How Much Water Should You Store for an Emergency?
Store at least one gallon per person per day for several days. How much your household needs, how to store it safely and how to treat unsafe water, per Ready.gov and CDC.
Plan on one gallon of water per person per day, and store enough for at least three days. That's the baseline Ready.gov, the federal government's preparedness site, gives for drinking and basic sanitation. For a family of four, that's 12 gallons as a bare minimum, and a lot of households will want more.
Most people never think about this until the tap stops working, and by then the store shelves are usually empty. A burst water main, a winter storm that knocks out power to a pump station, a boil-water notice after a flood: all of them leave you with water you can't safely drink. Setting aside a few cases of bottled water or some clean jugs takes an afternoon and costs very little.
How much water do you actually need?
The one-gallon rule covers drinking and a little washing. Ready.gov says a normally active person needs about three-quarters of a gallon of fluid a day, and the rest of the gallon goes to things like brushing teeth and cleaning up. It also warns that needs go up for children, nursing mothers, sick people and anyone living in a hot climate, where water needs can double in very high temperatures.
| Household | 3 days (minimum) | 7 days (safer) | 14 days (what many preparedness groups suggest) |
|---|---|---|---|
| 1 person | 3 gallons | 7 gallons | 14 gallons |
| 2 people | 6 gallons | 14 gallons | 28 gallons |
| 4 people | 12 gallons | 28 gallons | 56 gallons |
Ready.gov's own guidance is "several days," so the three-day column is the official floor. The longer columns are simple multiplication, and they're our suggestion rather than a federal rule. If you have a baby, a sick family member or pets, add to the total.
What's the best way to store emergency water?
The easiest option is also the one Ready.gov recommends first: buy commercially bottled water and leave it sealed in its original container, in a cool, dark place. It doesn't need any prep and the bottles stack neatly in a closet or under a bed. Check the printed date on the case and swap it out when it passes.
If you'd rather fill your own containers, use food-grade water storage containers, not old milk jugs, which break down and are hard to get fully clean. Ready.gov's steps are short:
- Wash the container with dish soap and rinse it well.
- Sanitize it with a solution of one teaspoon of plain, unscented household bleach in a quart of water.
- Fill it with clean tap water, cap it tightly, and write the date on it.
- Replace water that wasn't commercially bottled every six months.
Keep containers off bare concrete if you can, away from gasoline, paint thinner or other chemicals, and out of direct sun. Don't put all your water in one spot. If a pipe bursts or a basement floods, you'll be glad some of it is upstairs.
What water should you never drink?
Your home holds more usable water than you'd think, though the CDC is clear about what to avoid. Check your local alerts first, and count ice in the freezer as part of your supply. What you should never drink is water from radiators or boilers that are part of a home heating system, the CDC says, because it could make you sick.
If a notice says your tap water is contaminated, though, treat everything from that system as unsafe until officials say otherwise. Local alerts come through your county emergency management office or city website, so look up yours now rather than during the outage.
How do you make unsafe water safe to drink?
Stored water can run out. The CDC lists several ways to treat questionable water, and boiling comes first because it's the most reliable:
- Boil it. Bring clear water to a rolling boil for one minute, or three minutes above 6,500 feet. Let it cool and keep it in clean, covered containers. If the water is cloudy, strain it through a clean cloth or coffee filter first.
- Use bleach. For plain bleach at 5 to 9 percent sodium hypochlorite, the CDC says to add a little less than one-eighth teaspoon per gallon (about 8 drops), stir, and wait at least 30 minutes. Double the amount if the water is cloudy or very cold. Check the label first, since bleach strength varies.
- Filter and disinfect. Portable filters don't remove viruses. The CDC says to add a chemical disinfectant after filtering.
- Distill it. Ready.gov notes that distillation also removes salts, heavy metals and most chemicals, which boiling doesn't.
One important limit: boiling or bleach can't fix water contaminated with fuel or toxic chemicals. For that, the CDC says to use bottled water or another source and call your health department.
Do you need a special water system?
Not to get started. A few cases of bottled water and a couple of clean jugs meet the federal baseline. Some people want to go further, with larger tanks or a plan for long-term supply. There are paid guides for that. One is the Water Freedom System, a digital do-it-yourself guide we've listed as an option. It's an affiliate link (#ad), so we may earn a commission if you buy through it, at no extra cost to you.
We haven't tested it, and we're not repeating the seller's promises as fact. The honest pros and cons: it may give you ideas for larger setups and it's a one-time digital download, but it covers things you can find free from Ready.gov and the CDC, and results will depend on your home, climate and local rules. Read the seller's refund terms yourself before you buy. See the Water Freedom System (#ad).
Wondering about the date on the bottles you already own? See does bottled water expire.
A simple weekend checklist
- Count people and pets, then multiply by 3 gallons for your starter supply.
- Buy bottled water or clean food-grade containers, and date each one.
- Store them in two or more places, cool and out of the sun.
- Keep plain unscented bleach and a dropper or measuring spoon with them.
- Set a phone reminder for six months out to rotate homemade water.
Water is just one piece of readiness. Because the cost of heating is rising too, our guide on lowering your electric bill this winter is a good companion read, and you can browse more explainers on the site.
Frequently asked questions
How much water should I store per person?
Ready.gov says at least one gallon per person per day for several days, covering drinking and sanitation. Children, nursing mothers, sick people and anyone in a hot climate may need more.
How long does stored water last?
Commercially bottled water can stay in its sealed original container in a cool, dark place until the date on the package. Ready.gov says water you bottle yourself should be replaced every six months.
Can I use old milk jugs or soda bottles?
Food-grade water containers are the better choice. Ready.gov advises using food-grade containers, cleaning them with dish soap and sanitizing with a diluted bleach solution before filling.
How much bleach do I add to purify water?
The CDC says that with 5% to 9% household bleach, you add a little less than one-eighth teaspoon per gallon, stir, and wait 30 minutes. Double it if the water is cloudy or cold, and follow the label if it gives directions.
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