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Vol. 11 No.1 January-March 2003

Large dams in Northeast rivers, forests, people and power THE

EcologistVol. 11 No.1 January-March 2003 Asia

3 Large Dams in the Northeast – A Bright Future? Manju Menon, Neeraj Vagholikar, Kanchi Kohli and Ashish Fernandes take a look at some of the many issues concerning large dams in . 9 The , India The Brahmaputra is a unique river system and it is essential to understand it before we attempt to alter it, write Dr. Dulal C. Goswami and Partha J. Das. 15 Rivers An extract from 5000 Days to Save the Planet by Edward Goldsmith, Nicholas Hildyard, Peter Bunyard and Patrick McCully. 19 Lessons From Loktak Ramananda Wanghkheirakpam believes that few cases better illustrate the often disastrous consequences that dams have than the Ithai barrage and its effect on the Loktak wetland and its inhabitants. 25 Tracking a Hydel Project Neeraj Vagholikar and M. Firoz Ahmed are concerned about unanswered questions with respect to the Lower Subansiri project. 33 Saved! The Story of Rathong Chu Manju Menon writes about an anti-dam struggle in Sikkim, where people placed the sanctity of their lands above all else. Founding Editor Edward Goldsmith 34 Clearance of Large Hydel Projects Editor Bittu Sahgal Promode Kant offers a perspective on the clearance procedures that large hydel projects are legally required to pass through. Assistant Editor Ashish Fernandes 38 We should have gone to Court! Editorial Board Dr. Claude Alvares, Ashish Kothari speaks to Ashish Fernandes about his experiences of the Ministry of Smitu Kothari, Dr. Vandana Shiva, Environment and Forest’s official clearance process for dams. Nityanand Jayaraman 40 Stemming the Flood, Killing Biodiversity Guest Editors Manju Menon, Neeraj Vagholikar, Kanchi Kohli Dr. Sanchita Boruah and Dr. S.P. Biswas discuss the impact of flood control devices (members of Kalpavriksh) on the fauna of the Brahmaputra drainage system. 42 Design Umesh Bobade, Ashish Fernandes The Brahmaputra’s Changing River Ecology Dr. A.K. Das says that we need to learn from the traditional knowledge and wisdom Circulation P. Bhaskar of people while dealing with floods. Processing Scana Color (India) Ltd. 44 A Struggle for Homeland and Identity Printing Mudra, Pune Sanat K. Chakraborty writes of the plight of the Hajong and Chakma The Ecologist UK refugees and the social crisis caused by their displacement due to the Kaptai dam. www.theecologist.org 46 Some Proposed and Existing Dam Projects in Northeast India Editor Zac Goldsmith 50 Large Dams and Power Demand Commissioning Editor Simon Retallack Prayas Energy Group reassesses the role of large dams in meeting power demand. Managing Editor Harry Ram 56 The Elephant and The Tragopan Assistant Editor Jeremy Smith We reproduce Vikram Seth’s ecological fable, based on the efforts to save the Dzukou Valley in Nagaland and Manipur from a dam. Sub-editor Jini Reddy 61 Social and Environmental Impacts of Large Dams in India Science Editor Peter Bunyard Shekhar Singh summarises the Indian large dam scenario. Researchers Jim Wickens, Molly 71 Kameng Underestimated! Heinrich, Stephanie Katz The Kameng hydel project in Arunachal Pradesh was granted environmental clearance Art Director Peter Bishop despite glaring errors in the project reports. Signs of destruction are already visible, Editor’s PA Rita Kassai write Dr. Anwaruddin Choudhury and Manju Menon. Editorial Board Helena Norbeg-Hodge, 72 A Geodynamic Perspective of Arunachal Pradesh Steven Gorelick, John Page Dr. K.S. Valdiya talks about the unique geological set-up of Arunachal Pradesh and says that the construction of large dams in this state would not be prudent. The Ecologist Asia is published four times a 76 Tipaimukh year. We welcome contributions and shall Dr. R.K. Ranjan Singh believes that Manipur’s Tipaimukh dam is a death trap for offer reimbursement for material supplied. its indigenous people. We cannot accept responsibility for 80 Taming the Teesta unsolicited material. Reproduction in whole or part, electronically or in print, without Dr. Kalyan Rudra warns that ecological disturbances in the Teesta basin are unwarranted. prior written permission of the publisher is 84 ’s Gumti Dam Must Go strictly prohibited. Views expressed are not Decommissioning the Gumti dam will go a long way in resolving the conflict between necessarily the views of, or endorsed by, the indigenous people and settlers in Tripura, feels Subir Bhaumik. The Ecologist Asia. For back issues contact 87 Meghalaya – Biodiversity Conservation and Dams the Subscription Department, Meghalaya should study linkages between ecosystems and people and learn from the past The Ecologist Asia, before going in for new dams, say Dr. B. Kharbuli, Dr. H. Kayang, Dr. D. D. Nengnong and 602, Maker Chambers V, D.R.M. Buam. Nariman Point, Mumbai 400 021. 91 Tel.: 91 22 22830061/81 Large Dams: A New Policy Framework Fax: 91 22 22874380 The World Commission on Dams’ strategic priorities for a new development approach. E-mail: [email protected] Cover Photo by Debal Sen. 2 Ecologist Asia Vol.11 No.1 Large dams in the Northeast a bright future? by Manju Menon, Neeraj Vagholikar, Kanchi Kohli and Ashish Fernandes

