Apart from future economic survival even the physical existence of some regions of Nepal Terai would very much depend on adequate planning and implementation of water resources projects to be located deep inside hilly region far away from the Terai sacrificing to a considerable extent the environmental and economic interests of the hilly region. This type of project benefiting Terai has already started to be implemented. One of the perfect examples of this type of projects is the Bheri-Babai diversion project aimed at providing irrigation to Bardia and Banke districts, which is already under construction. There are several other such type of projects in advance planning stage to irrigate almost the entire Terai
Confusion Over New Consttitution
Unfortunately the vast majority of our Terai people are completely ignorant of the above facts. Even intelligentsia and politicians across the country do not yet seem to realize that it is inconceivable to think of sustainable future Terai detached from the adjoining high mountains and the Himalayan region, which are the perennial source of water supply to Terai in future. Failure of our policy makers to appreciate this reality and accordingly enlighten countrymen has thrown everybody into confusion and it might be the real cause of controversy in reaching a settlement acceptable to everyone in delineation of provincial boundaries. This issue will be bothering even after the promulgation of new constitution.
Nature of Water Resources Projects
Bheri- Babai project or similar other projects earmarked for implementation in future are completely extravagant worthless project from the view point of exclusively power generation. This type of projects necessitating construction of very long diversion tunnels are costly and on top of it involve substantial reduction in hydropower generation potential. Planning this type of projects precludes building a series of hydropower in cascade to tap the entire potential of the river. As a result, they can be justified only from the view point of Terai irrigation.
Abundant water diverted from the hill into Terai particularly in dry season is nothing less than nectar for parched Terai lands year by year suffering from constantly growing shortages of water critically needed to meet the irrigation requirement of Terai. These are the finding of vast studies already carried out by various reputed international agencies and donor governments.
Depletion of Water Resources in Terai
The water resources of Terai is being depleted due to the main following reasons:
(1) There was a rampant deforestation in the past across the entire Terai region and its adjoining Churia area. This has led to gradual drying up of the local rivulets and streams that were traditionally the source of local irrigation. Contrary to it, area under cultivation has greatly increased due to deforestation, which has led to increase in demand for water needed to irrigate new lands.
(2) There is rapid growth of population in the upper catchment areas of small and medium sized rivers also directly flowing into Terai from the hill areas. The flow of these rivers is being increasingly used in the hill region itself during the dry season since a long time with the result that the dry season flow of such rivers in Terai is constantly decreasing.
(3) Substantial withdrawal of ground water in future for irrigation in Bihar and UP that have deeper aquifer bottom would have adverse impact on ground water potential of our Terai. An example of such case is the Mississippi v. Memphis Ground Water Dispute in the USA. Mississippi state had blamed Tennessee for unlawfully withdrawing its ground water by forming deep cone of depression.
Terai Irrigation Projects
Detailed studies of several projects have already been conducted to recommend ways to resolve water supply to irrigate on a large scale Terai lands by diverting water from the water resources projects located far away in the mountain region. They are as follows:
Detailed irrigation development studies of all districts from Parsa to Saptari by diverting Sun-Kosi River were conducted with the help of UNDP/FAO; Similarly for Jhapa by diverting Kankai River(with the help of West German Govt. and ADB); For Rupandehi and Nawal Parasi by diverting Kali Gandaki river(with the help of UNDP); Kapilvastu by diverting West Rapti river (with the help of West German agency); Banke, Bardia, Kailali by ADB, JICA by diverting Bheri river along with irrigation water drawing directly from the Karnali storage dam project (with the help of ADB, JICA and World Bank). With the exception of irrigation in Jhapa and irrigation drawing water directly from the Karnali storage dam project, all other proposed schemes involve diversion of water from the mid hill by long tunneling across high mountains.
Kosi River Sorrow of Bihar
All rivers flowing from hills are liable to flooding in Terai resulting in some cases great losses. Kosi flood losses of all such cases acquire international significance because of the enormity of past and the imminent losses of life and property.
Kosi river known as the sorrow of Bihar had shifted from east to west over 70 miles within a period of 200 years. The shifting of the river course was accompanied by big loss of life and property in Nepal and India. However, the embankments built about 50 years ago have so far provided a great relief by preventing lateral shifting of the river course.
Kosi River Changing its Course
At present Kosi river channel bed is well above the surrounding grounds due to continued siltation. The embankments 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 extremely high flood discharge of almost nine lacks cusecs have already been measured twice within a short interval of 10 years some years ago when river bed siltation had just started. After that the flood discharge was mostly below 5 lacks cusecs.
Well known experts on Kosi, like Sir Claude Inglis, Shillingfeld and many others, have predicted that during the extremely high flood the Kosi would completely change its course breaching the eastern embankment right away near Chatra and would follow its original path about 70 miles to the east of the present course.
Devastation of Sunsari and Morang Districts
It is not difficult to predict based on Chinese experience of Yellow river flood control that the loss of life and property would be catastrophic if the Kosi river flowing at present on highly elevated bed spills across the embankment at the time of extremely high flood discharge. A substantial part of the Sunsari district including some part of Morang would be totally laid waste as the result of sediment deposition.
The flood affected areas would be completely devastated. The casualty would be very high. It is reported that the loss of life of people each time exceeded one million when the Yellow river embankments were breached during very high floods of 18 87 and 1931. It should be noted that the Yellow river according to Dr. K.L. Rao, former Minister of Govt. of India has almost a similar maximum discharge as the Kosi river.
Can Sunsari and Morang be Saved
According to opinions of renowned experts on Kosi, like Dr. A. N. Khosla, Dr. K. L. Rao and many others, and also based on Chinese experience we can say with absolute certainty that it would be necessary to implement Kosi or other big storage dam project to save the life and property of millions living in Sunsari and Morang
Hill People Unwilling
It is very likely that the hill people would be unwilling to accept above mentioned type of water resources projects benefiting Terai because they are going to be detrimental to their interest. It has already been explained that Nepal’s water resources development planning inclusive of tunneling to divert water to irrigate land in Terai will be more costly and at the same time the power generation potential will also be considerably reduced by comparison to alternative variant earmarked exclusively for power generation. Provision of large storage dam necessary for flood control in Terai will have devastating economic as well as environmental consequences for the people of mid hill. Just in one single Karnali Chisapani storage project case, the land area under submergence will exceed 40,000 hectares.
We know from the experience of India that there would be insurmountable opposition to this type of projects unless Terai and the adjoining northern mountain and Himalayan region are inseparably bound together within the same province.
Consequences of Inter States Rivalry
In our Indian Sub-continent dispute over water rights among the states of a country have greatly hampered development of water resources. India was easily able to resolve international water dispute over Indus and Ganges with Pakistan and Bangladesh respectively but conflicts among its states are not still fully resolved. The well known cases of such conflicts among Indian states are related to Godavari, Cauvery, Krishna and Narmada rivers.
In future people in mid-hill will have to pay very high price for implementing water resources projects to benefit the people of Terai. Thus, it is going to be very difficult to implement major water resources projects addressing the critical need of Terai if it is detached from the northern mountain and the Himalayan regions, which are the future source of water supply to parching lands of Terai.