In course of first official visit of our then Prime-minister G.P. Koirala to India an agreement was signed to conduct jointly detailed feasibility study of the Kosi High Dam Project. This type of isolated study of the Kosi dam project could be detrimental to the interest of our country since Sun-kosi and Kosi navigation projects are extremely important projects directly tied up with the Kosi Dam Project. I raised this issue within the Ministry of Water Resources displeasing many of my colleagues, who regarded that an agreement already signed between two prime-ministers should not be questioned. But I did not give in.
I prepared based on my own personal experience a new plan for the Kosi river development that could be put to the Indo-Nepal joint meeting. The proposed plan has been presented in two reports ( Ref-1, Ref-2). Those reports had been circulated to various concerned agencies. Similarly important findings of those reports have been published in several local newspapers and magazines. The conclusions of the reports can be roughly presented under four headings.
At present Kosi river channel bed is well above the surrounding grounds due to continued siltation. The embankment have already outlived their useful life. We have already witnessed enormous loss of life and property in 2008 breach of Kosi embankment when the flood discharge was only about 1 ½ lack cusecs, where-as flood discharge of almost nine lacks cusecs have already been measured twice within the last fifty years. Thus flood control would be the most important benefit to accrue from large storage projects to be built in the Kosi basin. However, until the !997 Indo- Nepal joint meeting Indian Government had been maintaining the view communicated to our government through official correspondence that Kosi flood problems have already been solved forever after the completion of the construction of the Kosi embankments. It is absolutely necessary to implement large storage dam projects within the Kosi basin to save the life and property of millions living particularly in North Bihar and also in some parts of the Sunsari district of Nepal.
Sun-Kosi High Dam First
Simple Sun-Kosi diversion project ( without high dam) and the proposed Kosi dam project are mutually exclusive of one another. Similarly, the Sun-Kosi high dam project and the Kosi high dam project would also be mutually exclusive of one another if the Kosi dam is built first. Thus the Sun-Kosi dam project would have to be implemented FIRST.
Optimum height of the Kosi dam would be over 335 m. It would be the highest dam in the world. India has proposed a dam height of 269 m. In either case the site of the Sun-Kosi dam would be submerged if the Kosi dam is built first. Thus the detailed study of the Sun-Kosi project should also be immediately started to complete the construction of the Sun-Kosi dam project before starting the construction of the Kosi dam.
Sun-Kosi Dam Site
The site of the Sun-Kosi storage dam to be built for diverting this river onto Terai plain had been identified based on several past studies. It is located just downstream of the confluence of the Sun-Kosi and Dudh-Kosi rivers. The place is called KURULE.
Kosi Canal Navigation
The concept of Kosi navigation canal linking Nepal with the seaport is entirely mine. Nepal as well as Bihar could greatly benefit from the proposed navigation canal.
Conclusion of 1997 Indo-Nepal Joint Meeting
As head of Nepal team I was easily able to convince the Indian delegates our view points on Kosi development. The Indo-Nepal joint meeting completely endorsed our proposal as described in my two reports. However, nobody was expecting that Indo-Nepal joint meeting could so easily reach an agreement about the thorny Kosi river issue. People had good reason to suspect that Nepal’s interest might have been compromised. Some political parties even denounced the agreement. Kosi agreement was front-page news. Some papers even blamed me that I had wrongly signed the Kosi study agreement.
Gradually people started to realize that the Kosi study agreement was in conformity to our country’s long term development plan. I was helped by MITRAKUNJ to organize a meeting in Russian Cultural Centre attended by relevant experts, politicians, media persons distinguished in the field of water resources. I explained in the meeting the Kosi problems. Those attending the meeting realized the significance of the Kosi study agreement. The following day all papers covered positively Kosi news.
Shocking New Developments
It is quite shocking that our own government is now trying to reduce significantly the flow of the Sun-Kosi river presently available at Kurule site for irrigation in Terai by diverting the Dudh-Kosi river further downstream away from the Sun-Kosi diversion intake. In such case our Terai people would be experiencing shortage of water supply for irrigation even after the completion of the Sun-Kosi project particularly in later years because the limited storage volume of the Sun-Kosi reservoir could be expected to be filled up relatively quickly.
It is also rumoured that our government is going to abandon the Kurule site in order to build the diversion dam further upstream at a new site perhaps out of the reach of Kosi reservoir submergence area even though such change would result to significant reduction of dry season flow available for irrigation in Terai. The sole purpose of such change would be to limit the availability of Sun-Kosi water in our Terai and also to pave the way to implement first the Kosi High Dam Project that would indefinitely delay the construction of the Sun-Kosi project.
REFERENCE - (1) Planning Kosi High Dam Project, Thapa AB 1993; (2) Kosi Canal Waterway, Thapa AB 1993