The catastrophic rainfall related devastation was exclusively in the Alakananda-Bhagirathi (A-B) basins; the most intense 24-hour rainfall being 325 mm and 417 mm in Chorabari and Paontasahib (adjacent Yamuna basin). Mr. Thakkar and Ms Upadhyay acknowledge the consequent battering and land slips of the fragile slopes. Human intervention due to properly designed dams and appurtances neither lead nor led to landslips. The EAC has no role in project implementation and operation other than stipulating environmental protection measures. Slips of the generated muck (formed fills) and severe scour at flanks were a natural consequence of catastrophic downhill overland flow and flood. Operational deficiencies if any can be identified.
The mid-August Bhagirathi flood was not discussed in the paper and each flood event needs specific management, but Tehri in mid-June did reduce a downstream catastrophe. Hydro projects mentioned include a large number of minor projects (2-25MW). The large Yamuna and Lower Ganga projects received clearance almost 20 years ago. For the four operational projects (Tehri-Koteswar one complex) downstream, a riverine reach of around 40 km with power tunnels in the flanks bear the brunt of environmental impact. Clearance to the 24 projects referred by the Supreme Court will definitely be guided by the WII’s recommendation.
It is stressed that the paper contained no falsification of facts and for the past two years, the EAC, considering the cumulative impact of projects, has taken a pro-environment stand, recommending an increased monsoon release of 30 per cent, thereby sacrificing 10-20 per cent generation. Informed debate rather than animosity is a better way to approach the issue.
(Bishnu Prasad Das was Engineer-in-Chief of Water Resources, Odisha.)