To the surprise of many, the need for water is much higher than for food. Many people have lived for 30 days with no food, but without water, after three or four days you are in serious trouble. People tend to underestimate how much water is actually needed to perform normal, routine tasks of daily living. Drinking water is the primary need, but you may need additional water for baths, cooking, flushing toilets, cleaning eating utensils, washing clothes and other chores.
Water availability is affected in natural and man made disasters.
In every disaster, the majority of the general population is totally unprepared for even a small interruptions in normal utility and food distribution services. There are myriad ways the water supply can be disrupted. The most common way is due to lack of electricity. The second most common way is a water main rupture. Recently, more than 10,000 people in the southeastern United States were out of water for over two weeks due to such a rupture.