiply:
- People in your home × 1 gallon × number of days = total gallons.
- Example: a family of four planning for 3 days needs 12 gallons. For a 2-week supply, that’s 56 gallons.
Add more if you have pets, someone who is pregnant or nursing, anyone with a medical condition, or if you live in a hot climate where you’ll sweat more.
How to store it safely
- Use food-grade containers. Commercial bottled water or containers sold specifically for water storage are simplest.
- Keep it cool and dark. Heat and sunlight degrade both the water and the container over time.
- Rotate it. Store-bought sealed water has a printed date; label anything you fill yourself and refresh it periodically.
- Have a backup purification method — such as unscented household bleach (a few drops per gallon, per EPA guidance) or a dedicated water filter — in case you need to treat questionable water.
The bottom line
You don’t need a bunker. You need a number and a shelf. Run the multiplication above, buy or fill enough containers, and you’ve solved the most critical part of emergency prep in an afternoon.
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