An Analysis of the National River Linking Project of India

AN ANALYSIS OF THE NATIONAL RIVER LINKING PROJECT

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ABSTRACT

Coping with annual floods and droughts, both occurring at the same time in different parts, has been a major concern for India over the years. These concerns are more acute today as the growing population and the resultant increase in water demand place a heavy burden on the unevenly distributed water resources, and also cause huge economic losses to the financially vulnerable groups of the population. Additionally, there is a huge demand to enhance and diversify food production

Designed to address these issues, the National River Linking Project proposes to transfer water from the potentially water surplus Himalayan rivers to the water-scarce river basins of western and peninsular India. The NRLP will build 30 river links and approximately 3000 storages to connect 37 Himalayan and peninsular rivers to form a gigantic south Asian water grid. Environmentalists questioned the ecological cost of large dams, while the NGOs and civil society probed the social cost of people displacement. However, much of the arguments for and against the project have little analytical rigor. This analysis has been done to provide a balanced analysis of the pros and cons of the NRLP components


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TABLE OF CONTENTS

CHAPTER

TITLE

PAGE

ABSTRACT LIST OF FIGURES 1 INTROUCTION 1.1 GENERAL 1.2 NEED FOR THE PROJECT 1.3METHODS OF INTERLINKING 2 THE CONDITION OF WATER IN INDIA 2.1 DISTRIBUTION OF WATER 2.2 SUPPLIES AND CONSUMPTION OF WATER 2.3 WATER SCENARIO IN THE FUTURE 3 AN OVER VIEW OF THE NRLP 3.1 PROPOSED RIVER LINKS 3.3 BUDGET AND COST ESTIMATES 3.4 CHALLENGES FACING THE PROJECT 3.5 RISK ASSESMENT 4 CASE STUDY: POLLAVARAM PROJECT 4.1 GODAVARI-KRISHNA TRANSFERS 4.2 POLAVARAM PROJECT DESCRIPTION 4.3 METHODS 4.4 Results and discussions 4.5 CONCLUSION

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LIST OF FIGURES

FIGURE1: Distribution of average annual water resources for 1974 and 2025 (Pg. 10) FIGURE3: Links envisaged as per the National Perspective Plan(Pg.15) FIGURE4: Map of Krishna and Godavari basins(Pg. 23)


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LIST OFABREVIATIONS

N.W.P National Water Policy N.W.D.A National Water Development Agency W.E.A.P Water Evaluation and Planning Model S.E.I Stockholm Environment Institute D.E.M Digital Elevation Model E.F Environment Flow N.R.L.P National River Linking Plan


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CHAPTER 1

INTRODUCTION 1.1 GENERALThe world is fast running out of usable water. Anthropogenic activities are polluting and depleting this finite wellspring of life at a startling rate. Industrialization, intensive agriculture, pollution, deforestation, and construction of large dams have damaged the earths surface water in persistent ways. Quite simply, unless we change our ways and practices the world will be living with freshwater shortages in the coming future.

Keeping in view the increasing demand for water, the government of India developed a new National Water Policy, which states that water is a prime natural resource, a basic need and a precious national asset. Planning, development, and management of water resources need to be governed by national perspectives (National Water Policy 2002).

While there exists excellent literature on different alternatives to water management since independence, the national perspective guiding water resource development in India has focused on a supply-based paradigm as the only alternative to meet water needs for such diverse purposes as irrigation, drinking water, sanitation, industrial and other uses in a sustainable manner. This top-down solution to Indias growing water needs has stirred controversy and debate in one of the worlds largest democracies. This paper addresses the challenges inherent in the governments policy decision to interlink rivers as envisaged by the bureaucratic agency of state power.


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1.2 NEED FOR THE PROJECT y Flood controly Cheap water for irrigation y Drinking water y Hydroelectric power y Employment generation y Inland navigation y National integration


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CHAPTER 2 THE CONDITION OF WATER IN INDIA

2.1 DISTRIBUTION OF WATERDespite opulent precipitation of 4,000 cubic km annually over India, 3,000 cubic km of the total is confined to the four months of monsoon, with the remaining 1,000 cubic km falling in the remaining eight months of the year. Even this precipitation is uneven. Parts of the country have abundant precipitation and others face extreme water deficits. The bulk of water during the monsoon washes into the oceans unused. Annual water resources of the country are measured in terms of runoff in the river systems, estimated by the National Commission as 1,953 cubic km. However, the utilizable resources of the country are 690 cubic km of surface water and 396 cubic km of ground water (Ministry of Water Resources 1999a).

2.2 SUPPLIES AND CONSUMPTION OF WATERProfligate consumption of the limited supply of water is the most pervasive and persistent problem to contain, accompanied by anomalies of mismanagement and the failure of the population to embrace conservation of this vital resource. The problem of storage is exacerbated by a faulty distribution system, differences in consumption, leakage and evaporation, and consumer wastage. The present ineffective management of water ignores the potential of conservation and embraces the alternative of increasing supply. Degraded watersheds, drying local pond systems, shrinking canal networks, and wetland degradation as a result of anthropogenic activity and climate change relegate water to the status of scarce commodity. The ever-increasing stress caused by population growth and concomitant increased agricultural and industrial demands for water have created an apparent scenario ofAN ANALYSIS OF THE NATIONAL RIVER LINKING PROJECT

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water shortage that requires augmentation. Figure 1 below describes the distribution of water resources for the years 1974 (actual) and 2025 (projected).


