India's Northeast has been identified by New Delhi as the country's future 'powerhouse', and Arunachal Pradesh is slated to be the major contributor. In 2001, the country's Central Electricity Authority did a preliminary ranking of the hydroelectric potential of various Indian rivers. It identified 168 large projects in the Brahmaputra Basin alone, which collectively could generate more than 63,300 megawatts of hydropower. Out of these projects, as many as 87 were in Arunachal Pradesh.
Subsequently, in 2003, a new hydropower initiative was launched at the national level, promising 50,000 MW of power. Under this, initial reports were prepared for 42 projects in Arunachal, out of which 19 were short-listed for further investigation. Prior to these studies, at least ten large projects in the state were either already in operation, under construction or in an advanced planning stage; since then, the number has skyrocketed. The current figure of completed, under construction and planned projects is 104, in both the public and private sector, promising a cumulative 55,556 MW of energy.
The government and other proponents of large dams in Arunachal say that the proposed projects will have advantages for everyone involved: the projects will be utilising the country's largest perennial water system to produce cheap, plentiful and renewable power for the whole country; and at the local level, these installations will offer economic benefits through power export across the country and employment opportunities, not to mention flood control.
Several unique features of Arunachal pose a challenge to this argument, however, including the state's large number of tribal communities and rich biodiversity, the existence of which makes the social and environmental costs of the dams extremely high. Perhaps more worrying is the region's geological fragility and seismic activity. Although nearly all of the Indian Northeast is considered highly prone to seismic activity, Arunachal is one of the only places in all of India that has areas in which earthquakes are rated a 'very high hazard'. This consideration takes on a dramatic twist when it is realised that one of the dam proposals calls for a structure 288 metres high. This would mean that India's tallest dam to date would stand in its seismically most active region. Even larger dams in Arunachal are also on the drawing board.