In India, water resources are unevenly distributed. India has a vast geographical area of 329 mha. Interlinking of rivers is an attempt to link various rivers in the country to solve various problems such as flood control, irrigation problems, etc. Interlinking of rivers literally means joining of natural channels. Going by this natural geomorphologic process through which river systems and their flood plains are formed. This paper also deals with the “Case study of Bihar” in this aspect. Link channels are constructed to connect or transfer water of a river to another river belonging to a different basin. This paper deals with various aspects of interlinking of rivers.
Introduction of inter linking rivers :
The variations of the magnitude of annual rainfall in India are quite marked. It varies from an average of about 300cm in northeastern states of India to less than 15cm in its northwestern part in the semi arid and arid parts of Rajasthan and Gujarat. Also the Himalayan rivers flowing in the northern part of India are snow fed and perennial, the peninsular rivers are rain fed and seasonal. The hydrological, climatic and topographical factors cause recurrence of floods in certain parts of the country and some parts may be under scarcity of water.
The diversified distribution of dominant water demanding features such as density of population, irrigable land is the context that the interlinking of rivers for inter basin transfer of water on a national scale has been `haunting individuals and even engineers for more than a century. Linking of rivers and trans basin diversion of water is not new in our country and also other parts of the world. Diversion of river waters for cultivation of crops has been taking place from historical times. During recent times, the linking of rivers such as the Beas-sultlej link and the diversion of waters on a large scale to far off areas in rajasthan through the rajasthan canal is an excellent example. The 440 Km Narmada canal with a capacity of 40,000cusecs in the initial reach is also to supply water to some of the districts in Rajasthan. The diversion of 40,000 cusecs of Ganga waters at Farakka Barrage has also proved very useful. The present National plan for linking rivers has several components. The main ones are :
(i) Himalayan components and
(ii) Peninsular riverlinks system
The implementation of the Himalayan component depends on the co-operation of Nepal as the major tributaries of the Ganga originate in that country.
Need for Interlinking OF RIVERS
Somewhere people loose their lives, home, belongings due to floods or droughts. In either case people don’t have water to drink, a basic necessity for life.
Requirement of water: -
Irrigation-1,060 cubic meter
Domestic water supply and live stock – 90 billion Cu-m
Agriculture – 600 billion Cu-m
Industry – 64 billion Cu-m
Energy – 50 billion Cu-m
Total – 1,864 billion Cu-m
Thus the requirement of water will exceed the utilizable water resources of 1,122 billion Cu-m. The position of agriculture is no better. Today agriculture has become most unattractive job because of the floods and droughts. The Indian agriculture has been a “Gambling in monsoon”. The floods and droughts have remained permanent visitors causing havoc with Indian economy.
We witness frequent floods in some parts of the country causing havoc, devastation, damages, human suffering besides, a huge amount of public funds being spent on relief measures.
On the other hand, there is a large stretch of land vertically passing through the country as rain shadow area in the name of drought prone area, commencing from the Ramanathapuram in the south and ending up somewhere in the Ganganagar in Rajasthan traversing several districts in almost every state in south India. Many farmers died by making suicides in Karnataka due to lack of rainfall in the last five years.
Concept of interlinking of rivers
The concept of interlinking of rivers evolved during 1950s. At that time, the UN promoted such projects as part of “Stability and Peace”. That was the time when big projects and technology were seen as the answer to poverty. It was also the time when many countries, after gaining independence from colonial powers wanted to express their national confidence through such major projects. The interlinking of Indian rivers proposal originated at the same time as the world became fascinated with large water infrastructure projects.
Rivers, which join, act as drainage channels and entire river system so formed drains a specified area called the basin of that system. Thus intra-basin interlinking of rivers is a natural geomorphologic process. As distinct from this, interlinking of rivers belonging to altogether different basins is not a natural process and can only take place through man made devices. Essentially inter-basin transfer of water has been done through surface irrigation projects, in which lower portion of command areas include areas in the adjoining river basin through which water is conveyed through ridge canals. Such inter-basin transfer however, is marked by the following characteristics,
From the above points, it is clear that interlinking of rivers through inter-basin transfer of water is different from intra-basin linking of rivers. Interlinking of rivers that is being talked about as a national programme will have the following characteristics:
STUDY OF BIHAR Rivers
Bihar, a state situated in the eastern part of India, will serve and apt case to illustrate various issues and aspects related to interlinking of rivers. In the envisaged national scheme of interlinking of rivers, Bihar occurs significantly, probably as a water surplus region.
