KARNALI PROJECT COMPARABLE TO THREE GORGES PROJECT OF CHINA
By Dr. AB Thapa
The proposed Karnali Chisapani Project is one of the largest in the world. In many ways it is comparable to the China’s Three Gorges Project ( TGP ) which has been drawing since a long time the attention of the whole world because of the enormity of its size. The total storage volume of the Karnali Project reservoir is 39 billion cubic meters and similarly the total volume of the TGP is also about 39 billion cubic meters. After the full development the total installed capacity of the Karnali Project power station is expected to be about 16 million KW. The installed capacity of the TGP would be only slightly greater. It would be 18 million KW. Both these projects can provide enormously large irrigation, flood control and navigation benefits.
Karnali Project Potential ( Chisapani)
The Karnali Project (Chisapani) has the potential to provide irrigation benefits to India that could be as much as two times greater than the power benefit if it is presumed that the hydropower station capacity would be limited to only about 3000 MW to generate electricity primarily to meet the demand for base load and the dry season flow of the Karnali river would be completely used in Nepal whereas the irrigation in India would be entirely dependent on the regulated flow. If Nepal and India agree to follow the principle of sharing of downstream benefits as laid down in the Columbia River Treaty between the USA and Canada, Nepal could have virtually free of cost the Karnali Power Project ( scaled down). The economic potential of the Karnali Project would be lost forever if arrangements are not made with Indian Government to recover the irrigation and other downstream benefits well in advance before taking the decision to implement the project. A shortsighted decision would not only lead to the giving away of the Karnali water resources but it would also lead to losing the future market for irrigation in India adjacent to Western Nepal that would be saturated with freely available regulated Karnali water flowing into India from Nepal.
A Unified Strategy
The Karnali, West Seti and Pancheshwor projects are in the same Karnali basin. There is already a network of unified irrigation canal system in Indian territory to draw regulated flow from these projects. The electricity generated by future power stations belonging to these projects would also have to be supplied more or less to the same region. Nepal should, therefore, conduct an unified study of all these three projects taking into account the demand for power and irrigation in India to determine the best sequencing of these projects from our perspective.
Flood Control
A document published by the United States Department of Energy under the heading HYDROPOWER FACTS, 1998 indicates that out of the total dams built in the USA the primary benefit of 15% is flood control. The primary benefit of only 2% and 11% are hydropower and irrigation respectively. The Karnali storage reservoir will have enormously large flood storage capacity estimated to be about 11 billion cubic meters. There is a need to carry out the study to determine the downstream flood control benefits to be accrued from the storage of flood water. The Karnali feasibility report could not cover the flood control benefit study due to lack of data. A short excerpt from the Karnali project feasibility study on flood control is presented hereinafter.
"The Chisapani project has a substantial storage volume above the normal full supply level (FSL) for the purpose of storing and reducing incoming flood peaks. These will be discharged over the ungated spillway, which has a crest elevation at the normal FSL of 415 m. The resulting routing of floods will reduce the peak outflow of large flood peaks on the Karnali at Chisapani to about 20 - 25% of the peak flow. This will eliminate virtually all flood damages on the Karnali below the project site in Nepal, and flood damages will also be reduced further downstream in India, and even in Bangladesh. Benefits further downstream in India and in Bangladesh are very uncertain due to lack of data."
Inland Navigation
In the past the Karnali River was considered to be attractive for the development of navigation right from the Indo-Nepal border till the confluence of this river and the Ganges. The lower reach of this river was used in the past for navigation by steamers. The possibilities for further extension of the steamer services to the north had also been explored in the past. The Central Water and Power Commission of the Govt. of India had carried out hydrographical survey of the Karnali River from the Bahramghat to the confluence of this river and the Ganges a distance of 446 km. This survey was done in the years 1943-53 to explore the possibility of improvement and extension of navigation on this river by powered crafts. These surveys revealed that there were only 5 shoals under 90 cm at low water between Burhaj and Bahramghat a distance of about 300 km. The minimum depth was 75 cm. These depths were available without any river conservancy works. All other conditions of navigable channel such as the width and current of flow etc. were also found to be very favourable. The low water stage in this river is only for a short duration. There is a great urgency to carry out detailed study of the Karnali river to develop modern inland waterway by applying various channel improvement technologies. Needless to say that the consent of India is necessary to develop the Karnali waterway linking Nepal with the Ganges. Thus any difference in opinion should be settled with India before we take the decision to implement the Karnali Dam Project at Chisapani.
The Government of India has recently completed the construction of the Sarda-Sahayak scheme to use the water of the Mahakali as well as the Karnali River purely for the purpose of irrigation. Under this project a big canal has been provided that starts right from the Indo-Nepal border and ends at a point very close to the Ganges. This canal is 288 km long. This canal could be made navigable. It appears that this decision to build a canal solely for irrigation without a navigation component seemed to have been disapproved even by the Govt. of India experts looking after the inland navigation.
Mr. Verghese B.G. a well known Indian journalist writes "The Planning Commission's IWT consultants lament the fact that the parallel Ganges Canal now under construction in UP, like the long Sarada Sahayak Canal, is being constructed without a navigation component. Most often the sponsoring department - Irrigation in this case - is not concerned with navigation and is reluctant to think of larger dimensions while struggling to get approvals for its own project in the face of resource constraints. If planning were better integrated and had a longer perspective, some of these problems might be avoided".
In Europe there are innumerable cases when the existing small canals had be upgraded to raise the capacity to 1,350 ton standard. It could be of great interest to take up the study to convert the Sarda- Sahayak canal into irrigation cum navigation canal. .
In Conclusion
The Karnali Dam project at Chisapani has been a dream of the Nepalese people for last 50 years. Our government should not compromise national interest for the sake of a quick deal. The advice of Mr. Paul D. Terrell Jr. of Bechtel Company of the USA, who worked as Chief Advisor Consultant of the Karnali Project, is very close to the heart of every Nepali. Mr. Terrell had advised us " The present institutions should beware of giving away Nepali Children's rightful inheritance"
(Dr. Thapa writes on water resources)
