A water mill uses moving water as its power source. Usually, it uses the power to drive a mechanical process such as grinding, rolling, or hammering. These processes can produce material goods such as flour, paper, lumber, textiles, and metal products. Water-driven wheels have been around since the third century BC. By the early 20th century, as inexpensive electrical energy became available, water mills became obsolete. This 19th century vintage water mill is at the Shoal Creek Living History Museum in Kansas City, Missouri.