The present day Bihar, after a separate state of Jharkand, can be considered as comprising two distinct hydrological regions, North Bihar lying north of the river Ganga up to its border with Nepal and South Bihar lying south of Ganga adjoining Jharkand. While most of Bihar is part of the Ganga basin, north Bihar is drained by rivers originating in the Himalayas and Nepal, and south Bihar is drained by rivers originating in the Vindhyan, Chhotanagpur and Rajmahal hills. All these rivers join Ganga at various confluence points lying mostly in Bihar.
The fact that rivers of north Bihar cause recurrent floods, ie; they carry more water than they can contain within their banks and hence it is concluded that if this excess flow is transferred to a water deficit river/basin, it will not only provide valuable water to serve its needs but would also solve the problem of floods in north Bihar. For this, each component of the view is dealt with separately as follows.
RECURRENCE OF FLOODS AS CONCLUSIVE EVIDENCE OF SURPLUS
In the case of north Bihar, recurrent sccurences of floods are caused by a combination of the following five factors,
Hydrometeorological
The catchment areas of north Bihar rivers receive almost 85% of their annual precipitation during 4 months of the south-west monsoons during June-September, mostly concentrated during July and August. The annual precipitation varies from 130 cm in the North Bihar plains up to 300 cm on the southward slopes of the Himalayan part of the catchments in Nepal.
Hydrological
On an average, more than 60% (85% in the case of Kosi and 76% in the case of Gandak) of the aggregate catchments areas of north Bihar Rivers lie in high precipitation region outside north Bihar, mostly in Nepal.
Topographical
Catchments of north Bihar rivers undergo a very large and sharp change in gradients from very steep in the mountainous (Mt. Everest lies in these catchments) to steep in the sub-mountainous parts to extremely mild in the north Bihar plains through a relatively short stretch of 300 Km.
Hydraulic
When high flows resulting from run-off transformation of seasonally concentrated precipitation in higher precipitation upper catchments areas travel from steep gradients and encounter mild gradients downstream, they exceed the conveyance capacities of rivers in their lower reaches. So they spill over the banks and inundate the flood plains, using them as temporary dynamic storage.
Demographic
as the inundated flood plains support habitation, agriculture and other activities of a high-density population, floods cause recurrent disruption, damages and devastations on a large, attractin national attention. Recurrent floods in north Bihar constitute a case of ill management of water resources rather than being an indication of water being in surplus on an annual and basin wide scale. This is also linked by other facts and situations as mentioned below,
It is common experience that crops damaged by floods at one time suffer from agricultural drought subsequently. In Bihar, it is estimated that agricultural droughts cause 25% less in crop yields.
About 30% of cultivable land in north Bihar is presently under irrigation, while 90% of the cultivable land is irrigable. When this high potential irrigation is provided, agricultural water demand will rise considerably.
As per the “Report of second Bihar state irrigation” commission(1994) , irrigation water demands will fall short of availability of water in the state to meet food grain requirements of the rising population by the year 2025.
When India and Nepal will agree to co-operate in developing their shared water resources comprehensively, not only will north Bihar rivers be free from recurring floods, but other beneficial uses of water- consumptive as well as non-consumptive such as for irrigation, hydro-power generation, water transport, industrial as well as municipal uses and aquaculture will also be secured for immense mutual benefits. In that case, the perception of north Bihar rivers being water surplus will undergo a fundamental and conceptual change.
ENVIRONMENTAL, ECOLOGICAL AND HUMAN IMPACT
As interlinking of rivers is achieved by a combination of engineering measures such as dams, barrages, cross drainage structures and link channels, environmental and ecological impacts as well as displacement of people resulting form each of them will be the consequences of interlinking.
The link channels of interlinking system will be different from natural or other man made channels in the following ways along with their associated consequences. The purpose of a link channel is conveyance and transfer of water, as distinct from a natural channel, which is for drainage or irrigation channel which is for distribution of water or a navigation channel where basically depths are maintained for plying of boats. Link channels will mostly be in filling to avoid excessive lift, will have to cross natural drainage channels and may pass through forested or inhabited areas. These channels will generally carry high discharges requiring large cross sections, and hence these factors will lead to the following consequences.
Unless the link channels are lined, which will be a cost-prohibitive proposition, will cause heavy seepage which will not only constitute loss of water under transfer but may also create water logging conditions in certain areas.
