Emergency water and food supply: how much to store and how

Store at least 3 days of water and food for everyone at home, and work towards 2 weeks. The CDC recommends at least 1 gallon (about 3.8 litres) of water per person per day, so a family of four needs about 45 litres for 3 days. For food, choose non-perishable items you can eat without cooking and that you already eat, such as tinned fish, meat and beans, crackers, nuts and dried fruit. Store everything somewhere cool and dark, and rotate it so nothing expires.

A water and food supply is the base layer for almost any emergency: a blackout, a flood, a contaminated water main, or a few days when shops are closed. The European Commission’s Preparedness Union Strategy (March 2025) asks every household to be able to cope on its own for at least 72 hours.

How much water: who recommends what

Agencies agree on the 3-day minimum but not on the daily amount:

Source	Per person per day	Duration
CDC, Ready.gov / FEMA, American Red Cross	1 gallon (3.8 l), drinking and sanitation	3 days minimum, 2 weeks if possible
UK government	3 l for drinking, plus extra for cooking and washing	3 days
Polish government Safety Guide	3 l minimum	at least 3 days
Government of Canada	at least 2 l	at least 72 hours

The 1-gallon figure is the most generous because it includes basic hygiene. If you can only store less, the UK and Canadian figures show what the absolute minimum for drinking looks like. The Red Cross puts the difference clearly: plan 3 days of supplies for an evacuation, and 2 weeks if you are staying at home.

The CDC asks you to store more for pregnant women, people who are ill, pets, and anyone in a hot climate.

The per-person maths

At the CDC rate of 1 gallon (3.8 litres) per person per day:

Household	3 days	2 weeks
1 adult	3 gal / about 11 l	14 gal / about 53 l
2 adults	6 gal / about 23 l	28 gal / about 106 l
4 people	12 gal / about 45 l	56 gal / about 212 l

At the UK rate of 3 litres a day for drinking only, one person needs 9 litres for 3 days and 42 litres for 2 weeks.

Pets: the Government of Canada suggests about 4 litres a day for an average dog and 1 litre a day for an average cat, for at least 72 hours.

Two weeks of water for a family takes up real space. A realistic approach is to store the 3-day minimum as bottled water, add more as space allows, and keep a way to treat water (see below) for anything beyond that.

How much food

There is no official calorie target for an emergency supply. Ready.gov asks for “at least a several-day supply of non-perishable food”, and the Red Cross suggests 3 days for evacuation and 2 weeks at home. As a benchmark, EU food labels use a reference intake of 2,000 kcal a day for an average adult. Children need less; people doing hard physical work or living through a cold winter need more.

An example day for one adult, using no-cook food:

Meal	Example
Breakfast	cereal or granola with UHT milk, dried fruit
Lunch	tinned fish on crackers, a tin of vegetables or beans
Dinner	a tinned ready meal or meat with bread or crispbread
Snacks	nuts, a protein or fruit bar, peanut butter

Multiply by the number of days and people for your shopping list. Our canned food stockpile guide works through a full week in cans.

What to buy first

Water:

Unopened commercially bottled water. The CDC calls it the safest and most reliable source in an emergency.
A water filter or purification tablets, for when the stored water runs out.

Food that needs no cooking (Ready.gov list):

tinned fish, meat, fruit, vegetables and ready meals,
protein or fruit bars, dry cereal or granola,
peanut butter, nuts, dried fruit,
crackers, crispbread, rusks,
shelf-stable (UHT) or powdered milk, tinned juice,
comfort foods, which help morale during a long disruption,
baby food and pet food if you need them.

Ready.gov advises ready-to-feed formula for babies, because mixing powder needs safe water. Plan for any special diets at home, such as allergies, diabetes or coeliac disease.

Add a manual can opener, eating utensils, disposable plates, bin bags and, if you can, a camping stove with gas canisters. Ready.gov says camp stoves and charcoal grills are for outdoor use only. Our camping stove guide covers safe use.

How to store water

The CDC’s advice for filling your own containers:

Use food-grade containers. If a container is not food-grade, it should at least have a tight lid, be made of durable, unbreakable material (not glass) and ideally have a narrow opening. Never reuse containers that held bleach, pesticides or other chemicals.
Clean and sanitise them. Wash with soap and rinse. Mix 1 teaspoon of unscented household bleach (5–9% sodium hypochlorite) into 1 quart (about 1 litre) of water, pour it in, close the lid and shake so it touches all surfaces. Wait at least 30 seconds, pour it out and let the container air-dry.
Fill with clean tap water and close tightly.
Label each container “drinking water” with the date.
Store at 50–70°F (10–21°C), out of direct sunlight and away from fuel, pesticides and other chemicals.
Replace every 6 months. For bottled water, follow the date on the label.

