Abstract
This report describes the concept of the minimum demand for water from the sanitary point of view, and introduces the necessity of this study, definition and basic concept of the minimum demand for water, meaning and application of estimating the minimum demand for water, kind of water usage and research theme, collection of data through literature survey, selection of the items for examinations, survey with questionair and estimation of minimum demand for water. In this paper, the level of water usage are divided in four steps, like in emergency, urgency, ordinary uses and rich uses. The paper also refer to the water saving and effective use of water. If one is able to clear the limit volume of water considering the level to keep one's life and household sanitation in an emergency and urgency (which is so called minimum demand for water), design data for daily load can be estimated rationally by multiplying it with the rate of margin. As the result of these estimations, the accuracy of design data are upgraded, and it should be possible to approach the limit designing.