otential to be India’s future powerhouse, said a news report, in by a long chain of international borders. Today the 2,62,000 sq. km. quoting the Department of Development of the North Eastern region (including Sikkim) is linked to the Indian mainland through a PRegion (DONER), prior to the Northeast Business Summit slender 21 km. corridor through north Bengal. held in Mumbai in July 2002. The October 2001 Central Electricity While this enforced isolation may have, for decades, protected the Authority (CEA) ‘Preliminary Ranking Study’ of the nationwide region’s biodiversity from the destructive large-scale development seen potential of hydroelectric schemes gave the highest marks to the elsewhere in the country, it has also been one of the reasons for the Brahmaputra river system. The study claims to have examined northeast’s economic and political neglect. Northeast India is marked by ‘10 major aspects, which play a vital role in the development of hydro socio-political complexities, which include struggles for political projects’1. The 168 schemes2 considered by the ranking study have a autonomy and resulting armed conflicts. The Indian constitution has cumulative installed capacity of 63,328 MW3 and 149 of these were attempted to deal with the northeast’s unique nature by having a system given ranks A and B, indicating high viability. These schemes will be of administration that differs from the rest of the country. The sixth developed by agencies such as the National Hydro Power Corporation schedule and other constitutional provisions relevant to the northeast (NHPC), North Eastern Electric Power Corporation (NEEPCO), the offer different degrees of autonomy and self-management (including Brahmaputra Board and State Electricity Boards and a major portion natural resource management) to indigenous communities. Despite this, of this power will be evacuated to other parts of the country. Other there seems to be little opportunity for participation in the planning of than these large projects, over 900 mini and micro hydel projects have large developmental projects. Faced with a multitude of challenges, the 4 been identified to meet the local needs of the northeast. region is currently charting a course for ‘development’ and large hydel Some of the schemes being planned for the region will be the projects for power export are a part of the development plan. largest hydro projects that India has ever seen and are to come up in The government and proponents of large dams in the region one of its most ecologically-fragile areas. The pace with which these paint a win-win picture: exploiting the country’s largest perennial projects have advanced and the manner in which some of them have water system to produce cheap, plentiful power for the nation, passed through official clearance procedures caught our attention and economic benefits through power export, employment generation, was instrumental in the compilation of this special issue of the end of militancy, flood control and little direct ‘displacement’ of 5 The Ecologist Asia on large dams in northeast India. local communities. Dams are made out to be the panacea for all the Northeast India problems of the northeast. However, northeast India’s unique Northeast India, consisting of the eight states of Assam, Arunachal characteristics and past lessons from large dams are enough reason to Pradesh, Manipur, Meghalaya, , Nagaland, Tripura and critically examine these promised benefits. A close look at some of the Sikkim,6 is known for its biological and cultural diversity and the projects reveal planning based on inaccurate and inadequate unique Brahmaputra river system. The region is home to over one information, legal violations by project authorities, lack of transparency hundred tribal communities and a large percentage of the population and little scope for effective people’s participation in decision-making. is dependent on traditional natural The ecology of Manipur’s Loktak lake has been adversely affected by the Ithai The articles in this issue raise some resource-based livelihoods. Its barrage, endangering traditional livelihoods such as fishing. Ecological and social of these concerns and also give us a strategic location at the confluence concerns must not be ignored in the development plans for the northeast region. glimpse of the environmental of south, southeast and east Asia characteristics of the region, the made it an important gateway procedures involved in developing between the peoples of the region. these large projects, experiences of

British annexation was the ASHISH KOTHARI local people and historical lessons beginning of defined territorial concerning dams, from the boundaries as it became the northeast, the rest of the country frontier of the British Raj. The and the world. partition of the country in 1947 intensified the northeast’s isolation. Environmental aspects The creation of East Pakistan (now Based on its physiography and ) not only disrupted biological composition, the region road and river communications can be broadly differentiated into with commercial centres in the eastern Himalayas, northeast hills undivided Bengal and beyond, and the Brahmaputra plains. Its but also left the northeast hemmed unique situation at the confluence

Large Dams in the Northeast 3 of the Indo-Malayan, Indo-Chinese and Indian biogeographical regions, Dam engineers are quick to point out that a dam will survive a coupled with its physiography has generated a profusion of habitats, magnitude of 9 or 10 on the Richter scale, but even assuming that the which harbour diverse biota with a high level of endemism (species actual structure is able to withstand a powerful tremor, quake-induced found nowhere else). Northeast India is a part of the Indo-Myanmar changes in the river system may have a serious impact on the viability of biodiversity hotspot, one of 25 such hotspots in the world (Myers et the project itself, as several basic paramaters vis-à-vis the regime of rivers al, 2000). Several articles in this issue describe the serious impacts on and the morphology and behaviour of channels may change. The last biodiversity due to dams (and other flood control devices) in the two major earthquakes in the region (1897 and 1950) caused landslides northeast: Boruah and Biswas on dam-related impacts on the fauna of on the hill slopes and led to the blockage of river courses, flash floods due the Brahmaputra, Kharbuli et al on dams in Meghalaya, Choudhury to sudden bursting of landslide-induced temporary dams, raising of and Menon on the Kameng hydel project, Vagholikar and Ahmed on riverbeds due to heavy siltation, fissuring and sand venting, subsidence or the Lower Subansiri dam and Singh on the Tipaimukh dam. Impacts elevation of existing river and lake bottoms and margins and the creation on species such as the Gangetic dolphin and the sangai deer of Loktak of new waterbodies and waterfalls due to faulting. Analysis of the available are also emphasised. It is ironical and worrisome that in a critical scientific data clearly indicates that the neotectonism of the Brahmaputra biodiversity hotspot, one of the weakest links in environmental impact valley and its surrounding highlands in the eastern Himalayas has assessment studies7 for the projects has been the biodiversity aspect. pronounced effects on the flooding, sediment transport and depositional The Brahmaputra river system, by far the largest in the northeast, is characteristics of the river and its tributaries (Goswami and Das, 2002), unique in many ways as Goswami and Das point out (pg. 9). It is which in turn has a bearing on the long-term viability of dams. distinguished by its glacial origins, location in a highly seismic zone, The calculation of sedimentation rates in the Brahmaputra system, heavy and intense rainfall resulting in ‘flashy’ rivers, a high sedimentation essential for estimating the life of dams is yet another challenge. Goswami rate and an intricate link with the ecology of the (wetlands) in the and Das point out: “Rates of bedload transport at Pandu, estimated by plains. This poses challenges to conventional dam building wisdom. sediment discharge formulae, were found to be highly variable and seemingly Rudra takes a more detailed look at the Teesta sub-basin while Singh unreasonable, except for the Laursen’s equation which shows that the rate of describes the system in his article on the Tipaimukh dam. bedload carriage at Pandu is within about 5-15% of the total load in the Talking of the geological set-up of Arunachal Pradesh, Valdiya river. This demonstrates the kind of uncertainties involved in quantifying (pg. 72) says: “Owing to the extremely active geodynamic condition sedimentation processes, essential for designing hydraulic structures including of the terrain, even the slightest tampering with the ecological-geological dams and reservoirs.” Given these inconsistencies, on what basis have balance can initiate environmental changes, likely to assume alarming sedimentation rates been calculated for dams in the Brahmaputra basin? proportions eventually. There is an imperative need for extraordinary Another critical issue that has developed in recent years is the rapid care when it comes to modifying topography by excavation, placing recession of glaciers, which could have significant impacts on river regimes. loads of water and sediments in river impoundments, changing Many of the rivers of the Brahmaputra basin have their origin in glaciers groundwater circulation through road cutting, removing protective in the eastern Himalayas and are sustained by glacial melt, snowmelt forest cover, etc.” While expounding the features of a natural hazard run-off and monsoon rainfall. A 1999 study of the International preparedness programme, he emphasises the need for formulating Commission for Snow and Ice has warned that glaciers in the Himalaya appropriate codes for buildings and civil structures, especially high are receding faster than in any other part of the world and, at present dams, which he terms ‘critical structures’ i.e. their “destruction or severe rates, are likely to disappear by 2035. This would lead to increased damage by a natural disaster would cause such extensive damage that summer flows in some river systems for a few years, followed by a it should not be built even if the chance of hazard is relatively small.” reduction as the glaciers disappear. The information on meltwater yield and its chemical and sediment characteristics 22 major dam projects are planned in the Siang river basin, including the Upper Siang project, which will generate is vital to the safety and maintenance of the 11,000 MW and be India’s largest hydel scheme. hydroelectric installations and reservoirs in the Himalayas (Hasnain, 1996). In recent years, there have been no serious efforts to investigate

