How much water do you need?

After a storm, flood or other disaster, the water from your tap may stop running or be unsafe to drink for a while. Having your own supply means one less thing to worry about.

The basic amount

Store 1 gallon of water per person per day, for at least 3 days. That is 3 gallons for each person in your home. Roughly half of each gallon is for drinking and the rest is for basic hygiene and food.

You will need more for:

• children, nursing mothers and people who are sick
• hot weather, when everyone drinks more
• pets
• cooking dried foods

If you have space, storing more than 3 days' worth gives you a bigger cushion.

Store-bought or tap water?

Commercially bottled water is the easiest choice. It is sealed and dated, and gallon jugs make it simple to count: one jug is one person's water for one day.

Tap water in your own containers costs very little. Use food-grade water storage containers with tight lids, available from outdoor and hardware stores. Don't reuse milk or juice jugs, which are hard to clean and can break down. Fill the containers from the cold tap, label them with the date, and replace the water every six months.

A large barrel or stackable containers work well for bigger households if you have room in a garage or basement. Keep them off bare concrete by standing them on a wooden pallet or board.

Where to keep it

Keep water in a cool, dark place out of direct sunlight. Store it away from gasoline, pesticides, cleaning supplies and anything with a strong odor, because plastic can absorb smells and chemicals.

Keeping it fresh

• Set a calendar reminder to check your water every six months.
• Use the oldest bottles first and put new ones at the back.
• Replace any container that is damaged, leaking or cloudy.

If you run low

Listen for instructions from your local officials or water utility. If you are told to boil your water and can't, water purification tablets or a portable filter can help. Always follow the manufacturer's directions.