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2.3 WATER SCENARIO IN THE FUTUREThe simulations of utilizable water scenarios up to 2050 as calculated by the Ministry of Water Resources provide a snap shot of the existing and future scenarios. The utilizable surface water and ground water remains 690 km3 and 396 km3 under both low and high demand scenarios. However, total water requirement and return flow are steadily rising in future in terms of the national average, basin studies, and state studies. Return flow follows similar trends. The data shows a corresponding decline in residual utilizable water

In these scenarios, where supply will barely meet demand, the National Commission noted that the situation will not become a crisis if steps are taken in advance. Water availability needs to be enhanced from the present 520 BCM, but population growth has to be contained to the low demand scenario of 2050 to match requirements, along with optimal development of utilizable water resources in the country. If water requirements reach those projected under a high demand scenario, the estimated resource availability will simply not be able to match the demand of 1,180 BCM.

In addition to the spatial availability of water, the impending crisis in water is also due to inadequate water management and environmental degradation, rampant pollution, lack of efficiency in water use, and inadequate attention to conservation. Admittedly, water scarcity to some extent is a social construct, in spite of seasonal and temporal variations of water availability as reflected in the basic compilation of water demands and yields.


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CHAPTER 3 AN OVER VIEW OF THE NRLP

3.1 PROPOSED RIVER LINKS 3.1.1 HIMALAYAN COMPONENTThe interlinking river project is separated into two primary components. The Himalayan Component proposes fourteen canals (Table 3) and the Peninsular Component sixteen (Table 4, opposite). In the Himalayan Component, many dams are slated for construction on tributaries of the Ganga and Brahmaputra in India, Nepal, and Bhutan. The project intends to link the Brahmaputra and its tributaries with the Ganga and the Ganga with the Mahanadi River to transfer surplus water from east to west. The scheme envisages flood control in the Ganga and Brahmaputra basins and a reduction in water deficits for many states.


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3.1.2 PENINSULAR COMPONENTIn the Peninsular Component, river interlinks are envisaged to benefit the states of Orissa, Karnataka, Tamil Nadu, Gujarat, Pondicherry, and Maharashtra. The linkage of the Mahanadi and Godavari rivers is proposed to feed the Krishna, Pennar, Cauvery, and Vaigai rivers. Transfer of water from Godavari and Krishna entails pumping 1,200 cusecs of water over a crest of about 116 meters. Interlinking the Ken with the Betwa, Parbati, Kalisindh, and Chambal rivers is proposed to benefit Madhya Pradesh and Rajasthan.

The project is likely to alter the geography of the country, impose ecological risks, and also inadvertently distribute pollutant loads across the rivers, spreading local contamination problems and raising questions of accountability for sources of pollution. Recurrent droughts and incessant water shortages are looked upon as an opportunity to put aside these forgotten problems. While the reasons for drying up of the Sabarmati remain unaccounted for, diverting the waters of Narmada 225 km upstream has restored its flow. The Sabarmati recorded an average annual flow of 3,200 cubic meters, instead of creating conditions for recharge in the 21,674 sq km of its watershed. The assumption op. cit. is based on good rains in Madhya Pradesh providing enough water to Narmada for sharing it with Sabarmati. The Sabarmati today has been reduced to a canal dependent on Narmada.


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3.3 BUDGET AND COST ESTIMATESThe estimated cost (in 2002) of interlinking rivers stands at Rs. 5,60,000 crores (Goyal 2003)equivalent to approximately $122.7 billionwith an annual outlay over thirty-five years of Rs. 16,000 crores ($3.5 billion). Another estimate puts it close to 5,56,000 crores ($121.8 billion), out of which Rs. 3,30,000 crores ($72.3 billion) is earmarked for linking the Himalayan rivers with the various peninsular rivers (Sharma 2003). The Central Government is estimated to need Rs. 20,000 crores ($4.4 billion) a year to execute the project (Goyal 2003). Gujja (2003) estimates Rs. 5,50,000 crores ($120.5 billion) as the cost of completing what would be the largest civil engineering project ever in India. As a long term project, the actual inflation and potential cost increases during such a long span are anybodys guess. Long term planning and a sound financial simulation are required to meet the standard of due diligence for such proposals.

Yet, the government seems ready to commit this huge expenditure mostly because of popular sentiment. The economic viability of the project remains questionable. Technical feasibility studies have yet to be carried out. Raising Rs. 33,000 crores ($7.2 billion) each year over ten years is by no means a small task as this amount is twice that of current annual tax collections.

