Hydroelectric projects in India's Eastern Himalayas risk damaging this world biodiversity hot spot, which is home to many endangered species. Government agencies should scrupulously assess the environmental impact of such huge projects before approving them.
For example, estimates suggest that there are currently fewer than 300 freshwater South Asian river dolphins (Platanista gangetica gangetica) in the Brahmaputra River and its tributaries. Of the 170 or so dams that are planned or under construction there, some will change the river's morphology and hydrology, degrading or destroying the deep pools that form the dolphins' natural habitat and further endangering these rare mammals (see A. Wakid Curr. Sci. 97, 1143–1151 (2009); see also M. K. Pandit et al. BioScience http://doi.org/wqm; 2014).
The dams' cumulative impact on downstream wetland and floodplain ecosystems also threatens Kaziranga National Park in Assam, which hosts the world's highest density of endangered Bengal tigers (Panthera tigris tigris) and a major population of Indian rhinoceroses (Rhinoceros unicornis).
Likewise, the Kurichu dam on the Manas River and the Mangdechhu dam on the Mangde River in Bhutan pose a threat to the Manas Wildlife Sanctuary in Assam, which was on the World Heritage Committee's danger list as recently as 2011.