The uses of water include drinking, washing and cleaning, cooking, transportation, providing hydroelectric power, irrigation and recreation. Living beings need water to move nutrients into their cells and to help them excrete wastes and toxins. Water is necessary in many chemical reactions and laboratory tests. Water is also necessary for many medical procedures, including dental treatments and dialysis.
Water is useful to fight fires and is important in construction work. Concrete, for example, is made of cement and other materials mixed with water. Water has use as a coolant in manufacturing, industry and agriculture. Both livestock and crops need great volumes of water for survival, and crops need water to deliver fertilizer and insecticides.
Long before the industrial age, people used water as a source of energy. The first machine to use water was most likely a platform built beside a stream that was attached to a bladed wheel. The water fell on the blades and turned the wheel. Old-fashioned water mills still use water this way.
Later, people built dams to catch and store flood waters. This guaranteed a supply of water, even during droughts. Dams also raised the water level, which provided more power. In the 19th century, water served as a source of power for electric generators.