Proponents of the river linking project argue that water scarcity or surplus is a result of extreme conditions of flood or drought that are at the mercy of the vagaries of natural precipitation. To some extent, the scarcity of water could be overcome by harvesting water locally, but such a strategy cannot solve the national problem of uneven distribution of hydrologic resources. Local watershed developments are viable as stand alone projects, since effective conservation of water is possible only at local levels. In supporting the plan, the National Water Development Agency affirmsAN ANALYSIS OF THE NATIONAL RIVER LINKING PROJECT

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that it will provide water to irrigate 35 million hectares of farmland and supply 34 million kilowatts of hydroelectricity From the basic compilation of water demands and yields, a National Water Grid seems imperative and the interlinking of rivers necessary to foster equitable water transfers from surplus to scarce basins of India. In addition to transferring water from surplus to deficit areas, the scheme to interlink rivers also presumes that water will be stored and released at the optimal time and place, bringing its availability under human control. It is asserted that the scheme would provide protection from floods and droughts, while also promoting the availability of water for nature, agriculture, and industry (Jhunjhunwala 2002). In addition to construction of dams and barrages, it would promote generation of hydroelectricity, which is linked with industrial growth and quality of life measurements.

To its opponents, the river interlinking project has been looked upon as an a priori proposition that undermines conservation of a scarce resource; signals a return to centralized, bureaucratic projects prone to failure; is potentially fraught with serious environmental consequences; was announced in advance of standard review procedures of scientific evaluation, appraisal, and approval; and represents a distortion of priorities, pre- empting resources and attention from other social projects that are a higher priority. The National Commission on Integrated Water Resource Development Plan (Ministry of Water Resources 1999b) commented, there seems to be no imperative necessity for massive water transfers. The assessed needs of basins could be met from full development and efficient utilization of intra-basin resources except in the case of Cauvery and Vaigai basins. Therefore, it is felt that limited water transfers from Godavari at Khampalli and Polavarum towards South would take care of the deficit in Cauvery and Vaigai basins. The Commission noted that further studies of inter-basin transfers need to be undertaken to clarify the true costs, benefits, and drawbacks of such massive projects.


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Proposals to interlink the rivers of India also entail massive economic, ecological, and social costs. At the time K.L. Rao first proposed the project decades ago, these watersheds had more water, less pollution, lesser deforestation, and floods that were not so severe or frequent as now. Since then, the Indian population has increased enormously; efforts to aid those afflicted by the problems of displacement and rehabilitation that inevitably accompany such projects must be taken as a prerequisite. Increasingly, the entire socio-economic strata of affected people are more aware of their rights and know how to protest, agitate, and demand their due. Such changed circumstances are bound to create impediments to the execution of the project and offer stiff resistance to it. The involvement of global capital will have its own complications. In recent years, popular awareness, participation, and empowerment in evaluation of such projects has created an awareness of merits and demerits they offer, along with recognition of alternative solutions. These conditions present a number of challenges.

3.4 CHALLENGES FACING THE PROJECT3.4.1 TECHNOLOGICAL CHALLENGES

Basically, the interlinking project aims to transfer floodwaters of the Ganga and Brahmaputra river basins to the peninsular areas of South India. There are three options to accomplish such transfer of surplus water. First is the canal option to construct lengthy canals for the purpose; second, the tunnel option allows water to flow under mountains; and third is the pumping option that will transfer water over mountains by pumping. An analysis of the engineering options to deal with these challenges in trying to implement the project does not seem to be an easy task (Vombatkere 2003).


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3.4.1.1 CANALS: A canal running along topographical contours will allow water flow in a unidirectional manner. The donor states will accept this proposition only. Interstate transfer of water will be problematic and issues of inter- river transfer of water cannot be easily resolved. Canals will interfere with the natural flow of water and divert part of the flow alongside their embankments as they cut through intersecting watercourses. Canals will function as catch-basins, easily becoming filled with silt and residue that will reduce their capacity, requiring regular dredging. Trees and other vegetation will tend to grow profusely in this water-rich zone, necessitating regular bank clearance work to maintain structural integrity of the canal system.

3.4.1.2 PUMPING: Pumping water over the Vindhya Mountains can transfer the Ganga-Brahmaputra water and its tributaries to regions in the south. The Ganga-Brahmaputra floodplains are about ten meters above mean sea level (MSL). The Vindhya Mountains are about 300 m above MSL, separating the floodplains of the north from the Deccan Plateau, which is 250 m above MSL (Vombatkere 2003). The electric power required to pump water to such heights will be close to the current power generation of the entire nation.

3.4.1.3 TUNELLING: Tunneling tens of kilometers would involve a huge expenditure. The fiscal accounting of interlinking rivers makes this option uneconomical. Thus the technological options envisaged have both economic as well as socio-environmental consequences to deal with.


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3.4.2 ECONOMIC CHALLENGESSuch a mega project cannot be completed with national funds currently at the disposal of the government. The huge expenditure implicit in it will likely create fiscal problems that are difficult to manage, stressing the economy. The maintenance cost and physical position of the dams, canals, tunnels, and captive electric power generation created, as capital assets under the plan will involve huge financial burdens. This implies the need for the private sector, as well as global capital agencies, to be involved in the project. The Indian economy cannot finance such an enormous project on its own. To meet the estimated budget of Rs. 5,60,000 crores ($122.7 billion), financing dependent on private sources, the World Bank or the Asian Development Bank is likely to affect the economic and political independence of the nation. Such a process entails the challenge of having to abandon regulatory regimes and allow the market to make decisions over water resources under the influence of the World Bank. If implemented, such a plan should be self-sustaining so that, if the loan liabilities remain unpaid, the creditor banks do not use it to force entry into India and consolidate the control of foreign interests over the national economy.