FIROZ AHMED the impact of Himalayan glaciers on the hydrological regime and climate in India. High-altitude lakes formed as a result of glacial melt are potentially very dangerous. Moraine dams (created by debris accumulated by glacial action on mountain slopes and valley floors) holding back these waters are comparatively unstable and a sudden breach can lead to the discharge of huge volumes of water and debris. Such Glacial Lake Outburst Floods (GLOFs) cause catastrophic flooding downstream with serious damage to life, property, forests, farms and infrastructure – including dams. In recent years, GLOFs have impacted Nepal, India, Pakistan, Bhutan and China. Satellite imagery reveals evidence of GLOFs having occurred throughout the

4 Ecologist Asia Vol.11 No.1 Himalayas (MDP, 2001). A major GLOF in August 1985 in Nepal caused extensive damage, destroying the Namche hydel project. Another

in June 2000 damaged the Naphtha-Jhakri hydel project, under DEBAL SEN construction in Himachal Pradesh. Yet, shockingly, aspects dealing with glacial melt, GLOFs and associated risks, have not even found a mention in the risk assessments and EIA reports of dams being built in the eastern Himalayan region. One of the arguments for large dams in the eastern Himalayas is as a flood-control measure. Widespread floods are an annual feature in the Brahmaputra basin, particularly in Assam, where they are caused by a combination of natural and anthropogenic factors. The unique geo-environmental setting of the basin vis-à-vis the eastern Himalayas, the highly potent monsoon regime, weak geological formations, active seismicity, accelerated erosion, rapid channel aggradation, massive deforestation, intense land-use pressure and high population growth, especially in the floodplain belt and ad hoc temporary flood control measures are some of factors that cause and/or intensify floods in Assam, according to Goswami and Das. While scientific opinion on the desirability and efficacy of dams in flood-control is divided, there is an increasing consensus on the need to focus on flood management rather than flood control. As Kunda Dixit and Inam Ahmed (1998) say: “Complete flood control in the Himalayan watershed is impossible. Even partial control is an exercise that may be geopolitically, financially and (more importantly) technically problematic.” Flood-control embankments constructed in Assam have been responsible for the shrinkage of feeding and spawning grounds of many prized fish species and the disappearance of many spawn An indicator of the northeast’s biodiversity richness is that nine out of India’s 15 primate collection centres. A sharp decline in the catch of Indian Major Carps species are found in the region, including this endangered hoolock gibbon. What will be is a pointer to the loss of spawning grounds in the Brahmaputra the biodiversity impacts of the over 168 large dams planned in the region? system (Boruah and Biswas, pg. 40). The breaching of embankments has been a major cause for the intensification of the flood hazard in them to migrate into northeast India, leading to conflicts between the recent times. The undesirable consequences of embankments, especially refugees and local communities. The impending loss of homes, lands and in aiding channel aggradation and overbank flooding are clearly visible livelihoods has led to resistance to the Pagladiya project in Assam by the in Assam. Structural measures, mainly embankments, have so far been Bodos and by the Hmars and Nagas to the Tipaimukh project in Manipur. the sole answer to tackling floods. As a long-term strategy for resource India’s experience in Resettlement and Rehabilitation (R&R) utilisation and hazard management, a judicious mix of structural and of project-affected people is abysmal to say the least. Planning non-structural measures with a greater emphasis on the latter should Commission estimates suggest that 21.3 million people were form the core of the watershed-based regional plan, say Goswami and displaced by development projects between 1951 and 1990 alone. Das. A.K. Das, in his article (pg. 42), emphasises the need to learn Other researchers suggest that this is a gross underestimation and the from the traditional wisdom of local people when dealing with floods. actual figure could be well over 40 million. Of the 21.3 million, The important issue of downstream ecological impacts on the 8.54 million (40%) belonged to Scheduled Tribes, which constitute rivers and the beels (wetlands) in the Brahmaputra plains due to proposed only 8% of India’s total population. Only 2.1 million (25%) are dams in the eastern Himalayas has got very little attention. The seasonal reported to have been rehabilitated; the rest were left to fend for inundation of beels by rivers is essential to the nutrient cycle of local themselves.8 Despite this, India does not yet have a national R&R aquatic ecosystems and is crucial for fisheries. This is likely to be policy and law! There exists a detailed law and procedure for land adversely affected by dams. As Boruah and Biswas point out, this will acquisition by the state, the Land Acquisition Act, 1894. This Act has affect the ‘auto-stocking’ of wetlands by riverine species. The profuse provisions for monetary compensation but R&R is not a part of it. pre-monsoon growth of aquatic weeds will also not be ‘flushed out’ by Much of R&R today is in the realm of administrative discretion, the floodwaters. directions and draft policies. Unless strengthened by specific Social aspects provisions of law and policy guidelines, these do not acquire the force Poorly-planned projects in the northeast such as Loktak and Gumti of law. Since the mid-1980s, several drafts of a national R&R policy have had long-term negative impacts. Bhaumik (pg. 84) makes a strong have been doing the rounds but it still awaits finalisation. While case for the decomissioning of the Gumti dam and returning the land to some state governments have R&R policies and laws, this is not the the tribals, which he feels is a crucial step towards the resolution of the case in the northeast. Therefore, we cannot share the optimism tribal–non-tribal conflict in Tripura. Wangkheirakpam (pg. 19) describes expressed by Kant in his article (pg. 34) on the clearance procedures, in detail the socio-economic impacts of the Loktak project on the people regarding official provisions on rehabilitation and their living off and around the lake. The Kaptai dam (pg. 44), built in the implementation. There might be stray cases where rehabilitation may Chittagong Hill Tracts of East Pakistan (now Bangladesh) submerged the have been done sensitively, but since the basic framework itself is traditional homelands of the Hajong and Chakma communities, forcing missing, such cases are fortunate exceptions.

