A dam is a hydraulic structure of fairly impervious material built across a river to create a reservoir on its upstream side for impounding water for various purposes.
Dams are classified according to their structure, intended purpose or height.
On the basis of structure and material used, dams are classified as:
- Timber dams
- Embankment dams or masonry dams.
According to their height, dams can be categorised as:
- Large dams or major dams
- Low dams
- Medium height dams
- High dams