3.5 RISK ASSESMENTThe water surplus during JulyOctober in the donor area of the Ganga-Brahmaputra basin is not available at the time needed (JanuaryMay) in the peninsular rivers recipient area. Utilizing surplus waters, therefore, will require enormous holding reservoirs; the direct transfer of surplus water is not possible. In spite of all conventional safety designs in building dams and reservoirs, the element of risk cannot be ignored where human interaction with large ecosystems is taking place on such a massive scale. M. Tully (2003) described the impacts on human activities as the most valid argument against the project. Reductions in flooding by diversion ofAN ANALYSIS OF THE NATIONAL RIVER LINKING PROJECT

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water will cause reductions in land fertility and promote desertification. Reduction in flows of rivers as a result of diversion of water will reduce purging of pollutant concentrations in certain river stretches and intensify water pollution there. Such transformations will also impose ecological risks of a nature that are bound to have unprecedented effects. To secure the National Water Grid, the interlink infrastructure will also require unprecedented security arrangements and enormous resources, stretching defense and police forces thin. The construction of dams and excavation of thousands of kilometers of canals will cause massive population displacement. Dams will flood towns and canals will make villages disappear by cutting through thousands of kilometers of fertile land, leaving millions to a life of uncertainty. Does the present government have the right to impose these uncertain risks on society? A project that envisages connecting the peninsular rivers will create a human disaster to rival Mohammed Tughlaks shifting of the capital from Delhi to Daulatabad in the fourteenth century


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CHAPTER 4

CASE STUDY: POLLAVARAM PROJECT

4.1 GODAVARI-KRISHNA TRANSFERSThe Godavari River (FiguGre 1) is the second largest river in India, with a catchment area of 312,812 km2 and a long-term average annual surface flow of 110 km3, of which 76 km3 is estimated, as utilizable Cultivable area in the basin is about 18.9 million ha. The already existing Arthur Cotton Barrage, located downstream of the future Polavaram Reservoir site, provides irrigation water to 170,000ha in the lower Godavari Basin. As in other parts of India, the use of groundwater to meet irrigation water demands is also a common practice.


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The Krishna River Basin is the fourth largest in India with a total catchment area of 258,948 km2 and a long-term average annual surface flow of 78km3, of which 58.0km3 is considered to be utilizable (Amarasinghe et al., 2005). The cultivable area in the basin is about 20.3 million ha. Three large irrigation projects are operational in the basin. The Krishna Delta Project near Vijayawada, which is to directly benefit from the Polavaram water transfer, was constructed in 1852 (Figure 1) and designed to irrigate 530,000 ha of land. The Krishna Delta plays a vital role in the rice economy of the nation and, in addition to the major dam, a large number of informal irrigation sources such as groundwater tube wells, tanks and minor reservoirs are spread throughout the area. Due to the massive surface irrigation development and the rapid expansion of groundwater irrigation, the annual river flow at the outlet of the Krishna has decreased to some 36% of its pre-development level, and some studies have reported the closure of the basin (e.g. Biggs et al., 2007).

Several water transfers have been proposed from the Godavari to the Krishna (Smakhtin et al., 2007). Some of these links are planned as parts of much longer transfers from the Himalayas to the Peninsula. The most downstream link Polavaram to Vijayawada (Figure 1)can, however, be seen as a local project, because the main aim of this link is to transfer what is perceived as surplus water from a more water endowed Godavari to an already water-deficient and over-utilized Krishna Delta. Furthermore, the project is expected to reduce informal irrigation and the use of groundwater in the Krishna Basin.


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4.2 POLAVARAM PROJECT DESCRIPTIONFigure 1 shows the proposed project including the site of the Polavaram Reservoir and the command area of the link canal. The project includes two canals, i.e. on the right and left bank of the Godavari River. The PolavaramVijayawada link command area is located on the right bank, with the link canal starting from the proposed Polavaram Reservoir. The climate in the command area of the Polavaram project varies from hot, semi-arid to sub-humid, tropical. The monsoon season (known as Kharif in India) extends from June to October, and the post-monsoon season (known as Rabi) extends from November to March, with a usual annual dry spell from April to May. Average annual rainfall is 1,000mm, with over 80% falling during the Kharif season due to the southwest monsoon. The temperature varies from 448C in May to 228C in December. The overall population density in the command area is 543 persons per km2 with 60% of the population dependent on agriculture

The total cultivable area of the Polavaram link canal is 139,740 ha. Of this area, 71% (99,755 ha) is irrigated by bore wells, tanks and open head channels taking off from the river, and 29% (39,985 ha) is non-irrigated (GOI, 1999b). However, a more recent survey in the Polavaram area (Bhaduri et al., 2007), suggested that almost 95% of cultivated area in the link command area is already under irrigation at present. Therefore, the assumption that a significant new irrigated area will develop due to the implementation of the proposed link canal may not materialize, as the existing Arthur Cotton Barrage in the Godavari, the Prakasham Barrage in the Krishna and lift irrigation from the main river channel supply surface water to the deltas. Most of the new area that, according to the feasibility study from 1999, is to be brought under irrigation is already being irrigated with groundwater, water from tanks or canals. Bhaduri et al. (2007) indicate that 84% of the command area is currently irrigated with groundwater, and 9% with water from canals.