Large Dams in the Northeast 5 While the direct displacement of communities upstream of existing In the Lower Subansiri project, it is proposed to give the project and proposed dams in the northeast may be small in numerical terms as affected families a total of one hectare each, amounting to a total of compared to other parts of the country, downstream impacts are likely to 38 ha. as compensation for 960 ha. of agricultural land (jhum and rice be substantial. Other than a mention of downstream impacts in relation cultivation) that they are losing. There will also be monetary to dam-break disasters, there has been little acknowledgement in project compensation. This is despite all the families surveyed having asked reports and official circles of the loss of livelihoods due to dam construction. for ‘land for land’ to sustain their agricultural livelihoods, while only For example, the Ranganadi stage-I project in Arunachal Pradesh, 23.7% and 21.1% also opted for vocational training and other commissioned in 2002, seeks to divert water from the Ranganadi river by employment respectively.9 It is important to note that besides using a dam and tunnel to a powerhouse on the Dikrong river. This is likely to jhum lands for agriculture, forest fallows are also important for medicinal have considerable social consequences, including livelihood impacts, due plants, wild foods and other forest produce. All this would not be to reduced flow in the Ranganadi and increased flow in the Dikrong. The available once they are displaced. This assumes considerable significance project’s EIA did not address downstream impacts, which were evident in while evaluating the social impacts of dams in the northeast where the construction phase itself, with heavy sedimentation downstream, the both the extent of community-managed commons and the livelihood silt deposits being as much as 15 to 45 cm. in the riverbed. The sediments dependence of communities on these areas is considerable. had been contributed by construction work on the project and attendant infrastructure. As a result, the river started to show abnormal behaviour Large dams in India in its flow and tended to change its course at several places in the plains. In India, the movements against the Narmada, Tehri, Silent Valley The impact of sedimentation was visible almost 100 km. downstream and Koel Karo projects have brought to light the social and ecological of the dam in the form of a decrease in costs of large dams. Although these and other fish population, which has affected the lesser-known movements have addressed the fishing community (Darlong, V. in Sundariyal tribulations of local communities and et al, 1998). ecological losses, they have also raised

The article by Vagholikar and Ahmed ASHISH KOTHARI pertinent questions about the technical (pg. 25) also raises concerns about the viability, economic feasibility and the downstream impacts likely on the Subansiri long-term sustainability of such projects. river with the construction of projects on it. While there are visible movements in the The effects on the natural regulation of water northeast to protest against the impacts of in the beels, which are important for traditional large dams such as Pagladiya and Tipaimukh, fisheries and deep-water rice cultivation, have there are also smaller efforts by individuals found no mention in the EIA report. and groups to raise their concerns and fears It is more than livelihoods when it comes about the impacts of dams, as in the case of to Rounglevaisuo (pg.33), the confluence the Lower Subansiri project. Singh in his of the Tuiruong and Tuivai rivers in article (pg. 61) on the impacts of large dams Manipur, held sacred by the Hmar and in India says, “…there is no process by which other indigenous peoples. While the threat the equity impacts of dams are assessed. This of cultural loss still looms large here in the absence, in itself, highlights the low priority form of the Tipaimukh dam, a project which that equity issues are given by the government, was to come up in the sacred valley of as far as dams go.” He further states: “If the Rathong chu in Sikkim was successfully cost of preventing and mitigating those stalled “to honour the sentiments, religion environmental impacts that can be prevented and culture of the people of Sikkim.” A Naga basket-maker. Natural resource-based livelihoods or mitigated, along with the cost of what Many of the project documents are very important for the tribal communities of the northeast. cannot be prevented or mitigated, are emphasise that parts of the submergence are internalised, perhaps very few of the dams in any case ‘degraded’, as local communities practice jhumming made or under construction would still be economically viable.” (shifting cultivation) on these lands. In the northeast, shifting cultivation We do have provisions such as the Environment Impact Assessment is a major traditional land-use and plays a critical role in the livelihoods (EIA) Notification, 1994, which are mandatory for large hydel projects of people and in maintaining agro-biodiversity. The shortening of and form a “valuable tool and process that can assist in incorporating jhum cycles (the length of the fallow period between two cropping environmental concerns in the planning, implementation and phases) due to a variety of reasons has raised concerns regarding maintenance stages of any developmental activity”. (Darlong, V., 1998). the ecological viability of this farming system, but farmers have rejected But the actual quality of EIA reports, which form the basis of the option of sedentary farming as a long-term solution on environmental decision-making, remains shoddy, to put it mildly. In this issue, the EIA reports of some recent projects such as Teesta, Kameng both ecological and socio-cultural grounds (Ramakrishnan, 2002). There and Lower Subansiri have been severely criticised for their glaring lacunae is an increasing acceptance that jhum will continue to form an and grossly inaccurate data. What is more unfortunate is that some of important part of the agricultural systems of the northeast and these projects have been granted environmental clearance on the basis it is crucial to work at re-establishing sustainability in the system of such reports. For people’s groups and concerned citizens, obtaining (amongst other things through appropriate fallow management inputs information and project-related documents from project proponents and integrated land-use management). In this light, decisions regarding has been a matter of luck. Even today, citizens are denied access to the use of jhum lands for developmental projects should be given very information about projects proposed to come up in their areas. careful consideration. Information sharing has so far mostly been through “unofficial” means.

