Emergency Water Storage: How Much to Store and How to Keep It Safe

How much water to store per person

Ready.gov and CDC guidance say to store at least 1 gallon of water per person per day. Half of that is for drinking and half is for cooking and basic hygiene like washing hands and dishes. That is a floor, not a comfortable amount.

The common target is a two-week supply, which works out to about 14 gallons per person. A household of four should aim for roughly 56 gallons. Store more if you live in a hot climate, since heat and sweat drive up how much you drink, and more for anyone who is pregnant, sick, or nursing. Do not forget pets, which need water too.

• At least 1 gallon per person per day (Ready.gov and CDC guidance)
• Aim for a two-week supply: about 14 gallons per person
• A family of four: roughly 56 gallons for two weeks
• Add more for hot climates and for pregnant, sick, or nursing people
• Plan a little extra for pets

Use food-grade containers only

Store water only in food-grade containers, meaning plastic made without dyes or recycled resins that can leach into what you drink. Commercial bottled water in its original sealed jugs is the simplest option and needs no prep. For bulk storage, use food-grade water barrels or 5- to 7-gallon water jugs sold for camping and emergencies. A 55-gallon water barrel covers roughly one person for a month at the 1-gallon-per-day rate.

Never store drinking water in containers that once held milk, juice, or any non-food chemical. Milk and juice leave sugars and protein that feed bacteria no matter how well you rinse, and old bleach or detergent jugs hold residue. If you reuse a container, it should be one made for food or water in the first place.

• Food-grade plastic only, marked safe for food or water
• Sealed store-bought bottled water is the easiest choice
• A 55-gallon food-grade barrel is about a month for one person
• Never reuse milk, juice, or chemical containers

How to store tap water safely

Tap water from a treated public supply is already disinfected, so you can store it as-is without adding anything. Wash the container and lid with hot soapy water, rinse well, then fill it to the top so little air is left inside. Cap it tight and label it with the date.

Keep stored water in a cool, dark spot away from sunlight, which breaks down plastic and can let algae grow. Keep containers off bare concrete on a shelf or wood, since plastic can pick up flavors and chemicals from a garage floor over time. If your water comes from a private well or is not treated, disinfect it before storing using the steps below.

• Clean the container, fill to the top, cap tight, and date it
• Store cool, dark, and out of direct sun
• Keep containers off bare concrete, on a shelf or board
• Disinfect untreated or well water before storing

How long stored water keeps and how to rotate it

Water itself does not go bad, but the container and any stray microbes do change over time, so stored water needs rotating. For tap water you bottle yourself, replace it about every 6 to 12 months. Commercial bottled water carries a best-by date from the maker, which is more about bottle quality and taste than safety, but rotating by that date is a good habit.

The simple system is first in, first out: use your oldest water first and refill with fresh. Mark every container with the fill date so you can tell at a glance what to use next. If stored water ever looks cloudy, smells off, or has anything growing in it, do not drink it. Treat it or throw it out.

• Rotate self-filled tap water about every 6 to 12 months
• Follow the best-by date on store-bought bottled water
• Use oldest first (first in, first out) and refill with fresh
• When in doubt about how it looks or smells, treat it or toss it

How to purify water in an emergency

If you run out of stored water and have to use a questionable source, you have three main tools: boiling, bleach, and filters. Boiling is the most reliable. Bring water to a rolling boil for 1 minute, or 3 minutes if you are above 6,500 feet elevation, then let it cool before drinking. Boiling kills bacteria, viruses, and parasites.

If you cannot boil, you can disinfect clear water with plain unscented household chlorine bleach. The widely published CDC ratio for bleach that is 6 percent sodium hypochlorite is about 8 drops, roughly 1/8 teaspoon, per gallon of clear water, doubled for cloudy water. This is safety-critical: the correct amount depends on the exact strength of your bleach, so read the bleach label and follow the CDC page on making water safe exactly rather than guessing. Stir it in, then let it sit 30 minutes. The water should have a faint chlorine smell.

Filters are the third tool. A good gravity or pump filter removes bacteria and parasites, but many do not remove viruses on their own, so pair a filter with boiling or bleach when the source is sketchy. If the water is cloudy or muddy, let it settle and strain it through a clean cloth first, since dirt shields germs from both bleach and filters. Follow CDC guidance for treating water; when in doubt, boil it.

• Boil at a rolling boil for 1 minute (3 minutes above 6,500 feet)
• Bleach: use plain, unscented household chlorine bleach only
• Follow the CDC page for the exact bleach amount and your bleach's strength
• Filter cloudy water and strain out dirt before treating
• This is general information, not medical advice