Building a Water Supply for Emergencies
How to store enough drinking water for emergencies: quantities, containers, storage, and purification methods.
Why Water Is Your Most Critical Resource
When the power goes out or a major emergency strikes, safe drinking water becomes the most critical resource of all. Without electricity, water treatment plants, pumps, and distribution systems can fail within hours. Unlike food, which can sustain you for weeks, the human body cannot survive more than three days without water.
The German Federal Office for Civil Protection and Disaster Assistance (BBK) recommends maintaining a drinking water supply for at least 14 days. With the right containers and storage conditions, building this reserve is straightforward and affordable.
The human body is roughly 60% water. A loss of just 2% of body weight through dehydration noticeably impairs cognitive function and physical performance. In a crisis, when you need to think clearly and stay active, hydration is not optional.
How Much Water Do You Need?
The standard guideline is 2 liters of drinking water per person per day for drinking and basic cooking. For hygiene — washing hands, basic sanitation — add another 2–3 liters per day.
For a 14-day supply for a household of four, you need at minimum 112 liters for drinking alone. With hygiene included, that rises to 200+ liters.
Additional factors to consider:
- Pets: Dogs and cats need roughly 50–100 ml per kilogram of body weight daily
- Elderly or ill persons: Medications and fever can significantly increase fluid requirements
- Infants and young children: Higher relative water needs per body weight than adults
- Physical labor: Doubling water intake during heavy activity is common
Quick Reference Table
| Household Size | Minimum (14 days, drinking only) | Recommended (incl. hygiene) |
|---|---|---|
| 1 person | 28 liters | 56 liters |
| 2 persons | 56 liters | 112 liters |
| 4 persons | 112 liters | 224 liters |
Choosing the Right Containers
Not all containers are suitable for long-term water storage. Key criteria: food-safe material, opaque or protected from light, airtight seal, and structurally stable.
Recommended container types:
- Food-grade PET water containers (5–20 liters): The most practical option — affordable, stackable, and widely available. Look for the food-safe recycling symbol. Avoid colored containers; dyes can leach into water.
- Glass bottles: Chemically inert and odor-neutral. Disadvantage: heavy and breakable.
- Stainless steel jerricans: Durable and taste-neutral, but expensive and heavy.
- Collapsible water carriers: Space-saving when empty, less durable over time.
Containers to avoid:
- Repurposed milk or juice jugs — residues promote bacterial growth
- Containers made from PVC or containing BPA (bisphenol A) — harmful chemicals can migrate into water
- Transparent containers without light protection — promotes algae growth
Storing Water Correctly
Properly stored tap water remains safe to drink for 6 to 12 months. Commercially bottled mineral water typically has a shelf life of 2 years from the bottling date.
Optimal storage conditions:
- Temperature: 10–20°C, cool and consistent. A cellar or cool closet is ideal.
- Darkness: Keep away from direct sunlight — UV light promotes algae and bacterial growth.
- Dry and clean location: Store containers upright, not directly on the floor.
- Rotation: Use older stock first, replace with fresh water behind it (FIFO principle).
Label each container with the fill date. Inspect your supply every 6 months. If water smells or tastes unusual, discard it.
Water Purification in Emergencies
If your stored supply runs out or you need to use alternative water sources, purification is essential. Rainwater, stream water, or pool water can be made safe — but never drink untreated water from an unknown source.
Method 1: Boiling The most reliable method. Bring water to a rolling boil for 1 minute (3 minutes at altitudes above 1,000 meters). Kills bacteria, viruses, and parasites. Let cool and transfer to clean containers.
Method 2: Water purification tablets Chlorine-based tablets (e.g., Micropur Forte, Aquatabs) or iodine tablets are compact and perfect for emergency kits. Follow dosage and contact time instructions exactly.
Method 3: Water filters Hollow-fiber filters (e.g., LifeStraw, Sawyer Squeeze) reliably remove bacteria and protozoa. Important limitation: they do NOT protect against viruses. In most European contexts this is acceptable, but in uncertain situations, combine with purification tablets.
Method 4: Distillation Effective even against chemical contamination. Boil water, capture and condense the steam. Labor-intensive but highly reliable.
Warning: Saltwater and chemically contaminated water (e.g., near industrial sites) cannot be made safe with household filters or tablets. Do not rely on these methods when the contamination source is unknown.
Getting Started Today
Building a water supply does not require a single large purchase. Start small: buy six extra 1.5-liter bottles of mineral water on your next grocery trip. That covers one person for nearly five days.
Expand your supply incrementally. Rotate regularly. Add purification methods — tablets and a portable filter — to cover scenarios where your stored supply is insufficient. The investment is modest; the peace of mind is significant.