6 Ecologist Asia Vol.11 No.1 Ashish Kothari, former member of the Expert Committee for Environmentalists and hydrologists have cautioned against the river valley projects appointed by the Ministry of Environment and hasty adoption of this scheme. Ramaswamy Iyer, former Secretary, Forests (MoEF), recalls (pg. 38) that his committee’s recommendations Ministry of Water Resources, says “Every inter-basin transfer must for improving the environmental clearance process for dam projects had necessarily involve the carrying of water across the natural barrier laid emphasis on greater public (especially local community) involvement between basins by lifting, or by tunnelling through, or by a long in the process through compulsory public hearings, mandatory circuitous routing around the mountains, if such a possibility exists”. disclosure of all information in local languages, the search for Lifting such large volumes of water over intervening mountain ranges alternatives to each project, monitoring of conditions, etc., but laments would require enormous amounts of energy. Rather than wasting that most remain unimplemented. The June 13, 2002, scarce resources on such grandiose, impractical schemes, we should amendment to the EIA notification now makes the EIA report a focus on more worthwhile and urgent activities, such as extensive public document. It is imperative that concerned individuals water-harvesting all over the country (wherever feasible) and the and groups access this and other project documents10 and review massive task of rehabilitation of tanks in the south and other similar them critically. The environmental public hearing process, traditional water conservation systems elsewhere (Iyer, 2002). a mandatory part of the environmental clearance procedure, offers an Iyer goes on to warn: “We must disabuse ourselves of the notion that important space for people’s participation in decision-making. Despite the vast waters of the Brahmaputra can be diverted westward or southward. the procedural problems in most public hearings, including those for At best we can think in terms of some minor transfers within the eastern the Lower Subansiri, Kameng and the Teesta Low Dam region.” Dulal Goswami, expert on the Brahmaputra river system, has III projects described in this issue, this provision remains a valuable said that a detailed study encompassing various aspects including social, tool and needs to be used to the fullest. economic and environmental issues need to While access to information and be done before pursuing plans to link the participation in decision-making is crucial, Brahmaputra with other river basins. there is also a need for more fundamental Besides the issues highlighted above, changes in the planning process. Prayas VIJENDRA PATIL a fundamental challenge in the case of Energy Group argues (pg. 50) for the need Himalayan rivers will be in identifying for Integrated Resource Planning (IRP). This what is really ‘water surplus’ in the light of entails integrated planning for all inputs increasing glacial recession and the likelihood necessary for livelihood security – water, land, of reduced flows in future. Glaciologists energy and biomass. IRP also ensures that all wonder if the project will ever meet its available options are included in the planning intended objective of reducing water scarcity exercise and ranked in order of their costs. across the country. “There is no scientific “Adoption of techniques and tools such as database on climate and discharge patterns IRP will halt the undue emphasis on in the Himalayas feeding the major rivers and long-gestation, centralised, bulky and the government should not be euphoric high-cost projects such as large hydel power without involving glaciologists and other projects… We feel that though hydro would experts before putting the multi-crore continue to play a significant role in the mega project into operation,” said Dr. Syed power sector, new large dams seem to have Iqbal Hasnain, Professor at the School of serious limitations. If options suggested by Environmental Sciences, Jawaharlal Nehru rational, integrated planning are opted for, University. “Without a long-term database the role of hydro options other than large involving glaciologists from within the hydro projects will be substantially more country and abroad to conduct a detailed The northeast is a globally recognised biodiversity hotspot, study to check climate signals and monitor significant than today,” opines Prayas. with a high percentage of endemic floral and faunal species. temporal and spatial variations, the project The linking of rivers as presently proposed will prove a disaster, In December 2002, the central government set up a task force to economically and environmentally,” warned Mr. Hasnain.11 interlink rivers, reviving a plan already questioned on account of its The World Commission on Dams economic, technical, political, environmental and social viability. In The World Commission on Dams (WCD)12 was established by 1980, the Ministry of Water Resources (MoWR) had prepared a National the World Bank and the International Union for the Conservation of Perspective Plan (NPP) for optimum development of water resources Nature in May 1998 in response to the large dam debate. Its mandate envisaging inter-basin water transfers from surplus to deficit areas. The was to review the development effectiveness of large dams, assess proposed benefits include flood and drought mitigation, increased alternatives for water resources and energy planning and develop irrigation, hydro power development, etc. To give practical shape to the internationally acceptable guidelines and standards for the planning, linkage proposals, the National Water Development Agency (NWDA) design, appraisal, construction, operation, monitoring and was established in July 1982 to carry out technical studies. The plans decommissioning of dams. The first independent assessment of dams, for Himlayan river development involve the construction of reservoirs the report concluded that “while dams have made an important on the principal tributaries of the Ganga and the Brahmaputra in India, contribution to human development and benefits derived from them Nepal and Bhutan. It also proposes linking canal systems to transfer have been considerable, in too many cases an unacceptable and often surplus flows of the eastern tributaries of the Ganga to the west. The unnecessary price has been paid to secure those benefits, especially in linking of the main Brahmaputra and its tributaries with the Ganga and social and environmental terms, by people displaced, by communities the latter with the Mahanadi was also being mooted. (MoWR 2002). downstream, by taxpayers and the natural environment.”