They are likely to cause substantial displacement of people giving rise to problems of resettlement and rehabilitation. As the people to be displaced will be far from being beneficiaries, there is bound to be resistance on their part.
As these long link channels may pass through dense forest and habitats of wildlife, their ecological consequences may be serious and substantive.
Import of vast amount of water in arid or semi-arid areas may adversely affect their dry land ecology.
EXISTING INTER BASIN TRANSFER PROJECTS
The periyar Project, Parambikulam Aliyar Projet, Kurnool-Cudappah Canal and the Telugu Ganga Project in the south and inter sub-basin transfers in the Indus basin and Rajasthan canal project in the north are good examples of inter basin water transfers executed in India in 19th and 20th centuries.
The Periyar project
A masonry gravity dam 47.28m high has been constructed across a gorge on west flowing Periyar river. A1,740m long tunnel with a discharging capacity of 40.75m3/s has been driven across the mountain barrier to convey the waters eastwards to Vaigai basin. The project was commissioned in 1895 and provided irrigation to 57,923ha initially, which has since been extended to 81,069ha. There is also a power station of 140 MW capacity.
Rajasthan canal project
The project diverts water from the Himalayas to the deserts of Rajasthan. The project comprises of a huge multipurpose project constructed across the Beas river at Pong, a barrage at Harike and a grand canal system.
Introduction of inter linking rivers :
The variations of the magnitude of annual rainfall in India are quite marked. It varies from an average of about 300cm in northeastern states of India to less than 15cm in its northwestern part in the semi arid and arid parts of Rajasthan and Gujarat. Also the Himalayan rivers flowing in the northern part of India are snow fed and perennial, the peninsular rivers are rain fed and seasonal. The hydrological, climatic and topographical factors cause recurrence of floods in certain parts of the country and some parts may be under scarcity of water.
The diversified distribution of dominant water demanding features such as density of population, irrigable land is the context that the interlinking of rivers for inter basin transfer of water on a national scale has been `haunting individuals and even engineers for more than a century. Linking of rivers and trans basin diversion of water is not new in our country and also other parts of the world. Diversion of river waters for cultivation of crops has been taking place from historical times. During recent times, the linking of rivers such as the Beas-sultlej link and the diversion of waters on a large scale to far off areas in rajasthan through the rajasthan canal is an excellent example. The 440 Km Narmada canal with a capacity of 40,000cusecs in the initial reach is also to supply water to some of the districts in Rajasthan. The diversion of 40,000 cusecs of Ganga waters at Farakka Barrage has also proved very useful. The present National plan for linking rivers has several components. The main ones are :
(i) Himalayan components and
(ii) Peninsular riverlinks system
The implementation of the Himalayan component depends on the co-operation of Nepal as the major tributaries of the Ganga originate in that country.
Need for Interlinking OF RIVERS
Somewhere people loose their lives, home, belongings due to floods or droughts. In either case people don’t have water to drink, a basic necessity for life.
Requirement of water: -
Irrigation-1,060 cubic meter
Domestic water supply and live stock – 90 billion Cu-m
Agriculture – 600 billion Cu-m
Industry – 64 billion Cu-m
Energy – 50 billion Cu-m
Total – 1,864 billion Cu-m
Thus the requirement of water will exceed the utilizable water resources of 1,122 billion Cu-m. The position of agriculture is no better. Today agriculture has become most unattractive job because of the floods and droughts. The Indian agriculture has been a “Gambling in monsoon”. The floods and droughts have remained permanent visitors causing havoc with Indian economy.
We witness frequent floods in some parts of the country causing havoc, devastation, damages, human suffering besides, a huge amount of public funds being spent on relief measures.
On the other hand, there is a large stretch of land vertically passing through the country as rain shadow area in the name of drought prone area, commencing from the Ramanathapuram in the south and ending up somewhere in the Ganganagar in Rajasthan traversing several districts in almost every state in south India. Many farmers died by making suicides in Karnataka due to lack of rainfall in the last five years.
Concept of interlinking of rivers
The concept of interlinking of rivers evolved during 1950s. At that time, the UN promoted such projects as part of “Stability and Peace”. That was the time when big projects and technology were seen as the answer to poverty. It was also the time when many countries, after gaining independence from colonial powers wanted to express their national confidence through such major projects. The interlinking of Indian rivers proposal originated at the same time as the world became fascinated with large water infrastructure projects.
