Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online.A water wheel is a machine for converting the energy of flowing or falling water into useful forms of power, the development of hydropower. In the Middle Ages, waterwheels were used as tools to power factories throughout different counties. The alternatives were the windmill and human and animal power. The most common use of the water wheel was to mill flour in gristmills, but other uses included foundry work and machining, and pounding linen for use in the manufacture of paper.