11 hydropower projects can be executed in Tawang basin: Govt

As many as 11 hydropower projects with a total capacity of about 2,700 MW can be implemented out of the 13 planned in the Tawang river basin in Arunachal Pradesh, subject to strict environmental safeguards and mitigation measures, says a government study.
However, the other two hydropower projects 'Tsa chu-I' and 'Thingbu chu' with a combined capacity of over 100 MW should not be implemented due to their possible impact on biodiversity-rich forests and mountain ecosystems, it added.
The study 'Perspective plan for development of Tawang river basin' was commissioned by Arunachal Pradesh government to assess the impact of 13 hydropower projects planned in the basin following the direction from the Centre's Forest Advisory Committee.

The study, conducted by the North-Eastern Hill University, was carried out for two years and the final report was submitted in June 2015.
"No human population or habitation will be displaced due to implementation of the proposed projects since all the projects are run-of-the river schemes and do no involve the creation of reservoir. However, the unique biodiversity, undisturbed high forests, and rich cultural diversity of Tawang River Basin will be affected if these projects are implemented," the study said.
"Therefore, a balanced approach needs to be worked out with an aim to optimise power production with minimum environment damage. This approach has to be at a basic scale considering all the proposed projects, rather than following a single project approach," it said, adding that hydropower is the least polluting source of power generation among the major sources of energy production.

Among key recommendations, the report highlighted that the two hydropower projects -- Tsa chu-I and Thingbu chu -- should not be implemented because they have high cumulative impact at river basin level as compared to other 11 projects.

The study further said that 11 hydropower projects should be implemented in two phases.
Of these, six projects -- Nykcharong chu, Tawang-I, Tawang-II, Nyamjang chu, Jaswantgarh Stage-I and Paikangrong chu -- should be implemented in the first phase (0-5 years). The rest five projects -- Rho, New Melling, Mago chu, Tsa chu-I Lower and Tsa chu-II -- in the second phase (5-10 years), it added.

The study also suggested mitigation measures to minimise the adverse impacts of 11 projects in Tawang river basin.
According to the study, the projects proposed above 3200 metre elevation should not be implemented in the river basin. Under this criteria, the Tsa Chu-I project cannot be implemented as it is proposed at an elevation of 3,295 metre.
Further, the projects above 2,500 metre have to follow strict environmental safeguards and adopt specific mitigation measures, subject to fulfilling of other conditions, it said.
The environmental flow or e-flow of the river should be maintained by all the proposed projects -- Nykcharong chu, Tawang-I, Tawang-II, Rho, Mago chu, New Melling, Tsa chu-I Lower and Tsa chu-II, it added.