Rivers, which join, act as drainage channels and entire river system so formed drains a specified area called the basin of that system. Thus intra-basin interlinking of rivers is a natural geomorphologic process. As distinct from this, interlinking of rivers belonging to altogether different basins is not a natural process and can only take place through man made devices. Essentially inter-basin transfer of water has been done through surface irrigation projects, in which lower portion of command areas include areas in the adjoining river basin through which water is conveyed through ridge canals. Such inter-basin transfer however, is marked by the following characteristics,
From the above points, it is clear that interlinking of rivers through inter-basin transfer of water is different from intra-basin linking of rivers. Interlinking of rivers that is being talked about as a national programme will have the following characteristics:
STUDY OF BIHAR Rivers
Bihar, a state situated in the eastern part of India, will serve and apt case to illustrate various issues and aspects related to interlinking of rivers. In the envisaged national scheme of interlinking of rivers, Bihar occurs significantly, probably as a water surplus region.
The present day Bihar, after a separate state of Jharkand, can be considered as comprising two distinct hydrological regions, North Bihar lying north of the river Ganga up to its border with Nepal and South Bihar lying south of Ganga adjoining Jharkand. While most of Bihar is part of the Ganga basin, north Bihar is drained by rivers originating in the Himalayas and Nepal, and south Bihar is drained by rivers originating in the Vindhyan, Chhotanagpur and Rajmahal hills. All these rivers join Ganga at various confluence points lying mostly in Bihar.
The fact that rivers of north Bihar cause recurrent floods, ie; they carry more water than they can contain within their banks and hence it is concluded that if this excess flow is transferred to a water deficit river/basin, it will not only provide valuable water to serve its needs but would also solve the problem of floods in north Bihar. For this, each component of the view is dealt with separately as follows.
RECURRENCE OF FLOODS AS CONCLUSIVE EVIDENCE OF SURPLUS
In the case of north Bihar, recurrent sccurences of floods are caused by a combination of the following five factors,
Hydrometeorological
The catchment areas of north Bihar rivers receive almost 85% of their annual precipitation during 4 months of the south-west monsoons during June-September, mostly concentrated during July and August. The annual precipitation varies from 130 cm in the North Bihar plains up to 300 cm on the southward slopes of the Himalayan part of the catchments in Nepal.
Hydrological
On an average, more than 60% (85% in the case of Kosi and 76% in the case of Gandak) of the aggregate catchments areas of north Bihar Rivers lie in high precipitation region outside north Bihar, mostly in Nepal.
Topographical
Catchments of north Bihar rivers undergo a very large and sharp change in gradients from very steep in the mountainous (Mt. Everest lies in these catchments) to steep in the sub-mountainous parts to extremely mild in the north Bihar plains through a relatively short stretch of 300 Km.
Hydraulic
When high flows resulting from run-off transformation of seasonally concentrated precipitation in higher precipitation upper catchments areas travel from steep gradients and encounter mild gradients downstream, they exceed the conveyance capacities of rivers in their lower reaches. So they spill over the banks and inundate the flood plains, using them as temporary dynamic storage.
Demographic
as the inundated flood plains support habitation, agriculture and other activities of a high-density population, floods cause recurrent disruption, damages and devastations on a large, attractin national attention. Recurrent floods in north Bihar constitute a case of ill management of water resources rather than being an indication of water being in surplus on an annual and basin wide scale. This is also linked by other facts and situations as mentioned below,
It is common experience that crops damaged by floods at one time suffer from agricultural drought subsequently. In Bihar, it is estimated that agricultural droughts cause 25% less in crop yields.
About 30% of cultivable land in north Bihar is presently under irrigation, while 90% of the cultivable land is irrigable. When this high potential irrigation is provided, agricultural water demand will rise considerably.
As per the “Report of second Bihar state irrigation” commission(1994) , irrigation water demands will fall short of availability of water in the state to meet food grain requirements of the rising population by the year 2025.
When India and Nepal will agree to co-operate in developing their shared water resources comprehensively, not only will north Bihar rivers be free from recurring floods, but other beneficial uses of water- consumptive as well as non-consumptive such as for irrigation, hydro-power generation, water transport, industrial as well as municipal uses and aquaculture will also be secured for immense mutual benefits. In that case, the perception of north Bihar rivers being water surplus will undergo a fundamental and conceptual change.