Large Dams in the Northeast 7 The WCD report stated that the economic benefits from big 3. 26,201.4 MW at 60% load factor. dams are grossly inequitable, excluding poorer sections, mainly tribal 4. In June 2002, former Union Minister of Power, Suresh Prabhu announced in Guwahati that 914 micro and mini hydel projects had been identified for the communities and women, from a share in these benefits. The last northeastern states ( ‘914 micro hydels to light N-E’, Indian Express, June 5, quarter of the 20th century saw a gradual shift in opinion with reference 2002). This figure does not include Sikkim. There are slight variations in the to large dams. Globally, the construction of new dams has fallen by data available with various sources. 60% since the 1970s. Additionally, dams which are not serving their 5. This issue has largely focussed on hydro power projects as they constitute the majority of dams being proposed for northeast India. Hydro power generation purpose or are too expensive to maintain are being decommissioned is also a large component of multipurpose projects proposed for the region. and there is an increasing momentum towards river restoration. Even 6. Sikkim is a recent addition to what is referred to as the northeast – the the argument that hydro power is a clean energy option has been other seven states. Since we have used the Brahmaputra river system as the dispelled as reservoirs have been found to emit greenhouse gases. reference point, this issue contains an article on the Teesta sub-basin, which extends over Sikkim and northern portions of West Bengal. The historical Despite the MoWR rejecting the WCD report, the study merits perspectives on the northeast in this piece may not be relevant to Sikkim and careful attention. While one may disagree with aspects of the report, North Bengal. the approach to decision-making that it proposes will strike a chord 7. Under the EIA Notification, 1994, it is mandatory for dam projects costing with all who believe in ecological and social justice. The WCD proposes over 100 crores to undergo site and environmental clearance from the Ministry of Environment and Forests. The preparation of the EIA report is an important a new way forward based on a ‘rights and risk’ approach. This approach part of this process. to decision-making is based on recognising the rights of, and assessing 8. Address given by Dilip Singh Bhuria, Chairman, National Commission for Scheduled the risks to, all stakeholders. This means that all stakeholders whose Castes and Scheduled Tribes, at the National Meeting on Community Forestry Issues rights might be affected and all stakeholders who have risks imposed organised by the World Bank, Manesar, Haryana, November 8-9, 2001. 9. ‘Rehabilitation and resettlement measures’ in the section on socio-economic upon them involuntarily, should be included in the decision-making aspects in the EIA and EMP report for Lower Subansiri project prepared by process. The WCD developed seven strategic priorities for this new Water and Power Consultancy Services (WAPCOS), Gurgaon, Haryana. approach to development (see pg. 91). 10. For large power projects it is necessary under section 29 of the Electricity (Supply) Act, 1948 to publish in the Official Gazette of the state concerned and A bright future? in local newspapers, information about the project and give a minimum of two Two regional consultations on ‘Dams and Development’ were months to people to make representations. If the Detailed Project Report is not held in the northeast and neighbouring areas recently. One was made available during this period, it should be demanded, since making representations on the scheme requires access to sufficient information on the organised by the Citizens’ Concern for Dams and Development project. This notice is usually published before submitting the scheme to the (CCDD), Manipur, in July 2001 at Mawlein, Meghalaya and the Central Electricity Authority for its concurrence. other by NESPON in April 2002 at Siliguri, North Bengal, in 11. Deccan Herald, December 7, 2002. collaboration with South Asia Network on Dams, Rivers and People 12. www.dams.org (SANDRP). Most of the participants in these consultations were of References: 1. Darlong V.T. 1998. Environmental Impact Assessment in Northeast India: A case the view that decisions regarding future dam projects in the region study of river valley projects, Perspectives for Planning and Development in Northeast India, must be preceded by answers to pertinent questions such as: Have the G.B. Pant Institute of Himalayan Environment and Development, Himavikas Occasional Publication, Sundariyal. R.C., Shankar Uma, Upreti T.C. (eds.), No. 11(1998), development needs and objectives been formulated through an open pp. 277-289. and participatory process at local and regional levels? Has a 2. Dixit, Kunda and Ahmed, Inam, Managing the Himalayan Watershed: A flood of questions, comprehensive options assessment for water and energy resource Economic and Political Weekly, Vol. XXXIII No. 44, October 31, 1998. 3. Glaciers Beating Retreat, Down to Earth, Vol. 7, No. 23, April 30, 1999. development been done? Have the social and environmental factors 4. Fernandes, Walter and Paranjpye, Vijay (eds.), 1997, Rehabilitation Policy and Law in been given the same significance as techno-economic aspects in assessing India: A Right to Livelihood, Indian Social Institute, New Delhi. 5. Goswami D.C. and Das, P.J., 2002, Hydrological Impact of earthquakes on the options? Do we have a basin-wide understanding of the ecology of Brahmaputra river regime, Assam: A study in exploring some evidences. Proceedings of the the rivers and the dependence of local communities on them? 18th National Convention of Civil Engineers, November 9-10, 2002, Institution of Engineers At least two-dozen large dams in the northeast are at an advanced (India), Assam State Centre, Guwahati, pp. 40-48. 6. Hasnain 1996. Himalayan Glaciers: A Sustainable Water Resource, ENVIS Newsletter stage of planning or clearance. The above questions need to be asked Vol. 2. No.3, November 1996, ENVIS Centre, Jawaharlal Nehru University. and answers found without compromising on detail. Ushering in these 7. Iyer 2002. Linking of rivers: Judicial activism or Error?, Economic and Political Weekly, projects without adequately addressing these fundamental concerns November 16, 2002. 8. Kothari, A. 2000. Environmental Aspects of Large Dams in India: Problems of cannot justifiably be a way out of the northeast’s development dilemmas. Planning Implementation and Monitoring in EIA Quarterly Issue No. 9. September 2000, Decisions taken at this stage will determine how bright the future of the The British Council.  9. Mountain Development Profile No. 2, September 2000, Glacial Lakes and Glacial Lake northeast – its people and its environment – will really be. Outburst Floods, ICIMOD. Manju Menon ([email protected]), Neeraj Vagholikar ([email protected]) 10. Annual Report 2001-2002, Ministry of Water Resources, Government of India. and Kanchi Kohli ([email protected]) are members of Kalpavriksh, 11. Myers, N., Mittermeier, R.A., Mittermeier, C.G., da Fonseca, G.A.B. and Kent, J. 2000, Biodiversity hotspots for conservation priorities, Nature, 403, pp. 853-858. an environment action group and guest editors of this special issue. 12. Nongbri T., Forest Policy in North-East India, Indian Anthropologist, Vol. 29, Ashish Fernandes is Assistant Editor of The Ecologist Asia. No. 2, December 1999. 13. Pawar, S. and Birand, A., 2000, A survey of amphibians, reptiles and birds in Endnotes: Northeast India. CERC Technical Report No. 6, Centre for Ecological Research and 1. These include hydropotential of the scheme, type of scheme (viz. storage Conservation, Mysore. type, height of the dam, length of head-race tunnel or channel), R&R aspects, 14. Ramakrishnan, P.S., 2002, Land Use Dynamics and Sustainable Development in international and inter-state aspects, accessibility to site, status of upstream or Arunachal Pradesh, Arunachal Pradesh: Environmental Planning and Sustainable Development, downstream development and status of the project. Ecological and geological Himavikas Occasional Publication No 15, G.B Pant Institute of Himalayan Environment aspects, which are crucial in the fragile northeast do not feature in the preliminary and Development, Almora, India, Sundariyal, R.C., Singh, T. and Sinha, G.N. (eds.), ranking study, which has given the highest marks to the Brahmaputra river pp. 67-85. 15. Ramesh M.K. (undated). Legal notings on involuntary displacement, rehabilitation and large system. As per the CEA report, after additional inputs (such as environmental dams. http://www.ceeraindia.org. The Centre for Environmental Law Education, Research impact assessment, seismicity, etc.), the “ranking of schemes as established in and Advocacy of the National Law School, Bangalore. this study may undergo minor changes at the time of final detailed studies.” 16. Experts moot survey before river interlink, Telegraph, November 4, 2002. 2. Out of 226 schemes, 168 schemes each above 25 MW were considered for 17. WCD, November 2000, Dams and Development: A New framework for Decision the ranking study. For a complete list see pg. 48. Making, Earthscan Publications, VA.

