How to Build a 7-Day Emergency Water Supply

Step 1: calculate your seven-day starting amount

Number of people × 7 days × 1 gallon = starting supply.

This is not a guarantee of comfort and should not be divided into rigid drinking and hygiene quotas for every person. Individual needs vary. Think of it as the amount to establish first, then increase it for your household’s actual risks.

Water weighs about 8.3 pounds per gallon before the container. A four-person starting supply weighs roughly 233 pounds, so distribute containers on stable surfaces and avoid shelves or floors not suited to the load.

Add the needs the basic formula misses

• Pets: base the reserve on normal daily consumption, then add spill and heat margin. Ask a veterinarian about unusual species or medical needs.
• Infants: store water appropriate for feeding and sanitation and follow current formula instructions. Ready-to-feed formula may reduce reliance on water during an emergency.
• Medical needs: include water for medications, wound care, equipment cleaning, or other clinician-directed use.
• Heat and exertion: increase drinking-water capacity rather than assuming the basic amount is enough.
• Private wells: store the full supply even if you own a generator; equipment or fuel can fail.

Step 2: build a practical container mix

There is no single ideal container size. A resilient supply uses more than one container so a cracked cap or contaminated opening does not affect everything.

Step 3: prepare home-filled containers

CDC recommends FDA-approved food-grade water-storage containers when available. Follow the container manufacturer’s cleaning instructions. CDC’s general sanitizing method uses a solution made with unscented bleach containing 5%–9% sodium hypochlorite, ensures it contacts all interior surfaces, and then drains it before filling with safe water. Use the current CDC directions rather than improvising a stronger mixture.

Do not reuse milk or juice jugs as a primary long-term supply: residue and hard-to-clean seams can support contamination, and the plastic may not tolerate extended storage. Never use any container with an unknown history.

Step 4: choose safe storage locations

• Keep water away from gasoline, pesticides, paint, cleaning chemicals, and strong odors.
• Avoid direct sunlight and high heat, which can damage containers and packaging.
• Protect containers from freezing and from floodwater.
• Store on a clean, stable surface; protect containers from sharp edges and pests.
• Do not stack beyond the manufacturer’s instructions.
• Keep part of the supply accessible if a closet, basement, or garage becomes unreachable.
• Place a small mobile supply with evacuation equipment; large reserves may have to remain behind.

Step 5: label, rotate, and inspect

Follow the printed date and storage directions for commercially bottled water. For home-filled containers, CDC emergency-kit guidance commonly recommends replacing the supply every six months. Label each container with the fill or treatment date and use a recurring calendar reminder.

Inspect more frequently if containers face temperature swings or possible damage. Do not drink from a leaking, unsealed, swollen, discolored, or suspicious container. When in doubt, replace it.

Step 6: protect the supply during an emergency

• Open one container at a time, starting with the most portable or oldest appropriate unit.
• Keep hands, cups, and utensils out of the container opening; pour or use a clean dispenser.
• Do not return unused water to the storage container.
• Separate drinking and food-preparation water from lower-quality sanitation water.
• Use disposable tableware when appropriate to reduce washing.
• Follow official boil-water, do-not-drink, or do-not-use notices exactly.

Boiling and disinfection can kill many germs but do not remove every chemical. Never attempt to make fuel- or chemical-contaminated water safe by boiling it.

Seven-day setup checklist

• □ Calculate the starting gallons for every household member.
• □ Add pets, health needs, infants, and climate margin.
• □ Select food-grade containers in liftable sizes.
• □ Clean and sanitize home-filled containers using current CDC directions.
• □ Fill with safe water, seal, and date each container.
• □ Divide the supply among at least two protected locations.
• □ Store a clean pump, spigot, or dispensing method if needed.
• □ Add low-water sanitation supplies.
• □ Schedule inspections and rotation.
• □ Practice one no-tap-water meal and cleanup.

Frequently asked questions

Is 28 gallons enough for a family of four?

It is the seven-day starting amount based on one gallon per person per day. Add capacity for pets, heat, medical needs, infants, and greater sanitation demand.

Should all 28 gallons be in one barrel?

No. A mixed system is easier to carry and gives redundancy. A stationary barrel can supplement smaller portable containers.

Can I store water in the garage?

Only if the containers are protected from heat, freezing, chemicals, pests, vehicles, and damage. An interior cool, dark location is generally easier to manage.

Can a filter replace stored water?

No. A filter needs a source to treat and may not address every contaminant. Stored safe water is the dependable first layer.

Sources

Baseline quantities follow Ready.gov water guidance and its emergency-kit checklist. Container selection, cleaning, labeling, and storage practices follow the CDC emergency water supply guide and CDC safe-storage guidance. Emergency treatment limitations follow CDC instructions for making water safe.