Survival & Preparedness

Emergency Water Storage: How Much You Really Need

Water is the most important thing to store for an emergency. You can survive weeks without food. Without water, you have about three days. Yet most families do not have even one day's supply set aside.

This guide tells you exactly how much water to store, the best ways to store it, how to purify water in an emergency, and how to keep your supply fresh.

How Much Water Per Person?

FEMA and the American Red Cross both recommend one gallon of water per person per day. Half for drinking and half for cooking and basic hygiene.

In hot weather or during physical activity, you may need more. Nursing mothers, children, and sick people also need extra water. A safe planning number is 1.5 gallons per person per day if you want a comfortable margin.

Do not forget pets. Dogs need about 1 ounce of water per pound of body weight per day. A 50-pound dog needs about half a gallon daily.

Best Water Storage Containers

Not all containers are safe for water storage. Here are your options from smallest to largest.

Store-Bought Bottles

The simplest option. Cases of bottled water are cheap, sealed, and ready to use. They last 1 to 2 years unopened. The downside: they take up a lot of space and create plastic waste. Good for short-term storage (3 days to 2 weeks).

Stackable Water Bricks (3.5 gallons each)

These are rectangular, food-grade plastic containers that stack like bricks. They are easy to carry, easy to store, and fit on shelves. Eight bricks give you 28 gallons (one week for a family of four). Great for safe rooms.

5-Gallon Jugs

Food-grade 5-gallon jugs are a good middle ground. They hold enough water to be useful but are still light enough to carry (about 40 pounds full). Use BPA-free, food-grade plastic only.

55-Gallon Drums

A single 55-gallon drum holds almost two weeks of water for a family of four. These are the standard for serious preparedness. Use food-grade blue polyethylene drums. You will need a hand pump or siphon to get water out. Keep them off bare concrete (use a wooden pallet) to prevent leaching.

Large Water Tanks (200–500+ gallons)

For underground bunkers, large water tanks are the best option. A 500-gallon tank gives a family of four about four months of water. These tanks can be built into the bunker design. We include water storage planning in every bunker project.

How to Treat Water for Storage

If you are filling containers with tap water, you need to treat it first to prevent bacteria growth. The EPA recommends these methods:

• Chlorine method: Add 1/8 teaspoon (8 drops) of unscented household bleach per gallon. Let it sit for 30 minutes. You should smell a faint chlorine odor. If not, add another 8 drops and wait 15 more minutes.
• Already chlorinated tap water: If your city water is already chlorinated, you can fill clean containers directly. It will stay safe for 6 months to 1 year.
• Water preserver concentrate: Commercial products like Water Preserver keep stored water safe for up to 5 years.

Emergency Purification Methods

If your stored water runs out, you need a way to make found water safe to drink. Keep at least two of these methods in your survival kit:

• Boiling: Bring water to a rolling boil for 1 minute (3 minutes above 6,500 feet elevation). This kills bacteria, viruses, and parasites. It does not remove chemicals.
• Water purification tablets: Chlorine dioxide tablets kill 99.9% of pathogens. One tablet treats 1 liter. Wait 30 minutes before drinking. These weigh almost nothing and last 5 years sealed.
• Portable filters: Gravity filters and pump filters remove bacteria and parasites. Some also remove viruses. A Sawyer filter can clean up to 100,000 gallons.
• UV purifiers: Battery-powered UV pens kill pathogens in 60 seconds per liter. They need batteries or charging, so have a backup method too.

Where to Store Water

Water is heavy. One gallon weighs 8.3 pounds. A 55-gallon drum weighs about 460 pounds full. Plan your storage location carefully.

• Ground floor or basement: Best for heavy containers. The floor can handle the weight.
• Safe room: Keep a 3 to 7 day supply inside for quick access.
• Underground bunker: The ideal location. Cool, dark, and the structure supports heavy tanks.
• Avoid: Direct sunlight, freezing temperatures, and areas near chemicals or pesticides.

Rotation Schedule

Stored water does not go bad, but the containers can break down over time. Here is a simple rotation schedule:

• Store-bought bottles: Replace every 1 to 2 years.
• Tap water in containers (untreated): Replace every 6 months.
• Tap water in containers (treated with bleach): Replace every 12 months.
• Water with commercial preserver: Replace every 5 years.
• Large tanks with circulation system: Test annually, treat as needed.

When you rotate, use the old water for plants, cleaning, or pets. None of it goes to waste.

Common Mistakes

• Storing water in milk jugs: Milk proteins are almost impossible to fully clean out. Bacteria will grow. Use food-grade water containers only.
• Storing water next to chemicals: Plastic can absorb fumes from gasoline, pesticides, and cleaning products. Keep water away from all chemicals.
• Storing on bare concrete: Concrete can leach chemicals into plastic containers over time. Put a board or pallet underneath.
• Not having a backup purification method: Containers can break. Supply can run out. Always have tablets or a filter on hand.