The kharif season is over and it is too late for rabi. But the people in Andhra Pradesh are praying hard for rain. They are praying because only the Rain God is capable of offering them relief from load-shedding. The reservoir levels, however, are at their lowest at this time of the year.
Nearly two-thirds of the hydel power in Andhra Pradesh is generated at Srisailam Dam Project, the largest hydro-power generating complex in the country with an installed capacity of 1,670 MW (megawatts-million watts) (and at Nagarjuna Sagar Project (815.5 MW). The total hydel power production of Andhra Pradesh is 3,734.5 MW and the combined hydel production of Srisailam and Nagarjuna Sagar is 2,485 MW.
Because of the scant rainfall in the upper reaches of the Krishna river all the major projects in its course are empty for all practical purposes.
The water in Srisailam and Nagarjuna Sagar has reached dead storage level. This means that there is no scope for generation of hydel power till this year’s rains bring water in August/September.
The capacity, volume or storage of a reservoir is usually divided into distinguishable areas. ‘Dead’ or ‘inactive’ storage refers to water in a reservoir that cannot be drained by gravity through a dam’s outlet works, spillway or power plant intake and can only be pumped out. ‘Active’ or ‘live’ storage is the portion of the reservoir that can be utilised for flood control, power production, navigation and downstream releases.
Dead storage allows sediments to settle which improves water quality and also creates hydraulic head along with an area for fish during low levels. As much as half the Srisailam Dam capacity is dead storage as there is over a 100 tmcft still in the reservoir, but not a single tmcft of water is available for power generation or agriculture.
Nagarjuna Sagar dam also has a huge amount of water in the dead storage. There is 131 tmcft in the dead storage of the reservoir and just three tmcft are available for power generation/ agriculture.
The two reservoirs had an additional 100 tmcft on the corresponding date last year. Srisailam had 14 tmcft more and Nagarjunasagar had 86 tmcft on January 28, 2012. Hydel power which is several times cheaper than thermal power is needed to keep the price of power low. The purchasing of power from other states pushes up the average cost of production which the consumer has to bear ultimately.
Hydel power is several times cheaper than thermal power
The purchasing of power from other states pushes up the average cost of production