WHAT ARE DAMS FOR?

A dam is a man-made obstacle to naturally flowing water built for one or more of the following purposes : 

• Storing water for farm irrigation, hydro-electricity­, water supply to town or industry, prevention of flooding, maintaining the water level in the highest reaches of canals, etc.  
• Raising the water level to provide a head which can be turbined in an electricity generating powerstation at the dam toe, or to divert the river flow into a canal, tunnel or pipeline. 
• Forming an artificial lake for navigation, leisure, activities, etc. 
• Preventing water from the downstream side moving inland to protect farmland against seawater encroachment, maintain a reserve of fresh water in an estuary, create polders for land reclamation, etc.