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The Polavaram Project would allow paddy, sugarcane, chillies and pulses to be planted, considering soil suitability, the agro-climatic conditions and local practices (GOI, 1999b). Furthermore, irrigated crop intensity is expected to reach 150%. The current existing cropping pattern in the area is dominated by paddy, sugarcane and tobacco during both the Kharif and Rabi seasons (Bhaduri et al., 2007). Increased upstream development, especially through the construction of reservoirs and irrigation systems in the Krishna basin, has resulted in declining downstream flows, which has affected cropping patterns in the Krishna Delta. When enough water is available, however, two rice crops are grown per year in the Krishna Delta, while in dry years, one rice crop and one less water-intensive crop during the Rabi season is practiced (Biradar, 2007). In the Godavari Delta, two paddy crops are grown. However, in both the Godawari and Krishna deltas, supplemental groundwater use is common practice.

The Project Plan suggests that the main left canal will transfer 3,663 million cubic meters (MCM) of water to meet future irrigation and industrial requirements. The link canal on the right bank will divert 5,325 MCM for irrigation, domestic supply and industry. The planned Polavaram reservoir will have an utilizable storage of 2,130 MCM (GOI, 1999b) and will submerge around 63,000 ha of land, which at present hosts 250 villages with a total population of 145,000


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4.3 METHODS 4.3.1. Overview of the WEAP 21 modelThe Water Evaluation and Planning Model (WEAP), developed by the Stockholm Environment Institute (SEI), is designed to evaluate water resources development and management scenarios associated with changes in biophysical and socioeconomic conditions. In the WEAP model, water supply is defined by the amount of precipitation that falls on a catchment or a group of catchments. This supply is progressively depleted through natural processes, human withdrawals, or enhanced through accumulations/storages. Thus, the WEAP 21 model adopts a broad definition of water demand, where the catchment itself is the first point of depletion through evapo-transpiration. The core of the model is a water balance equation that includes such components as catchment-scale rainfall-runoff processes, groundwater recharge, evaporative demands and surface and groundwater withdrawal and return flows. Water supplies and demands are linked to the stream network and water allocation components via the WEAP 21 interface, which keeps track of water allocations and accounts for groundwater and stream flow depletion and addition .The model optimizes water use in a catchment using an iterative Linear Programming algorithm which seeks to maximize the water delivered to demand sites, according to a set of user-defined priorities. Demand sites are assigned a priority that ranges between 1 and 99, where 1 is the highest priority and 99 is the lowest priority. When water is limited, the model progressively restricts water allocation to demand sites with the lowest priority. More details of the model are available in SEI (2001) and Yates et al. (2009).

4.3.2. SCENARIO FORMULATIONAN ANALYSIS OF THE NATIONAL RIVER LINKING PROJECT

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In order to assess whether the planned water transfer would satisfy the growing water demands in the Polavaram link command area, and also analyze its hydrologic impacts outside of the command area, two main scenarios were simulated:

. Scenario 1Reference Scenario. Current water use under current supply and demand network. The water sources are groundwater and the river channel.

. Scenario 2With the Polavaram reservoir and Link canal. Water supply and demand after the construction of the Polavaram project. The water source is the Polavaram Reservoir and the link canal, ground water and the river channel.

As 95% of the cultivable area is already under irrigation (Bhaduri et al., 2007), it was assumed that substantial increases in irrigated area will not be possible. Therefore, in both scenarios, the agricultural land in the link command area was kept constant. Figure 1 illustrates, in a simplified way, the physiographic setting of the link canal, barrages and right and left bank command areas. In both the Krishna and Godavari Deltas, agriculture is still the major water user compared to domestic and industrial demands (Table 1) and increased agricultural production is the main goal of the Polavaram project. Therefore, the anticipated benefits of building the Polavaram Reservoir and the link canal system are mainly due to improved water supply leading to increases in cropping intensity and yields. The impacts of the Polavaram project were assessed by running the above two main scenarios under different crop rotation systems: i) paddy-paddy, ii) paddy-pulses (representing a low water intensity crop) and iii) sugarcane only. These cropping patterns reflect the regional practice of planting two paddy crops or sugarcane if farmers perceive no water scarcity, and a cropping pattern of paddy during the monsoon and a low water-intensive crop (e.g. pulses, tobacco) during the dry season under water scarce conditions. The domestic, industrial and livestock water demands were kept constant in all runs. Each cropAN ANALYSIS OF THE NATIONAL RIVER LINKING PROJECT

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rotation condition was run with and without the inclusion of environmental flow (EF) requirements. The results of the scenarios were compared and discussed in terms of unmet water demands.

4.3.3. Data and WEAP set up and simulationsThe starting point of the analysis was the development of water demands in the study area: from agriculture, the domestic sector, industry and livestock. Each demand in the model is represented by a demand node. Monthly water demands from each node were assigned a priority level and linked to its available sources of water supply. Domestic water demand was given the first priority, followed by agriculture, industry and livestockin that order.

