How to Plan Emergency Water for Your Household
How much, where to store it, and how to keep it safe.
Clean water is the first supply most households run short of. Here's how to plan it.
How much water to plan for
Plan one gallon per person per day as a baseline — roughly half for drinking and half for food preparation and sanitation. Add more for pets, heat, exertion, or medical needs. A family of four planning for three days needs at least twelve gallons; the same family planning for two weeks needs fifty-six. That is a lot of water to store, which is why most households build up gradually and pair stored water with a way to treat more.
That baseline is a planning figure for mild conditions, not a medical prescription. Hot weather, physical labor, nursing mothers, and some medical conditions all increase the amount of water a person needs. The CDC and FEMA publish the one-gallon-per-person-per-day figure as a minimum starting point; treat it as the floor, not the ceiling, and adjust for your household.
Count every person and pet. A large dog can drink as much as a person on a hot day. A cat drinks less but still needs a planned supply. If anyone in the home has a condition that requires extra fluids, plan for that too. The number on the page is only useful if it reflects the people and animals actually in your household.
Where and how to store it
Use food-grade containers designed for water storage. Avoid containers that ever held anything non-food — even a thorough wash can leave residue. Commercial water storage jugs, clean soda bottles (rinsed and sanitized), and dedicated water bricks all work. Label each container with the date it was filled so you know when to rotate it.
Store water away from direct sunlight and heat. A cool, dark, and stable location extends shelf life and keeps the container from degrading. Basements, lower closets, and under-bed storage are common choices. Avoid storing heavy water on high, unbraced shelves where a leak or a fall could cause injury.
Rotate stored water every six months. Tap water that has been properly sealed stays safe for a long time, but the CDC recommends replacing it every six months to keep it tasting fresh and to catch a container that has developed a slow leak. Mark the rotation date on your calendar or set a reminder in the maintenance tool on this site.
Treatment as a backup, not a replacement
If stored water runs low, you may need to treat water from another source. Boiling is the most reliable method when you have heat: a rolling boil for one minute (three minutes at altitude) kills the pathogens that matter most. Chemical treatment with unscented household bleach is a documented backup — follow the CDC dosage, not a guess, and use only plain unscented bleach without additives.
Filters and purifiers are different tools and it matters which you choose. A filter removes particulates and some pathogens; a purifier addresses a broader range including viruses. Match the method to the water source and its contamination type. A backpacking filter is fine for clear mountain water; it is not rated for floodwater that may contain chemicals or sewage. Read the manufacturer's instructions and know the limits of what you own before you rely on it.
Never assume any single method makes water safe in every situation. If your local authority issues a boil-water advisory, follow their guidance exactly. If water may be chemically contaminated, no household filter will make it safe — use a different source or wait for official all-clear.
Water planning checklist
- One gallon/person/day baseline (plus pets)
- Food-grade containers, each dated
- Stored away from heat and direct sunlight
- Six-month rotation reminder set
- A treatment method and its instructions on hand
- A way to collect more water from a safe source if needed
Sources & further reading
This guide is planning guidance, not emergency advice. In an emergency, call 911. See a mistake? Report it.
Related guides
Emergency Water Containers: What Matters Before You Buy
Not every jug is safe for drinking water. Here is how to choose, fill, and store containers without spoilage.
Water Filters, Purifiers, and Treatment: Know the Limits
A filter is not a purifier, and a purifier is not a guarantee. Match the method to the contamination.