Emergency Water Storage Guide: How to Store Enough Water
Water is the most critical emergency supply — and the most underestimated. Most households dramatically underestimate how much water they actually need. Beyond drinking, water is required for hygiene, food preparation, sanitation, and medication safety. This guide covers exactly how much to store, what to store it in, and how to ensure it stays safe.
Last reviewed: 2026-03-01 · Based on Ready.gov, CDC, FEMA guidance
How Much to Store
- Adults: 1 gallon per person per day (minimum)critical
This covers drinking + minimal hygiene. If someone is ill, in a hot climate, or doing physical work, double it.
- Children: 1 gallon per child per day (same as adults)critical
Children need the same per-pound hydration as adults.
- Infants: extra 1 gallon per day for formula preparationcritical
Do not use tap water if a boil advisory is in effect. Store extra for formula.
- Pets: 0.5 gal/day per large dog, 0.25 gal/day per catcritical
Store pet water separately from human supplies.
- Hot climate modifier: double your water storage in summer or hot climatescritical
- Target minimum: 3-day supply for rapid emergency; ideally 2 weekscritical
FEMA recommends 2 weeks for major disasters. Most households manage 3 days. Start there, build up.
Storage Containers
- Food-grade plastic containers (HDPE, #2 recycled symbol)critical
Milk jugs are NOT suitable — protein residue promotes bacterial growth and the plastic degrades. Use dedicated water containers.
- Commercially bottled water: most convenient, longest shelf life
Typically sold with a 2-year 'best by' date. Properly sealed water doesn't expire, but plastic can leach chemicals over time. Rotate every 1–2 years.
- 5-gallon BPA-free water jugs (stackable)
Best balance of capacity, manageability, and cost. Too heavy to move when full — store where you'll use them.
- WaterBob bathtub liner (100 gallons) for in-place emergency fill
Fill before a storm when tap water is still safe. One-time use — $25–30. Not a substitute for stored water.
- 55-gallon water barrel (for homes with yard/garage space)optional
Cost-effective for large households. Requires a pump and bung wrench. Store in cool, dark location.
- Water brick stackable containers (apartment-friendly)
3.5-gallon rectangular containers stack in closets and under beds.
Water Treatment & Purification
- Water purification tablets (iodine or sodium dichloroisocyanurate)
Treat questionable tap water or collected water. Follow package directions. Remove iodine taste with vitamin C tablets after treatment.
- Unscented liquid bleach for water disinfection (8 drops per gallon)
Standard household bleach (5–9% sodium hypochlorite). Use 8 drops per gallon for clear water, 16 drops for cloudy water. Let stand 30 minutes before drinking.
- Portable water filter (LifeStraw, Sawyer Squeeze, or similar)
Removes bacteria and protozoa. Does NOT remove viruses — combine with chemical treatment in areas with human contamination.
- Boiling: bring to rolling boil for 1 minute (3 minutes above 6,500 ft elevation)critical
Most effective water treatment. Works when you have fuel.
Safe Storage Practices
- Store in a cool, dark location (UV light and heat degrade containers)critical
- Keep away from gasoline, pesticides, and chemicals (plastic absorbs fumes)critical
- Rotate stored tap water every 6 months; bottled water every 1–2 yearscritical
Label with fill date. First In, First Out.
- Do not store water directly on concrete floors (gas transfer through plastic)
Use a wooden pallet or plastic shelving.
What to Do If Your Stored Water Runs Out
- Know when your municipality issues boil advisories (check local emergency website)critical
- Rainwater collection: legal and useful in most states, but requires treatment before drinkingoptional
- Swimming pool water: can be purified with bleach; note higher chlorine content already presentoptional
- Water heater tank: most contain 30–80 gallons of clean water
Drain from the bottom valve. Turn off power/gas first. Best to drain before sediment mixes.
- Ice in the freezer: melts into safe water if your home water supply was safe
Detailed Guidance
Calculating Your Household's Total Storage Need
Example calculation (3-day supply): 2 adults + 1 child + 1 dog: - Adults: 2 people × 1 gal/day × 3 days = 6 gallons - Child: 1 × 1 × 3 = 3 gallons - Dog: 1 × 0.5 × 3 = 1.5 gallons - Total: 10.5 gallons Same household, 7-day supply: 24.5 gallons Storage equivalent: - 10.5 gallons = about 11 one-gallon jugs, or 2 five-gallon jugs + spare - 24.5 gallons = five 5-gallon jugs For 7-day supply with comfortable margin, most 2-person households need 4–5 five-gallon jugs. Note: these are minimums. Add 50% in hot climates or for physically demanding scenarios. Source: Ready.gov
Signs Your Water Isn't Safe to Drink
During and after a disaster, your tap water may be unsafe even if it looks clear. Red flags — do not drink tap water if: - Your area has issued a boil advisory (check local emergency management website or reverse 911) - You see or smell sewage backup - Flooding has occurred in your area (flood water contains sewage, chemicals, and pathogens) - Your pipes may have been broken or flooded - You notice discoloration, cloudiness, or unusual odor When in doubt, boil or treat all water before drinking or using for food preparation. A boil advisory from your utility is the official signal. Even "safe-looking" water during a flooding event can contain E. coli, Giardia, or chemical contaminants. Source: CDC
Related Resources
Emergency Kit Calculator
Auto-calculates water quantities for your household size.
72-Hour Kit Calculator
Quick water calculation for your go-bag.
Apartment Emergency Prep
Compact water storage solutions for small spaces.
Flood Preparedness Checklist
Water contamination during floods — what to do.
Power Outage Checklist
Water pumping may fail during extended outages.
Emergency Contact Sheet
Include your water utility emergency number.