Interruptions may be for only a short period of time, or for days. Every household should have an emergency water supply to meet its members' needs during these situations. You may be able to purchase bottled drinking or distilled water at the time of need, but stores may quickly sell out. Having an ample supply of water is a top priority in an emergency. Everyone's needs will differ, depending upon age, physical condition, activity, diet and climate.
Hot environments can double the amount needed as the body uses water for cooling.
The amount of water you need will also depend on the total amount of juices, soups, other drinks, and high moisture foods that are available. Children, nursing women, and ill people will need more. You can minimize the amount of water your body needs by reducing your activity level. Additional water will be needed for food preparation and hygiene. In general, store at least one gallon of water per person, per day of expected need.