In the model set up, the link canal command area was divided into subcatchments based on a drainage map extracted from a digital elevation model (DEM). For the 6 sub-catchments that fell under the link command area (labeled R1R6 in tables and figures presented here, though no links are shown in Figure 1), nodes corresponding to agricultural and domestic demand were created. However, as livestock and industrial water demands were very small, only one demand node representing livestock and one demand node representing industrial demand were created for the entire command area. Water demand data were available at mandal level (Indias third-level administrative subdivision after State and District). In the model, however, the sub-catchment represents the hydrological demand unit. Therefore, the mandals in the command area were assigned to the sub-catchments by merging them together using a Geographic Information System (GIS). The demand nodes that were closer to the sources of water supply were given higher priorities.Table 4.1. Water demand for 2003 (MCM; not including loss and reuse) for domestic, industry, livestock and agricultural demand from the catchments within the link command area (R1R6), Arthur Cotton command area and the left bank canal area.


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The agricultural water demand for each sub-catchment was calculated using the FAO Crop Requirements Method option in the WEAP model (FAO, 1998). The domestic, livestock and industrial water demands were calculated using the statistical reports of the Indian Government (GoAP, 2003a, b, c, d). Water demands from outside the link command area (but still to be affected by the proposed water transfer) were also added to the model set up. These additional demands included: . demands from mandals on the left bank command area of the Godavari River (Figure1), based on the quantity of water to be transferred from the left bank canal (GOI, 1999b); . irrigation demands from the Prakasham Barrage; . irrigation demands from the Arthur Cotton Barrage. The Arthur Cotton and Prakasham Barrage irrigation command areas lie in the Krishna and Godavari Deltas, downstream of the proposed Polavaram Reservoir and command area (Figure 1). These additional demand sites were not represented in the model as catchments, but as sites where a fixed quantity of water is abstracted from the sources of supply on a monthly basis. Each demand site was assigned a priority, which determined the water allocation order. In Scenario 1, the Arthur Cotton Barrage command area in the Godavari Delta was given a higher priority than the irrigation demands in the link command area catchments. In Scenario 2, however, theAN ANALYSIS OF THE NATIONAL RIVER LINKING PROJECT

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link command area demands were given a higher priority than the Lower Delta. The sources of water supply that were built into the model were precipitation (for the catchments), surface water and groundwater. Precipitation supply was calculated based on monthly data from a climate station located in the Krishna Delta. Surface water flows in the Krishna and Godavari were obtained from river gauging stations upstream of the Polavaram project. Ground water in the model was represented by a node and water availability was calculated based on the storage capacity and natural recharge values which were based on GoAP (1995, 2006). The maximum withdrawal rates from groundwater were based on the storage capacity and groundwater recharge rates for the area. The Polavaram Reservoir was simulated using the salient features published in the government feasibility report (GOI, 1999b), where the link canal is designed to transfer 5,325 MCM of water per annum. The gross storage capacity of the reservoir is to be 5,511MCM and the live storage is 2,130 MCM. The annual evaporation loss from the reservoir has been estimated to be 989 MCM. The reservoir releases were based on seasonal variations in water demand i.e. more water is transferred during the dry season. The environmental flow requirements were estimated using the method described by Smakhtin & Anputhas (2006). The method takes into account the limitations of available hydrological and ecological information in India at present, but ensures that elements of natural flow variability are preserved in the estimated environmental flow time series, as required by contemporary hydro- ecological theory. The method is based on the use of a flow duration curvea cumulative distribution function of monthly flow time series. The curve is calculated for several categories of aquatic ecosystem protectionfrom largely natural to severely modifiedand the required EF volume and elements of flow variability are set to progressively reduce with the decreasing level of ecosystem protection. The EF calculated for the lowest acceptable category D (largely modified rivers) were used in this analysis. In the model runs with the inclusion of environmental flow requirements, the highestAN ANALYSIS OF THE NATIONAL RIVER LINKING PROJECT

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priority was given to environmental demands. The runs with the inclusion of environmental flow requirements were run with a crop rotation of paddy-paddy and paddy-pulses. Simulations were conducted over the period from June 1991 to May 2005.

4.4 Results and discussions4.4.1. Scenario 1: Reference scenario with current water supply and use Under the current system of water use, the average annual un-met demand for a period from June 1991 to May 2004 in the command area of the link canal is 1,643 MCM for a paddy-paddy system. Figure 2 shows the cumulative monthly average unmet demands for agriculture, domestic use, industry and livestock uses under different simulation runs: paddy-paddy, all sugarcane, paddy-pulse, paddy-paddy with environmental flows and paddy-pulse with environmental flows. The unmet demands occur in all months except July and August (peak of the monsoon). Changing cropping pattern may decrease the unmet demands. For example, planting only one paddy crop during the rainy season and pulses (a low water intensity crop) during a Rabi season decreased water deficits by up to 48% (Figure 2). As expected, giving EF (even very small environmental flow requirements, corresponding to the least acceptable Environmental Management Class D) a high priority in the water allocation scheme, increased the unmet demands for other uses (agriculture, industry, and domestic). The un-met demands are the highest for the simulation that combines a paddy-paddy rotation with environmental flow requirements (Figure 2). Annual demands from the Arthur Cotton Barrage are 8,199 MCM for irrigation and 378 MCM for domestic and industrial use (GOI, 1999b). Assuming these demands and a paddy-paddy cropping system,


