1. Dams are generally built for the purpose of hydroelectricity, irrigation, water storage, flood control, etc.

2. Dams are classified according to structure, intended purpose or height.

3. Based on structure and the materials used, dams are classified as timber dams, embankment dams or masonry dams, with several subtypes.

4. According to the height, dams can be categorised as large dams and major dams or alternatively as low dams, medium height dams and high dams.