ENVIRONMENTAL, ECOLOGICAL AND HUMAN IMPACT
As interlinking of rivers is achieved by a combination of engineering measures such as dams, barrages, cross drainage structures and link channels, environmental and ecological impacts as well as displacement of people resulting form each of them will be the consequences of interlinking.
The link channels of interlinking system will be different from natural or other man made channels in the following ways along with their associated consequences. The purpose of a link channel is conveyance and transfer of water, as distinct from a natural channel, which is for drainage or irrigation channel which is for distribution of water or a navigation channel where basically depths are maintained for plying of boats. Link channels will mostly be in filling to avoid excessive lift, will have to cross natural drainage channels and may pass through forested or inhabited areas. These channels will generally carry high discharges requiring large cross sections, and hence these factors will lead to the following consequences.
Unless the link channels are lined, which will be a cost-prohibitive proposition, will cause heavy seepage which will not only constitute loss of water under transfer but may also create water logging conditions in certain areas.
They are likely to cause substantial displacement of people giving rise to problems of resettlement and rehabilitation. As the people to be displaced will be far from being beneficiaries, there is bound to be resistance on their part.
As these long link channels may pass through dense forest and habitats of wildlife, their ecological consequences may be serious and substantive.
Import of vast amount of water in arid or semi-arid areas may adversely affect their dry land ecology.
EXISTING INTER BASIN TRANSFER PROJECTS
The periyar Project, Parambikulam Aliyar Projet, Kurnool-Cudappah Canal and the Telugu Ganga Project in the south and inter sub-basin transfers in the Indus basin and Rajasthan canal project in the north are good examples of inter basin water transfers executed in India in 19th and 20th centuries.
The Periyar project
A masonry gravity dam 47.28m high has been constructed across a gorge on west flowing Periyar river. A1,740m long tunnel with a discharging capacity of 40.75m3/s has been driven across the mountain barrier to convey the waters eastwards to Vaigai basin. The project was commissioned in 1895 and provided irrigation to 57,923ha initially, which has since been extended to 81,069ha. There is also a power station of 140 MW capacity.
Rajasthan canal project
The project diverts water from the Himalayas to the deserts of Rajasthan. The project comprises of a huge multipurpose project constructed across the Beas river at Pong, a barrage at Harike and a grand canal system.
IN ABROAD
In United States, the California’s state water project, first phase of which was completed in 1973, provides for the diversion of 4 cubic Km of flow from better watered northern California to the drier central and southern parts of the state. The conveyance system comprises of 715 Km long California aquaducts a complec system of lined and unlined canals, pumping stations, siphons and tunnels. The lift involved is nearly 1,000m.
Inter basin transfer projects have also been planned and implemented in China and former USSR. A notable scheme executed in the USSR is Irtysh Karaganda scheme in the central Kazakistan. The link canal is about 450 Km long with a maximum capacity of 75 cumecs. Lift involved is 14 to 22 m. other proposals include partial redistribution of water resources of northern rivers and lakes of European part to the Caspian sea basin involving 2 M.ha-m of water.In china recently completed inter basin transfer include Biliuha-Daliah inter basin water supply system, trans basin transfer of Luhana river to Tiajian river and Tengshan. Diversion of yellow river surpluses and south to north transfer project.
In United States, the California’s state water project, first phase of which was completed in 1973, provides for the diversion of 4 cubic Km of flow from better watered northern California to the drier central and southern parts of the state. The conveyance system comprises of 715 Km long California aquaducts a complec system of lined and unlined canals, pumping stations, siphons and tunnels. The lift involved is nearly 1,000m.
Inter basin transfer projects have also been planned and implemented in China and former USSR. A notable scheme executed in the USSR is Irtysh Karaganda scheme in the central Kazakistan. The link canal is about 450 Km long with a maximum capacity of 75 cumecs. Lift involved is 14 to 22 m. other proposals include partial redistribution of water resources of northern rivers and lakes of European part to the Caspian sea basin involving 2 M.ha-m of water.In china recently completed inter basin transfer include Biliuha-Daliah inter basin water supply system, trans basin transfer of Luhana river to Tiajian river and Tengshan. Diversion of yellow river surpluses and south to north transfer project.
Save the sweet water sources and don't waste the drinking water. If we are spoiling the drinking water continously, time will be turn and one day we will purchase the drinking water as like now purchasing the petrol. Think it and proceed it it is very important.
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