Water Storage at Home
Water is simultaneously the most important item in any emergency kit and the one most often missing, and the reason is physics: it is heavy, bulky, and it does not fit neatly anywhere.
Thirty-six litres — three days for a family of four — weighs 36 kilograms and occupies most of a cupboard shelf. Which is precisely why pre-made kits omit it and why households quietly skip it.
The solution is not heroic storage. It is small containers in several places, a date written on them, and a rotation habit that costs no thought.
The 10-minute version
- 3 litres per person per day, three days minimum. Nine litres each — about 36 litres for a family of four, which is one supermarket trolley.
- Small containers beat large ones for most households. A 20-litre drum is 20 kilograms and unliftable for many people; six-litre bottles are manageable and can live in four places.
- Rotate every six months. Anchor it to daylight saving so you never have to remember a date.
How much
| Household | 3 days (drinking) | 7 days | 14 days |
|---|---|---|---|
| 1 person | 9 L | 21 L | 42 L |
| 2 people | 18 L | 42 L | 84 L |
| Family of 4 | 36 L | 84 L | 168 L |
That is drinking water only. Add cooking, washing and flushing — which can be non-potable — and a filled bath covers most of it. More in heat, and more for anyone pregnant, unwell or breastfeeding. Pets need their own allowance.
The realistic target for most households: three days of drinking water stored permanently, plus a plan to fill the bath and every container the moment a warning is issued.
What to store it in
Good options:
- Supermarket 6 L or 10 L bottles. Cheap, food-grade, manageable weight, and they can be distributed rather than stacked in one place. The best default.
- Purpose-made 20 L jerry cans with taps. Excellent for a garage or car, heavy when full.
- 40 L drums with taps. Good value per litre for houses with space.
- A bathtub bladder. Turns a bath into 100 litres of clean stored water rather than bath water. Underrated for apartments and flood-prone homes.
- Rainwater tank, if you have one — but know that most have electric pumps that fail with the power. Fit a gravity tap.
Poor options:
- Thin single-use bottles left for years. They degrade, split and leak.
- Anything that held something else. Milk containers harbour residue; chemical containers are never safe.
- Glass, which breaks in exactly the events you are storing for.
- Containers too heavy for the person who will need to move them. A 20 L drum is unusable for many people.
Where it goes
- Split the store across several places — a cupboard, under a bed, the laundry, the car boot, the garage. One flooded or inaccessible location does not then take everything.
- Somewhere cool and dark. Heat and sunlight degrade plastic and encourage growth.
- Off concrete floors if you can — put a board or piece of cardboard underneath, since some plastics can pick up flavours over long contact.
- Reachable in the dark, and liftable by whoever is home.
- In an apartment, store it upstairs. Lifts fail with the power, and carrying water up eight flights is not a plan.
Rotation, made automatic
- Write the date on every container in permanent marker when you fill or buy it.
- Rotate every six months, anchored to daylight saving.
- Rotate by using it, not by pouring it away: water the garden, fill the kettle, fill the dog’s bowl. Then refill immediately.
- Commercial bottled water has a best-before date rather than a hard expiry; the plastic and the taste degrade before the water does.
- Tap water in clean, sealed, food-grade containers kept cool and dark stores well for six months without treatment.
Treating stored water, if you want to
For most households, six-monthly rotation makes treatment unnecessary. If you want longer storage:
- Boiling at the point of use handles anything biological. See How to Find and Purify Water.
- Water preserver drops or chlorine-based treatments designed for storage extend it, following the packet dosing.
- Do not add pool chlorine or general-purpose bleach with additives, fragrances or thickeners.
- A filter is not a storage solution. It is for treating uncertain water at the point of use.
What actually goes wrong
There is no water. The most common gap in any household kit.
All of it is in one 20-litre drum nobody can lift.
It has been there four years in a thin bottle, and now tastes like the bottle.
It is stored in a garage in an apartment building where the lift fails.
It is stored on a hot western wall in full sun.
Nothing is dated, so nobody knows whether to trust it.
Only drinking water is planned for, and then the toilet cannot be flushed.
Rainwater is assumed available, but the pump needs power.
Nothing gets filled at the warning. Four minutes, free, and skipped.
Thresholds
| Situation | The rule |
|---|---|
| Minimum store | 3 L per person per day, three days. 9 L each |
| Container size | Small enough for the smallest adult to carry. 6–10 L is the sweet spot |
| Rotation | Every six months, anchored to daylight saving |
| Dating | Written on every container in marker |
| Storage location | Split across several places, cool, dark, reachable in the dark |
| Apartments | Upstairs, not in a basement or garage |
| Any storm or fire warning | Fill the bath, sinks, pots and every container immediately |
| Rainwater tank | Fit a gravity tap. Assume the pump fails |
What it costs
| Tier | Spend | What it buys |
|---|---|---|
| Free | $0 | Refilled clean bottles you already own, dated, plus filling the bath when a warning is issued |
| Solid | ~$15–35 | 36 L of supermarket bottled water for a family of four — one shop, one trolley, done |
| Better | ~$60–140 | Two 20 L jerry cans with taps, or a 40 L drum, plus a permanent marker and a board to stand them on |
| Best for apartments | ~$40–80 | A bathtub bladder — 100 L of clean water, stored flat, deployed in minutes |
| Long term | $1,500–5,000 | A rainwater tank with a gravity tap. Worth it if you garden or live regionally; slow payback in a suburb |
The drill: the twenty-minute setup
- Five minutes. Count the people and pets in the house and calculate three days. Write the number down.
- Five minutes. Look at what containers you already have that are food-grade and sound.
- Five minutes. Fill and date them, and put them in two or three separate places.
- Three minutes. Add the shortfall to the next shopping list — supermarket 6 L bottles are the simplest fix.
- Two minutes. Set two calendar reminders for daylight saving: rotate water, check batteries.
Then, once, practise the warning routine: fill the bath, the trough, the sinks and every pot, and time it. Knowing it takes four minutes makes you far more likely to do it.
Frequently asked questions
How much water should I store for an emergency?
Three litres per person per day for drinking, minimum three days — nine litres each, or about 36 litres for a family of four. Store washing and flushing water separately, and fill the bath when a warning is issued.
What is the best container for storing water?
Food-grade containers small enough for the person who will carry them: six or ten litre supermarket bottles for most households, or 20 litre jerry cans with taps for a garage or car. Avoid glass, thin single-use bottles for long storage, and anything that held another product.
How long does stored water last?
Tap water in clean, sealed, food-grade containers kept cool and dark stores well for about six months without treatment. Rotate on a six-monthly schedule anchored to daylight saving, using the water rather than tipping it out.
Do I need to treat stored water?
Not if you rotate every six months. For longer storage, use a purpose-made water preserver following the packet dosing, and boil at the point of use if you have any doubt. Never use pool chlorine or scented household bleach.
Where should I store water in an apartment?
Upstairs, inside the unit, split between two locations — not in a basement or garage, because lifts fail with the power and carrying water up stairs is not realistic.
Can I rely on my rainwater tank?
Only if you can get water out without power. Most tanks use an electric pump that stops in an outage, so fit a gravity-fed tap at the bottom and know where it is.