8 Ecologist Asia Vol.11 No.1 The Brahmaputra River, India Dulal C. Goswami and Partha J. Das examine the eco-hydrological context of water use in one of the world’s most unique river systems.

he Brahmaputra is one of the world’s largest rivers, with a drainage area of T580,000 sq. km. (50.5% in China, 33.6% in India, 8.1% in Bangladesh and 7.8% in Bhutan). In India, its basin is shared by Arunachal Pradesh (41.9%), Assam (36.3%), Meghalaya (6.1%), Nagaland (5.6%), Sikkim (3.8%) and West Bengal (6.3%). Originating from the great glacier mass of Chema-Yung-Dung in the Kailas range of southern Tibet at an elevation of 5,300 m., it traverses 1,625 km. in China and 918 km. in India, before flowing 337 km. through Bangladesh and emptying into the Bay of Bengal through a joint channel with the Ganga. A unique river, it drains such diverse environments as the cold dry plateau of Tibet, the rain-drenched Himalayan slopes, the landlocked alluvial plains of Assam and the vast deltaic lowlands of Bangladesh. In the plains of Assam and Bangladesh, the Brahmaputra flows in a highly braided channel marked by the presence of numerous mid-channel and lateral bars and islands, while in the Himalayan section its channel is steep and narrow with gradients as high as 14.8 m./km. An extremely dominant monsoon interacting with a unique physiographic setting, fragile geological base and active seismo-tectonic instability together with anthropogenic A satellite image of the Brahmaputra, showing the river’s course through the Assam plains and into the Bay of Bengal. factors have moulded the Brahmaputra into one of the world’s most intriguing gigantic gradient of the Brahmaputra river is as steep as Bangladesh. The northern and southern fluvial system (Goswami, 1985; Ives and 4.3 to 16.8 m./km. in the gorge section upstream tributaries differ considerably in their Messerli, 1989). of Pasighat, but near Guwahati it is as flat as hydro-geomorphological characteristics owing 0.1m./km. (see figure on page 11). The dramatic to different geological, physiographic and Geo-environmental framework reduction in the slope of the Brahmaputra as it climatic conditions. The north bank tributaries The Brahmaputra basin represents a cascades through one of the world’s deepest generally flow in shallow braided channels, unique physiographic setting vis-à-vis the gorges in the Himalayas before flowing in to the have steep slopes, carry a heavy silt charge and eastern Himalayas: a powerful monsoon rainfall Assam plains explains the sudden dissipation of are flashy in character, whereas the south bank regime under wet humid conditions, a fragile the enormous energy locked in it and the tributaries have a flatter gradient, deep geologic base and active seismicity. Flowing resultant unloading of large amounts of meandering channels with beds and banks eastward for 1,625 km. over the Tibetan sediments in the valley downstream. Two rivers, composed of fine alluvial soils, marked by a plateau, the Brahmaputra, known there as the the Dibang and the Lohit, join the upper course relatively low sediment load. Many of the north Tsangpo, enters a deep narrow gorge at Pe of the Brahmaputra, known as the Dihang (or bank tributaries are of Himalayan origin fed (3,500 m.) and continues southward across Siang) river, a little south of Pasighat and the by glaciers in their upper reaches, e.g. the the east-west trending ranges of the Himalayas, combined flow, hereafter called the Subansiri, the Jia Bharali and the Manas. The viz. the Greater Himalayas, Middle Himalayas Brahmaputra, flows westward through Assam Debang and the Lohit are two large tributaries and sub-Himalayas before debouching onto for about 640 km. until near Dhubri, where it emerging from the extreme eastern flank of the the Assam plains near Pasighat. These different abruptly turns south and enters Bangladesh. Himalayas, while the Jiadhal, the Ranganadi, geo-ecological zones have a distinctive In the course of its 2,880 km. journey, the the Puthimari, the Pagladiya, etc. are major rivers assemblage of topographical, geological, Brahmaputra receives as many as 22 major having their sources in the sub-Himalayas, the climatological and floral characteristics. The tributaries in Tibet, 33 in India and three in latter two in Bhutan. Among the south-bank

The Brahmaputra River, India 9 rainfall over the basin varies from 1,200 mm. in The Brahmaputra’s global rank in terms of discharge and sediment yield parts of Nagaland to over 6,000 mm. on the River Average discharge River Sediment yield southern slopes of the Himalaya. The Himalayas at mouth (103 m3s-1) (tons km-2yr-1) Amazon 99.15 Yellow 1,403 exercise a dominating influence on the prevailing Congo 39.66 Brahmaputra (at Bahadurabad) 1,128 weather of the basin due to their location in the Yangtze 21.80 Brahmaputra (at Pandu, Assam) 804 path of the southwest monsoon. Rainfall in the Brahmaputra 19.83 Irrawaddy 616 Himalayan sector averages 500 cm. per year with Hwang Ho 19.83 Yangtze 246 the lower ranges receiving more. A gradual Yenisei 17.39 Mekong 214 increase in rainfall from the valley bottom Mississippi 17.30 Orinoco 212 Orinoco 17.00 Colorado 212 towards the lower ranges followed by a decrease Lena 15.49 Missouri 159 towards the higher ranges is evident from the Parana 14.90 Amazon 46 annual rainfall at Dibrugarh (2,850 mm.) in Irrawaddy 13.56 Indus 103 the far eastern part of Assam valley, Pasighat Ob 12.49 Mississippi 64 (5,070 mm.) in the foothills and Tuting Ganga 11.67 Nile 37 (2,740 mm.) further up the Himalayas. Source: Goswami, D.C., 1985 Monsoon rains from June to September account for 60-70% of the annual rainfall in the basin, tributaries, Burhidihing originates near the venting, elevation of existing river and lake bottoms while the pre-monsoon season from March Nagaland-Myanmar border, the Dhansiri and and margins, creation of new water bodies and through May produces 20-25% of the annual the Dikhow in the Naga hills, the Kopili in the waterfalls due to faulting (Goswami and Das, rainfall. Snowfall is experienced in the Karbi plateau while the Kulsi and the Krishnai 2002). The earthquake of 1950, for example, Brahmaputra basin in areas with elevations of flow from the Meghalaya hills. raised the bed level of the Brahmaputra at 1,500 m. and above. There are altogether Due to the colliding Eurasian (Chinese) Dibrugarh by at least three metres leading to 612 glaciers in the Brahmaputra basin of which and Indian tectonic plates, the Brahmaputra increased flood and erosion hazard potential in 450 are in the Teesta sub-basin of Sikkim while valley and its adjoining hill ranges are seismically the river (see figure on pg. 12). 162 are in the (upper Jia Bharali) very unstable. The earthquakes of 1897 and Soils in the lower Himalayan ranges consist sub-basin of Arunachal Pradesh. 1950, both of Richter magnitude 8.7, are mainly of sands with an admixture of cobbles Ecological base among the most severe in recorded history. and boulders and have a lower erosion The outstanding feature of the These earthquakes caused extensive landslides threshold. The Brahmaputra valley is made Brahmaputra basin is the great diversity of flora and rock falls on hill slopes, subsidence and up of alluvial soils formed on recent river and fauna and their enormous variation in both fissuring in the valley and changes in the course deposits called ‘new alluvium’. There are a few vertical and horizontal distributions. While and configuration of several tributary rivers as isolated pockets of Pleistocene deposits called extraordinary luxuriance and great diversity in well as the main course. In fact, the region’s ‘old alluvium’ within the valley, along the vegetation mark the monsoon-dominated wetter active seismicity has a significant impact on foothills and in parts of Bangladesh. parts, the ice-covered mountain-tops and other the hydro-geomorphic regime of the rain-deficient areas with thin soil cover exhibit Brahmaputra system of rivers, causing Climate regime vegetation that is strikingly sparse or completely landslides that result in the natural damming The Brahmaputra basin, excluding the absent (Goswami, 1997). Recent satellite of rivers, flash floods due to the bursting of Tibetan portion, forms an integral part of the surveys indicate that the Brahmaputra basin, as landslide-induced temporary dams, raising of southeast Asian monsoon regime with a mean a whole, has a forest cover of about 14.5%, riverbeds by siltation, fissuring and sand annual rainfall of 2,300 mm. Distribution of grasslands occupy about 44%, agricultural lands The Brahmaputra’s banks are largely unstable and easily susceptible to erosion. about 14%, cropland/natural vegetation mosaic 12.8%, barren/sparsely vegetated land 2.5%, water bodies 1.8%, snow and ice 11%, urban land 0.02% and permanent wetlands 0.05%. The total forest cover of the Brahmaputra basin SANCHITA BORUAH in India is 1,14,894 sq. km. i.e. 54% of the total area. The distribution of forest cover in the different states within the Brahmaputra basin is as follows: Arunachal Pradesh (82.8%), Nagaland (68.9%), Meghalaya (63.5%), Sikkim (38.1%), West Bengal (21.4 %) and Assam (20.6 %). As a whole, the eastern Himalaya is more humid, its climate more conducive to tree growth with a relatively higher tree line (average 4,570 m.) compared to the western and central Himalayas. Recent satellite surveys indicate a considerable decline in forest cover due to deforestation, land-use conversion and land

