The devastating floods that hit Uttarakhand in 2013 were widely blamed on ambitious development projects, but the state is still going ahead with a plan to generate more than 21,000 megawatts of electricity from about 180 big and small hydroelectric projects along 11 tributaries of the Ganges river.
Writing in a June 2014 issue of Current Science, K. S. Valdiya, honorary professor of geodynamics at the Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore, pointed to the plan’s failure to appreciate the region's vulnerability.
The earth’s crust is made of “tectonic plates” which are constantly moving. The Indian subcontinent is part of a tectonic plate that is moving northward, bumping into and sliding under the Eurasian plate. The Himalayas are located in a ‘fault’ where the two plates meet.
“Unless dams are designed to withstand earthquakes, there are dangers of them getting disconnected from their support structures,” says Valdiya. “Even small tampering with the precarious balance, such as digging for house-building and quarrying can have an adverse effect on slope stability.”
Tank Ojha, a University of Arizona researcher working in the Nepal Himalayas, tells SciDev.Net that “one proposed dam known as West Seti which has a capacity to produce over 1,100 megawatts of electricity sits right on the active fault”.
Maharaj Pandit, who heads the department of environmental studies, University of Delhi, says the fact that the Himalayas are home to several endemic species should have been factored in while planning to build hydroelectric dams.
As an alternative, Valdiya recommends a network of smaller, cheaper dams that generate 6—12 megawatts each. Since the Himalayas are areas of high wind, dams can be supplemented by wind turbines in integrated projects. But, there are disagreements.
“For smaller projects, the impacts of the associated infrastructure development can sometimes be higher than the impacts of the project itself,” says Shripad Dharmadhikary, founder of Manthan Adhyayan Kendra, a centre located in Badwani, Madhya Pradesh state, that researches water-related issues.
“Wind projects, which are single installations spaced at large distances, need road networks through fragile areas,” Dharmadhikary adds.
> Link to the paper in Current Science
This article has been produced by SciDev.Net's South Asia desk.