Drinking water, also known as potable water, is water that is safe to drink or to use for food preparation. The amount of drinking water required to maintain good health varies, and depends on physical activity level, age, health-related issues, and environmental conditions. Americans, on average, drink one litre of water per day and 95% drink less than three litres per day.For those who work in a hot climate, up to 16 litres a day may be required.