10 Ecologist Asia Vol.11 No.1 The hydrological regime of the river Water and sediment yields of the Brahmaputra and some major tributaries responds to the seasonal rhythm of the River/Tributary Drainage area (km2) Water yield Sediment yield monsoon and freeze-thaw cycle of the (m3s-1km-2) (tons km-2year-1) Himalayan snow. With an average annual Brahmaputra at: discharge of 19,830 m3s-1 (cubic metre per Tsela D’Zong (China) 1,91,222 0.0105 100 second or cumec) at its mouth, the Brahmaputra Pasighat (India) 2,44,700 0.0231 340 Pandu (India) 5,00,000 0.0306 804 ranks fourth among the large rivers of the world Bahadurabad (Bangladesh) 5,80,000 0.0331 1128 (see table on pg. 10). In terms of water yield per Dibang 12,120 0.1066 3765 unit discharge area, the Brahmaputra leads other Lohit 22,077 0.0709 1960 major rivers, the rate for the catchment upstream Subansiri 27,400 0.0756 959 of Pandu being 0.0306 cumecs/sq. km. Water Jia Bharali 11,300 0.0858 4721 yields of some of the tributaries of the Puthimari 1,787 0.0403 2887 Pagladia 383 0.1087 1883 Brahmaputra such as the Subansiri, Jia Bharali Manas 36,300 0.0232 1581 and Manas rivers are as high as 0.076, 0.086 Burhidihing 4,923 0.0788 1129 and 0.023 cumecs/sq. km. respectively (see table Desang 3,950 0.0382 622 alongside), surpassing many of the world’s major Dhansiri 10,240 0.0184 379 rivers (Goswami 1998). High monsoon rainfall Kopili 13,556 0.0182 230 in the upper catchments and steep gradients are Source: Goswami, D.C., 1998 considered to be the major factors responsible for the high rates of unit discharge, which in degradation. Shifting (jhum) cultivation, which extremely rich in cultural diversity, with turn help generate the high sediment yield from is widely practised in the northeastern region a great multitude of ethnic, socio-cultural the basin and contribute significantly towards and Bhutan is a major cause of deforestation and linguistic groups occupying their causing drainage congestion in the valley. and has a disastrous impact on the region’s unique habitats and ecological niches. The Brahmaputra is characterised by ecology through soil erosion, loss of soil fertility, The spatial distribution and density marked seasonality and high variability of daily falling crop yields, lowering of groundwater of population is quite uneven in the flow. The highest recorded daily discharge in recharge, increase in surface run-off, sinking of basin, with the highest density of the Brahmaputra at Pandu was 72,726 cumecs the groundwater table and acceleration in the 828 persons/sq. km. recorded in the in August 1962 while the lowest was rates of sedimentation in rivers and reservoirs Bangladesh portion, followed by India 1,757 cumecs in February 1968. The discharge downstream ultimately leading to a significant (143 persons/sq. km.), Bhutan (26 persons/ in the river between summer high flows and rise in riverbed levels and intensification of sq. km.) and Tibet (6 persons sq. km.). winter low flows fluctuates, on an average, by flood hazards. Hydrological regime 12 times although in certain years it has been The Brahmaputra basin provides a unique as high as 20 times (Goswami and Das, 2003). habitat for an exquisite variety of fauna, The hydrological regime of the The mean annual flood of the river, including many rare and endangered species. Brahmaputra is characterised by an extremely Among these, the great Indian one-horned large and variable flow, enormous rates of 48,200 cumecs, has a recurrence interval of rhinoceros, pygmy hog, hispid hare, Asiatic sediment discharge, rapid channel aggradations, 2.2 years, while the maximum recorded flood elephant, clouded leopard, marble cat, golden accelerated rates of basin denudation and unique of 72,726 cumecs is likely to be repeated once cat, binturong, hoolock gibbon, White-winged patterns of river morphology. in about every 133 years. The enormously large Wood Duck, Bengal Florican, etc. are gravely endangered. The eastern Himalayan region is already identified as one of the most threatened biodiversity hotspots of the world. The northeastern region, especially the floodplains of the Brahmaputra, is dotted with a large number of wetlands or beels, which possess tremendous ecological significance as unique habitats for an exquisite variety of flora and fauna. The beels function as floodwater retention basins and traditional fisheries. Over 3,500 such wetlands have been identified in Assam, of which 177 are more than 100 ha. in size. Most of the wetlands are now degraded while a considerable number have been totally destroyed due to siltation, eutrophication, harmful land-use practices and encroachment for settlement, construction of roads, railways, embankments, etc. The Brahmaputra basin, with a total Slope profile of the Brahmaputra river human population of about 75 million, is also

The Brahmaputra River, India 11 Sediment load and flow materials and the vigorously dynamic flow of discharge in tributaries and the Brahmaputra have rendered its