The pool of water created by the construction of a dam across a river is called reservoir. When the reservoir remains in water supply during the rainy season and releases it during dry period as per requirement, it is called storage or impounded reservoir.
The storage reservoir is generally constructed on the notion – a perennial river which cannot supply water during the summer season with the storage reservoir, the flow of water in the river is regulated.
The various purposes for which the storage works are required are
- Irrigation
- Hydro-electric power generation
- Domestic and industrial water supply
- Control of destructive floods
- Low water regulation for generation
- Recreation
- Preservation and breeding of useful aquatic life
The reservoirs which serve one more than one purpose are known as single or multi-purpose reservoirs respectively.