The large dams being built on the rivers of the eastern Himalayas have become highly controversial. The hydropower that north-east India is expected to produce is meant almost entirely for use elsewhere. That these dams will be exclusively hydropower and not multipurpose dams and that there will be a great unevenness in the distribution of potential gains and losses - and of vulnerability to risks - accounts for a serious legitimacy deficit in India's ambitious hydropower development plans in the region.