Water is the most essential of all nutrients. Water is necessary for many physiological functions, including regulation of temperature, transport of nutrients, excretion of wastes, lubrication, and virtually every metabolic reaction in the body. Water is considered the most consumed nutrient by the pig in terms of amounts throughout its lifetime. Consequently, water deprivation exerts a dramatic impact on feed consumption, limits growth and feed efficiency, and reduces milk production in lactating sows. Thus, it seems to be of utmost importance to provide water in enough quantity and adequate quality to swine in any stage of production. At the same time, it is becoming increasingly important to minimize water wastage in swine production.