Public resistance to large hydroelectric dams in India has compelled the government to provide subsidies for so-called green energy projects, such as run-of-the-river power generation. Such works, popularly referred to as mini-hydel projects, are increasing in number and are potentially threatening wildlife and habitats. One area where mini-hydel projects are being implemented is the Western Ghats of Karnataka. This biodiverse area harbours sizeable populations of threatened species such as the tiger and Asian elephant, and endemic species such as the lion-tailed macaque, Ceylon frogmouth and Travancore flying squirrel. The forests of the Western Ghats are one of the main water catchments in India, feeding perennial rivers that sustain a human population of 350–400 million in the south of the country.
Run-of-the-river power generation is presumed to be environmentally friendly but the impacts of these projects in ecologically sensitive areas are yet to be assessed. Studies of individual projects have documented a number of negative effects on terrestrial and aquatic ecosystems. Although these projects are relatively small their cumulative impact can be considerable, especially if there are numerous projects, such as in the Western Ghats of Karnataka where 72 such projects have been permitted.
Run-of-the-river projects with a power generation capacity capped at 25 MW are eligible for government subsidies. Only above 25 MW is there a compulsory public hearing and an Environmental Impact Assessment prior to construction. To bypass these legal requirements some large single projects have masqueraded as multiple smaller projects. There is also evidence of failures to document the presence of rare, threatened or unique species of flora and fauna where the projects have been implemented, even when species under various schedules of the Wildlife Protection Act 1972 were present.
To halt the detrimental effects of some of these projects Prashant Yavagal, a wildlife enthusiast, and the Western Ghats Environment Forum filed a Public Interest Litigation in the High Court of Karnataka on 3 January 2011. In February 2013, based on ecological evidence presented by the petitioners, such as the location of projects in important wildlife habitats and elephant migratory corridors, the occurrence of threatened species, felling of old-growth trees and cutting of roads on steep slopes (which results in severe soil erosion), the state government withdrew permission formerly given to 10 projects. Later, in April 2013, the existing leases of two projects were cancelled. The government indicated in the court that mini-hydel projects would no longer be permitted within the forests of the Western Ghats of Karnataka. This is a landmark case in a country where there is great pressure for development and enhanced energy generation.
Scientific and technical inputs for the litigation were provided by the Nature Conservation Foundation and Panthera, and several conservation enthusiasts worked collectively to highlight the impacts of these projects on the local wildlife.