How much water to store for emergency preparedness, which containers are safe to use, how to store water correctly, and how often to rotate your supply.
Water is the most critical survival supply. The human body can survive weeks without food but only days without water, and in hot weather, strenuous conditions, or for people who are ill, the requirement is significantly higher. Municipal water supplies are vulnerable to contamination, infrastructure failures, flooding, power outages (most water treatment requires electricity), and chemical accidents. A stored water supply is not a luxury — it is a practical preparedness measure.
This article covers how much water to store, what containers are safe and practical, how to prepare and fill those containers, and how to maintain your supply so it remains safe when you need it.
The baseline recommendation is 3.8 litres (1 US gallon) per person per day. This covers:
| Duration | Per Person | Family of 4 |
|---|---|---|
| 72 hours (3 days) | 11.4 litres | 45 litres |
| 1 week | 26.6 litres | 106 litres |
| 2 weeks | 53 litres | 212 litres |
Increase your estimate by 50% for:
The CDC recommends 3-days minimum; FEMA recommends 2 weeks minimum for serious preparedness. In practice, store what space and budget allow.
⚠️ The per-person quantities above do not include cooking water, which can add 1–2 litres per person per day depending on diet. If you plan to cook meals from stored dry or freeze-dried food, factor in the rehydration requirement.
Not all containers are safe for long-term water storage:
| Container Type | Safe? | Notes |
|---|---|---|
| HDPE (High-Density Polyethylene) — Food Grade, marked with HDPE or "2" recycling symbol | Yes | Best choice; does not leach; available in purpose-made water containers |
| Purpose-built emergency water barrels (50L, 100L, 200L) | Yes | HDPE; purpose-made for this; large volume |
| WaterBOB or similar bathtub bladder | Yes | For filling a bathtub to store temporarily during an emergency; not for long-term storage |
| Food-grade glass containers | Yes | Heavy; fragile; but does not leach |
| Commercial bottled water (original sealed bottles) | Yes | Convenient but expensive per litre; limited lifespan |
| Aluminium bottles (food-grade, clean) | Yes | Good if empty and clean |
| Milk containers (plastic) | No | Milk proteins remain in the plastic; impossible to clean fully; bacteria grow |
| Bleach or chemical containers | No | Contamination risk; plastic may be the wrong type |
| Cardboard containers | No | Not waterproof; contaminates water |
| Non-food-grade plastic | No | Leaches chemicals |
| Containers previously used for non-food substances | No | Contamination risk |
For municipal (mains) tap water:
If filling from a well or other non-treated source:
| Requirement | Detail |
|---|---|
| Cool | Heat degrades plastic and accelerates chlorine dissipation; aim for < 25°C |
| Dark | UV light degrades plastic and can affect water quality |
| Away from chemicals | Petrol, solvents, cleaning products — plastic is porous to some vapours |
| Off the ground | Floor-level storage risks contamination from flooding; also easier access |
| Accessible | You need to reach your water quickly; do not bury it under other stored goods |
Stored water does not last indefinitely:
| Water Source | Recommended Replacement Interval |
|---|---|
| Municipal tap water in clean HDPE containers | Every 6–12 months |
| Commercial bottled water (sealed) | Up to stated expiry; typically 1–2 years |
| Well water (treated with bleach) | Every 6 months |
| Water in bathtub bladders | Use within 72 hours of filling |
Rotation method: Use a "first in, first out" approach. When you fill new containers, move old ones to the front for daily use first. Alternatively, use stored water for normal cooking and drinking and replenish; this ensures continuous turnover.
Signs that stored water has gone off:
If in doubt: treat before drinking (boil for 1 minute or use a filter and disinfection), or discard.
For 2-week preparedness, individual 2L or 5L bottles are impractical in terms of space and cost. Options for higher volumes:
| Option | Volume | Practical Notes |
|---|---|---|
| 5-gallon (18L) water jugs with dispenser | 18L | Stackable; dispenser makes access easy |
| 55-gallon (200L) HDPE drum | 200L | Sufficient for one person for ~50 days; needs a pump or siphon |
| 30-gallon (115L) drum | 115L | More manageable size |
| WaterBrick stackable containers (3.5 gallon) | 13L per unit | Stackable; compact; expensive per litre |
Drums require a manual pump or siphon for practical access. Include this with the drum when purchasing.
| Need | Detail |
|---|---|
| Minimum storage | 3.8L per person per day; 3-day minimum |
| Recommended storage | 2 weeks minimum |
| Container choice | HDPE food-grade; NOT milk containers |
| Fill from tap | Clean; sanitise container; label with date |
| Storage conditions | Cool, dark, off the ground, away from chemicals |
| Rotation interval | Every 6–12 months for tap water |
| Signs of deterioration | Cloudy; smell; discolouration |
| Hot weather multiplier | Add 50% to base quantity |
Take Water Storage — Containers, Quantities, and Rotation with you — no internet needed when it matters most.
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