Indo-Nepal Relation And Water Resources

By DR. AB THAPA

Both India and Nepal could be enormously benefited if Nepal’s vast water resources are carefully developed based on sound engineering practices. Nepal could produce electricity in abundance to export to India . Similarly Nepal could expect to receive a fair share of the downstream benefits accruing to India from the use of regulated flows.. Needless to explain that the Indo-Nepal cooperation on water resources could have far reaching positive impact on economy of North India. Cheap electricity supplied from Nepal to industries in India could be a boon to enhance further their competitiveness in the domestic as well as world markets.

The Northern UP, of all other region of India, would be the main beneficiary. There are three major rivers that cross the Terai region of the western half of Nepal before entering into India. They are the Gandak, Karnali and Mahakali rivers. These three rivers carry on an average annual flow in the range of 3500 cumecs. Such enormous flow of these rivers could bring under year round irrigation a vast area of lands to the north of the Ganges river in the eastern UP. Nobody has any doubt that sooner or later the water drawn from the giant hydraulic structures built in Nepal would be transforming the vast tract of lands in India to the north of the Ganges river into one of the most advanced regions in agriculture production.

Local People Should Not Be Victimized

Local people should be assured that the proposed large water resource projects are not going to be implemented in a way detrimental to their genuine interest. Thus the problems such as the one related to Laxmanpur barrage ( called Rapti barrage in India) arising from the wrongly planned Saryu Canal should be quickly resolved to win the confidence of the local people living on both sides of the Rapti and other rivers in Nepalese territory. Their cooperation would be vital for the successful launching of the Karnali, West Seti and Pancheshwor storage projects.

If we carefully examined the West Rapti flood problem, it is not difficult to find out that the present flood problem is directly the result of the plans to build the Karnali or the West Seti or Pancheshwor storage dam projects. As a result, the governments of both India and Nepal could be blamed for the dreadful plight of people living in the eastern Banke district of Nepal. Thus both the governments should resolve the submersion problem at the earliest.

Indian Public Are Often Misled

In recent times almost every year widespread submersion and the loss of life and property are reported in the Indian territory due to the West Rapti floods . Unfortunately the poor people living in India who bear the brunt of the West Rapti flood disasters are often wrongly informed by certain section of the Indian press and even by some politicians. They try to lay the entire blame on Nepal for the West Rapti flood disasters They do not hesitate to convince the Indian public by falsely claiming, whenever there is a heavy spell of rainfall across the border in Indian territory which results in worsening of the West Rapti flood situation, that Nepal should be blamed for the flooding because it has opened the flood gates of its nonexistent West Rapti storage reservoirs.

Dr. K.L. Rao, a renowned expert in the field of water resources engineering and onetime Union Minister of Irrigation & Power, Government of India has very correctly explained the cause of the West Rapti flood problem. He has put forward his own ideas with a view to resolving the West Rapti flood problems in his book “India’s Water Wealth”.

Dr. K. L. Rao’s Observations

Flood plains are generally heavily populated since they are very fertile and are easily accessible. The Ganga basin has nearly 40% of India ’s population. The flood plains in India are not being developed in a regulated manner. Consequently, the damage and the loss of life and cattle due to floods are increasing year after year. The increase in damage due to the floods can also be attributed to the urbanization of the flood plains and the indiscriminate development of industries in areas normally liable to floods. As a result, whenever high magnitude floods occur, the damage is considerably more than in the days when the flood plains were mostly used for cultivation purposes.

Damage due to inundation can be reduced by limiting the flood discharges at the damage centre. Reservoirs, detention basins, diversions and soil conservation measures help in reducing the magnitude of the flood flows. Reservoirs and detention basins store a part of the flood waters and moderate the flood peaks. Diversions and floodways take a part of the flood flows to another basin, and consequently reduce the flood discharge in the main river. The floods affect the most densely populated areas of the country. They can be checked ( in case of the West Rapti river ) only by constructing detention reservoirs particularly on the Rapti at Sikta.

How the Submersion is Caused

The total length of the Saryu canal running almost parallel to Indo-Nepal border is about 230 km. In the original design the barrage across the Saryu river was at a location about 328 meters to the south of the railway bridge at Nanpara. Later, the design was modified and the location of the barrage was shifted 10 km to the north from the original site. The longitudinal gradient of the Saryu canal has been reduced to a minimum. It is only one meter on a stretch of 9 km. The adoption of such extremely mild slope permitted the alignment of the canal to be pushed as far as possible to the north very close to Indo-Nepal border specially in its middle and lower reaches.

Normally siphons are provided to deliver canal water across a river. A much higher average slope of the canal is required for the operation of this type of cross drainage structure, which has to operate under pressurized condition. A free flow hydraulic regime needs to be maintained at the river crossing if the average gradient of the canal is to be reduced. For reducing the average slope of the Saryu canal an altogether a different type of structures has been devised, which at first glance drives anybody crazy. Barrages have been built across the rivers to elevate the river water to such a level that would allow free passage of canal water across the river into the canal taking off from the other side of the river The contentious Laxmanpur barrage is one of such structures devised to deliver the water from the Girjapur barrage across the West Rapti river..

It would be necessary to maintain all the time pond water upstream of the barrage above certain fixed level to keep the Saryu canal running at desired capacity. Thus the pond would always be full, with the result that a sizeable area of lands in Nepalese territory could remain perpetually submerged. When the river is in flood, the water would be spreading out onto the lands that were never before regarded prone to flooding.

The Saryu canal is expected to cross innumerable small rivers and drains on its way. Embankments and dikes are needed to train these drains and small rivers for the protection of the Saryu canal. These river training structures could also result in widespread flooding inside Nepal where the canal route is close to the border

Similar Kosi Canal

India had proposed Nepal to build a canal similar to the Saryu canal to deliver Kosi water drawn near Chatra to irrigate lands as far as Birgunj in the west. Instead of such Indian proposal, Nepal indicated its decision to implement the Sun-Kosi diversion project. The Indian proposal was dropped. The following is the excerpt from the Indian proposal.

“The Project, therefore, envisages the construction of a new barrage at Chatra which would be 8 km downstream of the proposed Kosi High Dam, with two high level canals, one on each bank in Nepal. These canals are expected to serve one of the most fertile areas of the terrain in Nepal. Preliminary assessment on the basis of data available shows that it may be possible to cover a gross command of 11.05 lakh ha on the right bank and 4.17 lakh ha on the left bank ( both in Nepal and India). Another major advantage of providing Kosi waters to the high level canals in Nepal would be that, dependence on smaller rivers which are crossed by these canals would not be necessary and it may be possible to develop these rivers in an integrated manner along with Kosi water which would provide irrigation needs both in Nepal and India and at the same time release waters below Chatra for intensifying irrigation in India.”

(Thapa writes on water resources)