Despite the fact that Hydroelectric Projects are recogonised as the most economic and preferred source of electricity, share of hydropower in the total installed capacity in India has been declining steadily since 1963. The hydro share has declined from 44 percent in 1970 to 24 % in 1999. The ideal hydro-thermal mix should be in the ratio of 40:60 and present imbalance is largely responsible for system instability. In order to reverse the trend and given the renewed thrust on hydropower by the Government, NHPC Limited has drawn up a massive capacity addition plan in hydro sector upto 2017.