🚨 Without water a human survives only 3 days. Per person and day you need 3 liters (drinking + cooking) plus 10–20 liters for hygiene. A 4-person household needs at least 56 liters per week — for drinking alone.
1. How much water to store?
| Period | Drinking water (4 pers.) | + Hygiene/sanitation | Total |
|---|---|---|---|
| 3 days | 36 L | 120–240 L | 156–276 L |
| 2 weeks | 84 L | 280–560 L | 364–644 L |
| 1 month | 180 L | 600–1.200 L | 780–1.380 L |
Federal Office of Civil Protection (BBK) recommends: at least 14 days of stock — with space constraints at least 3 days.
2. The right containers
| Container | Advantages | Disadvantages |
|---|---|---|
| PET bottles (food grade) | Cheap, stackable, leak-proof | Only 6–12 months, light damage, not reusable for long-term storage |
| HDPE canisters (blue, 10–25 L) | Food-grade, dark, stackable, lasts years | Heavy when full (25 kg), small opening |
| IBC containers (1,000 L) | Very large quantities | Heavy, space, outdoor only (UV protection needed) |
| Glass bottles | Unlimited shelf life, no plastic leaching | Fragile, heavy, expensive |
| Water tank (steel/plastic, fixed) | Large quantities, often with tap | Expensive, not portable, needs space |
Important: Only containers with food-grade approval (PE-HD recycling code 2, HDPE) or glass. Never milk/juice bottles (residues), never unmarked canisters (plasticizers/chemicals).
3. Filling: tap water suffices
- Fill tap water directly into clean HDPE canisters — no boiling needed (utility chlorination protects initially)
- Don't fill completely (leave 2–3 cm of air — for frost safety + chlorine distribution)
- Seal tightly, label with date (filling) + contents
- Store dark and cool (cellar, pantry) — UV promotes algae and bacterial growth
- Separate from chemicals: No contact with petrol, solvents, paints (vapours diffuse through plastic!)
4. Shelf life & rotation
| Storage type | Shelf life | Rotation |
|---|---|---|
| PET bottles (untreated) | 6–12 months | Drink and refill |
| HDPE canisters (tap water) | 12–24 months | Check every 6–12 months + treat if needed |
| With preservative (see below) | 5+ years | Rotation not needed, but check water |
| Chlorine/hypochlorite treated (see below) | 5+ years | Rotation not needed |
Keep rotation simple: At your next water bill, drink the stock or use it for plants and refill fresh. A calendar reminder (phone) suffices.
5. Preservation: making water last
Method A — chlorination (recommended):
- Per 1,000 L of water: 4–8 ml of unscented 12 % sodium hypochlorite solution (unscented bleach) — or ca. 1 heaped tablespoon per 100 L
- Target: 0.2–0.5 mg/L free chlorine in the water (slight smell, not stinky)
- Stir, let stand 24 hours, then seal container tightly
- Chlorine decomposes slowly — preserves the water against bacteria and algae for years
Method B — silver ions / special preparations:
- Commercial water preservation tablets (e.g. Micropur Classic) — dose according to package instructions
- Silver ions inhibit bacterial growth for years — no chlorine taste
- More expensive than chlorination, but taste-neutral
6. Treating water before use
Stored water is not always drinkable as-is — depending on storage duration and conditions:
- Smell + look: Cloudy, smelly or algae? Treat first!
- Boil (1–3 min rolling boil) — most reliable method
- Chlorinate (as above) — if boiling is not possible
- Filter (drinking water filter, e.g. activated carbon + membrane) — for cloudy water or taste problems
7. Rainwater & other sources (supplement, not replacement)
- Collect rainwater (gutter → tank) — for hygiene use (toilet, washing), not directly drinkable
- Make drinkable: filter + boil or chlorinate
- Water boiler/heating reserve: The storage tank of the hot water boiler contains 50–200 L of drinking water — drain in emergency
- Toilet cistern (without chemical additives!): 5–9 L of drinking water per cistern
8. Checklist: water storage
- ☐ HDPE canisters (2× 25 L per person, food grade)
- ☐ PET bottles as short-term reserve (6–12 months)
- ☐ IBC tank or fixed tank (optional, large quantities)
- ☐ Sodium hypochlorite (12 %, unscented) or Micropur tablets
- ☐ Labels + marker (filling date)
- ☐ Drinking water filter + spare filter
- ☐ Pot for boiling (gas/wood stove capable)
- ☐ Dark, cool storage location (cellar/pantry)
9. Did you know?
- The BBK (Federal Office of Civil Protection) recommends 3 L of drinking water + 3.5 L of household water per person/day — most households have no stock.
- In disaster exercises, water shortage is the most common critical point — without water, sanitation, hygiene and nutrition fail.
- Water from the hot water boiler and the toilet cistern is available in most apartments and can be used immediately in an emergency.