MS Menon
The Pioneer
December 10, 2014
The proposed river projects by the Chinese have raised concerns. India does not have any water-sharing agreement with China except for a joint declaration for sharing hydrological data, which is not adequate to address concerns.
After years of continued denial on its plans to construct projects on the Brahmaputra river (Yarlung Tsangpo) in Tibet, China has now confirmed the completion of the Zangmu dam in the middle reaches of the river, for which construction had begun in 2010.
According to a recent report in China’s official Xinhua news agency, the first generating unit of the $1.5 billion hydropower station (510MW) has become operational and five other stations are expected to be completed next year.
Zangmu is the first of the four projects planned by the Chinese authorities on the Brahmaputra to harness the power potential of the river. The proposed projects have raised many concerns for India though China has been repeatedly assuring us that its projects being small run-of-the-river schemes, would not have any impact on the downstream areas as they have taken a ‘responsible attitude’ to cross border development.
China has every right to build dams in their territory and we cannot dispute their right to do so. But what should actually worry India is the adverse effect of these projects on the downstream flow pattern. China can control upstream river flow to suit its hydropower generation and irrigation demands.
Presently, India does not have any water-sharing agreement with China except for a joint declaration for sharing hydrological data, which is not adequate to address these concerns. Hence, we have to be prepared to meet the situations arising out of these developments and we need to take suitable action.
One anticipated impact on India because of these projects is likely the reduction in downstream flow during the lean season (October-April) which would adversely affect our power generation schemes. According to the studies, the non-monsoon yield of the river at our project site is 33 billion cubic metres of which 22 billion cubic metres is contributed by the Chinese catchment, which amounts to about 70 per cent.
Hence if they hold up this water, water availability for our projects would be reduced drastically necessitating partial closure of the projects during this period. Also if the Chinese operate their projects indiscriminately, it would cause heavy water level fluctuations in the downstream stretch, necessitating our small projects to shut down.
Another impact due to the Chinese projects is the possible downstream flooding in Arunachal Pradesh and Assam due to simultaneous release of heavy flow of water from the upstream projects either due to safety considerations or otherwise.
Our experience in the year 2000 due to floods in the Brahmaputra caused by the failure of a blockage across the river channel in Tibet should be an eye-opener in this regard. Also since most of our strategically important cities are located on the south bank of the river, when the river is flooded, our links to the north bank will get severed. Thereby, from defence point of view, this will affect, the logistic support to our borders with China in Arunachal Pradesh.
At present, there is no major storage dam on the Brahmaputra in our territory. If we have one such dam, storage will be made available and we will be able to deal with the reduction in flows during the lean season and also prevent water level fluctuations in the river to facilitate our projects. Further, the capacity provided could absorb heavy floods as and when they occur due to the Chinese reservoir operations.
In the wake of the 2000 floods, experts had proposed a high dam with a storage capacity of about 16 billion cubic metres across the Siang (Brahmaputra) which could facilitate generation of 10,000MW power. However, it appears that the Centre has ignored this high dam project due to pressure from some environment and other lobbies and is only proposing to take up two small projects.
It is needless to stress the need for a high dam project across the Brahmaputra in view of the damming spree being planned by our neighbour in their reach of the river. Though China has been assuring us that their projects would not cause any harm on downstream river flow, we have to remain prepared to face adverse situations as and when they occur.
The project would be strategically important to provide logistic support to our border areas in Arunachal Pradesh. It is necessary to fast track the needed clearances for expeditiously implementing the project as is being done for the border roads.
Instead of opting for constructing two small capacity dams with limited storage to appease the self appointed environmentalists and activists, India should construct the Siang high dam project urgently to face the threats from liquid bombs surreptitiously being built across the Brahmaputra by our neighbour.
(The writer is a former Member Secretary, Indian National Committee on Irrigation and Drainage, Central Water Commission)