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Fig. 2. Scenario 1: monthly average (19912004) unmet demands from agriculture, domestic use, industry and livestock for the subwatershed falling under the link command area for different cropping patterns, and with the inclusion of environmental flows. All cases include conjunctive water use, surface water use and groundwater use.

the mean annual simulated unmet demand for the command area of the Arthur Cotton Barrage in the Godavari Delta is 818 MCM. This constitutes 10% of the mean total annual demands. The model also considered loss and reuse during transmission. Information on groundwater was not available for the areas outside of the Polavaram link command area. Therefore the demands in the model were linked to surface water supplies. Bhaduri et al. (2007) found that groundwater is used in this area. Consequently, the unmet surface water demands at present are probably being met by groundwater extraction. The water deficit in the Godavari Delta is in the Rabi and dry seasons (December to May; Figure 3). There is no deficit in the months from June to November. Therefore, the analysis shows that although there may be surplus water during the Kharif season, in other months there is a deficit in the Godavari Delta which is being met by ground water. In the area supplied by the Prakasham Barrage in the Krishna Delta, the annual total demand is 5,139 MCM (GOI, 1999b). The model calculated 27 MCM of annual average unmet demand after 2003. Similarly, a mean annual un-met demand of 2,057 MCM was calculated for the left bankAN ANALYSIS OF THE NATIONAL RIVER LINKING PROJECT

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command area in the Godavari. Similar to the Arthur Cotton Barrage command area, the water deficit in the left bank command area is only in the Rabi and dry seasons (December to May; Figure 3). In order to check if estimated EF requirements are being met in the Krishna Delta, under present conditions, the EF for Class D were plotted against observed flow from the gauging station at Vijayawada (Figure 4). The Vijayawada gauge is downstream of the Prakasham Barrage (Figure 1). As shown in Figure 4, the situation in recent years has deteriorated as more water is being used upstream for various purposes. Annual analysis for the Godavari showed that during the 14 year modeling period, the EF requirements are not met during the dryer years (based on rainfall data). Figure 5 illustrates that the unmet EF requirements are highest in June, when water demand for agriculture is high. The unmet EF plot shown in Figure 5 is simulated with a paddy-paddy cropping pattern. Delays in the onset of the rainy season will affect water available for EF. Paddy sowing was assumed to start in June. Therefore, if the monsoon does not start in June, irrigation water demand will increase. The EF for class D are met from August to November.

Fig. 3. Scenario 1: monthly average (19912004) unmet demands based on water requirements from the Arthur Cotton Barrage and the Polavaram left bank command area.


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Fig. 4. Class D environmental flow requirements plotted against measured flow from the gauging station at Vijayawada.

4.4.2 Scenario 2 : with the Polavaram reservoir and link canal The simulations with the link canal and reservoir show that there are minimal unmet demands for agriculture, domestic, and livestock requirements within the link command area (Figure 6). Figure 7 shows monthly average unmet demand (for 1991 2004) from agriculture, domestic use, industry and livestock for the link command area under different cropping patterns as well as with EF requirements. The unmet demands occur during the period from January to June, and changing cropping pattern to paddy-pulses almost nullifies the unmet demands which exist under other crop rotations (Figure 7). This is definitely an improvement for the link command area compared with scenario 1 (Figure 2) where the unmet demands are one order of magnitude higher. Introducing EF for downstream Krishna and Godavari, especially coupled with a paddy-paddy cropping pattern, increases the unmet demands during the months from January to June (Figure 7). When comparing these values to Scenario 1 in Figure 2, one can conclude water deficits within the link command area have decreased. However, if EF requirements are included, then there is a deficit in the link command area under a paddy-paddy cropping system. The mean annual unmet demands for the left bank command area and the Arthur Cotton Barrage command area were 799 MCM and 5,270 MCM, respectively.AN ANALYSIS OF THE NATIONAL RIVER LINKING PROJECT

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Compared to Scenario 1, the water deficit is smaller in the left bank command area, but higher in the Arthur Cotton Barrage command area, which is expected since water in the Godavari is being stored and diverted to the Polavaram command area. As with the current situation (Scenario 1), there is a water deficit in the Arthur Cotton command area only in the Rabi and summer seasons (December to May). The situation of un-met demands for the Prakasham Barrage irrigation area shows improvement as there was no water deficit, with the exception of 2003, which was a particularly dry year. This water deficit occurs again only in March and can be alleviated by growing pulses or another low water-intensive crop during the Rabi season. Therefore, analysis with the link canal (Scenario 2) showed that although the pressure on water resources within the left and right

Fig. 5. Scenario 1: unmet environmental water demand under current conditions with a paddy-paddy cropping pattern. Environmental flows are given the highest priority and a paddy-paddy cropping pattern is simulated.

bank command areas reduces, there will be an increased deficit in the Arthur Cotton Barrage command area. This deficit is, however, only during the Rabi and summer seasons.


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4.4.3. Comparing scenario 1 and 2 In the two analyses (Scenarios 1 and 2), demands from the mandals in the link command area were also supplied with groundwater, but due to the lack of groundwater recharge data from the Arthur Cotton Barrage, Prakasham Barrage and the left bank command area, demands were linked to surface water

Fig.6. Scenario2:monthlyaverage(19912005)unmet water demand sundera paddy-paddy crop rotation. Unmet demands in the link command area are minimal compared to those in the Arthur Cotton Barrage area and left bank.