When you use stored water, pour it or use a clean scoop. The CDC warns against putting hands into the container.

How to store food

Ready.gov advises keeping tins in a cool, dry place and boxed food in tightly sealed plastic or metal containers, which keeps out pests and damp.
Keep food off the floor in a damp basement, and away from the oven, radiators and sunny windows.
Small flat? Under the bed, on top of the wardrobe, in a suitcase. See our guide to preparedness for renters.
Do not eat from swollen, dented or corroded cans, and discard any food that has touched flood water, as Ready.gov advises.

How to rotate so nothing goes to waste

Buy what you already eat.
Put new packs at the back and move older ones to the front.
Once a quarter, eat whatever is close to its date and buy a replacement.
Refill stored tap water every six months, for example when the clocks change.
Keep a simple list on the cupboard door: item, quantity, earliest date.

How to make water safe when the supply runs out

If your stored water runs out, or the authorities issue a boil-water notice, the CDC gives these methods. Bottled water remains the first choice.

Boiling (kills disease-causing germs):

If the water is cloudy, let it settle or filter it through a clean cloth, paper towel or coffee filter.
Bring it to a rolling boil for 1 minute. Above 6,500 feet (about 2,000 m), boil for 3 minutes.
Let it cool and store it in clean, covered containers.

Household bleach (unscented, 5–9% sodium hypochlorite, when the label has no drinking-water instructions):

Water	Bleach 5–9%
1 litre or quart	2 drops
1 gallon (3.8 l)	8 drops
5 gallons (19 l)	40 drops

Stir and wait at least 30 minutes before drinking. Double the dose if the water is cloudy, coloured or very cold.

Tablets and filters: follow the product instructions. The CDC notes that chemical tablets may not kill all parasites (iodine and chlorine tablets do not kill Cryptosporidium, chlorine dioxide does), and portable filters do not remove viruses, so combine a filter with a disinfectant.

What does not work: boiling and disinfecting cannot make water safe if it is contaminated with fuel, toxic chemicals or radioactive material. Use bottled water and ask your local health authority. Never drink water from radiators or heating boilers.

Common mistakes

Only pasta and rice. Without power or gas you cannot cook them. The first days need food you can eat straight away.
No water for washing. When the water pressure drops, fill the bath and pots immediately.
One big shop and nothing after. A supply that is never rotated starts expiring within a year.
Using containers that once held chemicals. The CDC says never to store water in anything that held bleach, pesticides or similar.
No can opener.

First step

Buy one pack of bottled water per person and three days of food you like. Add the rest on your next few shopping trips, working towards two weeks. For blackout-specific supplies, see Blackout preparedness, and for what to do with the fridge when the power goes, see food safety in a power outage.

FAQ

How much water should I store per person?

The CDC says at least 1 gallon (about 3.8 litres) per person per day for 3 days, and a 2-week supply if possible. The UK government advises 3 litres per person per day for drinking, plus extra for cooking and washing.

How long does stored tap water last?

The CDC recommends replacing tap water you store in your own containers every 6 months. For store-bought water, follow the date on the label.

What food should I stockpile for emergencies?

Food you can eat without cooking and already eat anyway: tinned fish, meat and beans, crackers, nuts, nut butter, dried fruit, bars, shelf-stable milk. That makes rotation easy.

Where should I store emergency water?

Somewhere cool and dark, away from direct sunlight, heaters, chemicals and fuel. The CDC gives a range of 50–70°F (10–21°C).

How much water does a family of four need for two weeks?

At the CDC rate of 1 gallon per person per day, 56 gallons, or about 212 litres. If that is more than you can store, keep at least the 3-day minimum of about 45 litres and a way to treat more water.

How do I make water safe to drink with bleach?

The CDC says to add 8 drops of unscented 5–9% household bleach per gallon (2 drops per litre), stir, and wait at least 30 minutes. Double the amount if the water is cloudy, coloured or very cold.

Does boiling make water safe?

Boiling kills germs: the CDC says to bring clear water to a rolling boil for 1 minute, or 3 minutes above 6,500 feet (about 2,000 m). Boiling does not remove fuel, chemicals or radioactive material.

Sources

PrepReady group on TelegramQuestions, gear and shared experience. Join the conversation.

This guide is educational. In an emergency, follow official alerts and first responders.