Dams – Physical Geography

A dam or water barrier is used to control the flow of water in order to supply it for various uses, including, but not limited to water supply, flood control, irrigation, navigation, hydropower generation, trapping sediment, land drainage and wastewater management.

Hydropower generated by dams is usually referred to as “hydroelectricity”. The way in which turbines are used to generate hydroelectric power varies but in the most common design the water flows vertically downwards in a channel called a penstock. The turbine converts this flow into energy.

Uses of Dam:

1. To impound rivers and rainwater that can be used later to irrigate agricultural fields.
2. For electricity generation.
3. Water supply for domestic and industrial uses.
4. Flood control.
5. Recreation, inland navigation and fish breeding.

Side effects of Creating Dams

• Regulating and damming of rivers affect their natural flow.
• Poorer the habitats for the rivers’ aquatic life.
• Fragment rivers make it difficult for aquatic fauna to migrate.
• Dams created on the floodplains submerge the existing vegetation and soil leading to its decomposition over a period of time.
• Creating of large dams has been the cause of many new environmental movements like the ‘Narmada Bachao Andolan’ and the ‘Tehri Dam Andolan’ etc.
• Many times local people had to give up their land, livelihood and their control over resources for the construction of the dam.