Live storage
Also called: Live storage capacity · Topic: Water Resources of India: Availability, Use and Conservation · NCERT: Beyond NCERT
Meaning
Live storage is the part of a reservoir's water that can be let out and used. It lies between the lowest outlet of the dam and the reservoir's full level. Engineers draw on this water for irrigation, drinking water and hydropower. If they keep this space partly empty before the monsoon, it can also hold back floodwater. Live storage, rather than the size of the dam, shows how much a reservoir can really supply or control. Silt that settles in the reservoir over the years slowly takes up this space and shrinks it.
Example
The proposed Siang Upper Multipurpose Project on the Siang (Brahmaputra) in Arunachal Pradesh is reported to have about 9.2 billion cubic metres of live storage. The river carries about 112 billion cubic metres a year at the dam site, so the reservoir could hold less than one-tenth of a year's flow.
Don't confuse with
- Dead storage: the water below the lowest outlet. It cannot be released by gravity, so it stays in the reservoir and slowly fills with silt.
- Gross storage: the total volume of the reservoir up to full level. It equals live storage plus dead storage.