Fig.7.Scenario2:monthly average (1991-2004) unmet demand from agriculture, domestic use, industry and livestock for the link command area under different cropping patterns, and with the inclusion of environmental flows. All cases include conjunctive water use, surface water use and groundwater use.


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availability. In reality, however, some of this un-met demand is met by groundwater. It is possible that increased aquifer recharge due to irrigation in the Polavaram link command area will provide additional groundwater resources for the Lower Delta where the Arthur Cotton Barrage command area is located. However, more studies are necessary to make accurate predictions on the sustainability of groundwater use. A key objective of the Polavaram Project is to reduce groundwater use. Therefore, if there is an increase in the pumping of groundwater in the Lower Delta to maintain the existing agricultural production (due to less water delivered), this objective will not be met and the pressure on the natural aquifers will increase.

Salient features published in the government feasibility report (GOI, 1999b) were used to simulate the storage volumes of the proposed Polavaram reservoir. Published monthly net evaporation was also used to calculate evaporation losses from the reservoir. The reservoir was found to reach the inactive zone (3,381 MCM) during every dry season, which means that the water stored during each monsoon will be utilized during the dry season of that same year. The storage capacity of the reservoir does not provide storage and ensure water for inter-annual variations.

Analysis of the Godavari river flows in the delta showed that during the 13-year modeling period, the EF requirements were not met during June in 1993, 1997, 2000 and 2003. In the simulation, EF requirements were set under a paddy-paddy cropping pattern, where paddy sowing was set to start in June. Therefore, as water demands for agriculture are high during this month, if the monsoon rains (which usually start in June) are delayed then there will be un-met demands for agriculture as well as for EF requirements. In both scenarios, June has the highest un-met EF for the Godavari. The storage in the Polavaram reservoir, as mentioned above, is utilized within each year. Therefore, in this case, the reservoir does not also provide water to compensate for delays in the onset of the monsoon rains.


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4.5 CONCLUSIONIn this study, detailed monthly analysis was done to test the feasibility of the Polavaram Reservoir and water transfer scheme. The study suggests that water resources management in the region has to be done on a seasonal basis by taking monthly variability into consideration. The simulations show that the proposed Polavaram Reservoir and link canal will reduce the seasonal pressure on water resources for the proposed command area of the reservoir. However, this will result in increased water deficits during Rabi and summer months in the Lower Godavari Delta, which is being supplied water through the Arthur Cotton Barrage. Therefore, water deficits may simply be transferred from one area to another. The water deficits exist only in the dry months. Changing cropping patterns, for example by planting paddy during the monsoon season and a low water-intensive crop such as pulses in the dry season in the link command area, will decrease unmet demands for the Lower Godavari Delta. However, this will not be enough to continue the present water use patterns in the Arthur Cotton Barrage command area. A part of the problem is that the storage capacity of the proposed Polavaram Reservoir may not be sufficient to meet the planned irrigation requirements and other demands in the link command area, as well in the Arthur Cotton and left bank areas. Similarly, the need to ensure EF should also be considered in the context of seasonal variability, as it is mostly in the dry months that water allocation problems become critical. In the Godavari, it will not be possible to meet EF requirements in June, just before the start of the monsoon, if the onset of the rainy season is delayed. Meeting EF requirements in the Krishna is a bigger problem than in the Godavari and the situation is not likely to improve even after the Polavaram project, as most of the water that is being transferred will be used for en route irrigation. In this study, the analysis of the water transfer is done purely on hydrological terms, as the main justification for the NRLP is based on the transfer of surplus water to deficit basins. It is, however, also recommended to integrate an economic analysis into the assessment, whereby the benefits of the projects incremental water supplyAN ANALYSIS OF THE NATIONAL RIVER LINKING PROJECT

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can be compared against the losses (e.g. second season rice crop in the Godavari Delta). The planning of water transfer schemes should also look at the land and production loss, displacement costs and other impacts associated with water infrastructure development. While all possible attempts have been made by the authors to acquire the best input data available, it was not always possible and hence a number of assumptions had to be made. Information available on economic and social analysis look similarly fragmented Inter-basin water transfers have been an integral part of water resources management all over the world. However, careful integrated planning and analysis is necessary to ensure that proposed high investment schemes are able to operate as planned and can deliver the expected long-term benefits.

REFRENCESAN ANALYSIS OF THE NATIONAL RIVER LINKING PROJECT

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1. Chambers, R. 1988. Managing canal irrigation: Practical analysis from South Asia. Cambridge: Cambridge University Press. 2. Dasgupta, M. 2003. Experts raise doubts about river linking project. Chennai: The Hindu (January 31). 3. Falkenmark, M. 1989. Fresh water: Time for a modified approach. Ambio 15 (4): 194 200. 4. Garg, S. K. 1999. River water disputes in India. New Delhi: Laxmi Publications. 5. Goyal, J. 2003. Is interlinking of rivers viable? Chandigarh: The Tribune (March 13). 6. Gujja, B. 2003. A civil society dialogue on the subject of Indias proposed interlinking of rivers. Draft for initial consultative meeting on 8 February 2003. Delhi (January 16).


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An Analysis of the National River Linking Project of India

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