ARE NEPAL AND INDIA AIMING TO KILL KOSI HIGH DAM PROJECT?
Dr. A.B. Thapa
Very recently the Kosi river has again started to show its ugly face by unleashing a reign of terror against the peoples living in the vast flood plain of this river. The present shifting of the Kosi channel to the east could be the beginning of a new cycle of Kosi flood disasters All top experts on Kosi agree that it is indispensable to provide large storage dams to regulate the Kosi river if the life and property of millions in Nepal and India are to be protected. But it is terribly shocking that we are now going to kill the Kosi dam projects.
Indo-Nepal Joint Team
In 1997 an agreement was signed between Nepal and India to conduct detailed feasibility studies of the storage dams to control the Kosi river, along with detailed feasibility study of a navigation canal linking Nepal with the seaport. Already a joint Indo-Nepal technical team is conducting feasibility studies. Amidst all these activities the Government of Nepal is now seen deliberately moving in the direction to preclude forever the possibility to implement the Kosi dam projects. A complete silence from the side of the Government of India on this vital issue at this time, when the Indian water experts stationed in Nepal already for quite some time know every detail of the Kosi basin dam projects, leads everybody to believe that the Indian side too sees nothing wrong with our Government’s decision. It is explained hereinafter how the Kosi dam projects would be permanently obstructed if our Government’s decision is not reversed. It is hoped that all concerned authorities will take this matter very seriously.
Permanent Obstruction
Arun, Tamar and Dudh-Kosi are tributaries of the Kosi river. Our Government is soon going to give license to private developers to implement the Lower Arun and Tamar-1 projects. Similarly private developers are being repeatedly invited to apply to obtain license to implement the Dudh-Kosi project.
The floor level of the 308 MW Lower Arun hydropower station will be 311 m, similarly the floor level of the Dudh-Kosi hydropower station will also be around 304 m. The maximum water level of the Kosi storage reservoir located further downstream based on Indian proposal would be 334 m. If the Kosi dam is designed according to the criteria applied to the Karnali dam, the maximum water level of the Kosi storage reservoir could reach to 390 m. Thus the hydropower stations of above mentioned two projects would be completely submerged into the Kosi storage reservoir.
The Tamar-1 is a storage project. This project must be designed and operated to fulfill the need for Kosi flood control side by side with power generation. It is explained hereinafter why it is necessary to implement in near future the Tamar-1 project and the Sun-Kosi project ahead of the Kosi dam project to resolve the Kosi flood problem. Unfortunately our Government has recently granted license to a private developer to conduct feasibility study to implement the Tamar-1 project exclusively for power generation.
The Dudh-Kosi project has been planned to discharge the Dudh-Kosi water after power generation directly into the Kosi reservoir bypassing the Sun-Kosi intake structures. As a result the power generation as well as irrigation coverage of the Sun-Kosi project would be significantly reduced.
Forerunners of Kosi Dam Project
There are four compelling reasons why the Sun-Kosi Dam Project along with comparatively very small Tamar-1 Storage Project , instead of Kosi dam project should be immediately implemented to prevent the Kosi flood disasters.
(1) Sun-Kosi Project and Tamar-1 Project can be quickly implemented within five to six years if it is decided to build them on war footing. These two projects can completely resolve the Kosi flood problems at least for a period of next 50 to 60 years.
(2) The mammoth Kosi Dam Project would be comparable in volume of works and complexity in engineering studies to China’s Three Gorges Project. It took China thirty years to complete the latter part of the studies and implementation of the Three Gorges Project. It would be immoral to let the people affected by Kosi flood to suffer for such a long period if there are other quick alternatives.
(3)Immediate implementation of the Kosi high dam would have devastating flooding in the lower reaches of the Kosi in Bihar due to extensive retrogression of the river bed immediately after the dam as was seen in Boulder Dam of the USA, Danjiangku ( a tributary of Yangtze) dam etc.
(4) It is not technically possible to implement the Sun-Kosi Dam Project if the Kosi Dam Project is implemented first but it is possible to implement the latter if the Sun_Kosi Dam Project is implemented earlier.
Sun_Kosi and Tamar-1 projects
Sun-Kosi project - Three alternative dam heights have been proposed for the Sun-Kosi project. They are 147m, 169m and 195m. Installed capacity could be 660 MW at 85% capacity factor. Annual firm energy output will be about 5,000 GWH. The total construction cost would be around US$ 1.5 billion.
Tamar-1 project - The height of the proposed Tamar-1 dam would be 153m. Initially the installed capacity could be reduced to 400 MW and in course of time it would be raised to 800 MW. The annual energy generation would be about 2,500 GWH. The total initial investment cost could be around US $ 1.0 billion
