A river at disequilibrium

The Kosi breach
The Kosi River breached its manmade embankment on 18 August. Nearly four million people were displaced in what must be considered one of the larger humanitarian disasters of the last few years – worldwide, not just in the Subcontinent. And yet, we have the singular ability to forget eastern Bihar as the largest and poorest concentration of population anywhere. There is an urgent need to address the rehabilitation needs of this mass of humanity, even as the time comes to decide on what to 'do' with the Kosi. Do we live with the flood, or do we build engineering works? What are the challenges? The three articles in this Kosi-focused package mull over these issues. They are shortened versions of articles carried immediately after the Kosi breach of 18 August on our website, himalmag.com.

– Editors

A River in disequilibrium
On 18 August, there was a breach at Kusaha, on the eastern embankment above the Kosi Barrage in eastern Nepal. Water flowed out first to impact on the adjacent Sunsari District of Nepal. As the breach widened into a two-km stretch and the water gushed out, the inundation displaced people in seven districts of northern and central Bihar (Araria, Katihar, Khagaria, Madhepura, Purnia, Saharsa and Supaul), all the way south to the Ganga.

This ongoing crisis is a manmade technological tragedy first and foremost, and additionally an issue of crossborder inundation that has a bearing on India-Nepal relations in the days to come. Doubtless, the interventions for the future must be based on humanitarian considerations relaating to the lives of the millions who live in what is known as the Kosi's 'inland delta' in Nepal and Bihar. They must also rely on practical solutions based on a full understanding of the nature of the flow of Himalayan rivers, and the possibilities and limitations of purely engineered interventions.

The Kosi Barrage is a child of the Nehruvian dream that drove the great infrastructural projects after Indian Independence, which relied on engineering advances to pull India out of poverty. Dams, declared Jawaharlal Nehru, were the temples of modern India, and the Kosi Project was one of the earlier interventions to put this dictum into practice. What Nehru could not have known was that the barrage-building knowledge of an engineering fraternity based on the non-silting rivers of Europe and North America might not be appropriate for the Kosi.

The Kosi was barraged at Bhimnagar on the Nepal-India border, the task of management entrusted to the Government of Bihar. Kilometres of embankments were built on both sides upstream of the barrage (known as the 'eastern and western afflux bund') to guide the water to the barrage, there to feed two large irrigation canals. Downstream, another 125 km of levees charged southwards on either side to safeguard eastern Bihar from floods.

Over the last 50 years, the silt continued to flow as a natural phenomenon. Confined by the embankments, and having slowed down after it entered the plains at the point known as Chatara, the Kosi deposited its silt load on its bed. Earlier, of course, much of it would have been spread over the surrounding lands. A crisis was brewing as the relentless and natural deposition of silt continued. The Kosi began to flow on a plateau inside the embankments, with the riverbed said at places to be up to five metres above the outlying plains of Nepal and Bihar.

Year after year, even as the 'flood mafia' in Bihar continued to reap crores from the annual ritual of supposedly strengthening the levees, the silt continued to add to the riverbed. On its raised tableland within the walls, the Kosi had achieved a state of disequilibrium in more ways than one. Something had to give.

The engineers and managers of the Kosi Barrage must have known that they were riding a tiger. The Kosi was becoming more unstable by the year, and yet no one dared come up with a thought-through solution. Diverting and distributing the water elsewhere along the old channel(s) of the Kosi would be a complex technical and social-engineering exercise, while the other option would be letting the silt envelope the Kosi Barrage. It was not at all clear that a high dam and massive reservoir upstream in the Nepali valleys would provide any solution.

Photo: Arpan Shrestha

Bihar calamity
Over the course of history, as its riverbed accumulated sediment in the natural course, every few decades the free-flowing Kosi would burst its banks and find a different path at least part of the way down to the Ganga. Over the century before 1955, the Kosi had shifted about 115 km westwards from where the Teesta flows today into Bangladesh. Because of the lay of the land, the river was said to be preparing to move back like a pendulum when it was straitjacketed by the barrage project.

In terms of the proximate cause of the breach, a part of the eastern afflux bund upstream from the barrage seems to have weakened over the past year, but maintenance was not done over the winter and spring as was generally the practice. In early August, the inhabitants of nearby villages had seen erosion of the bund, and alerted the authorities. The political turmoil in Nepal leading to lack of effective state apparatus and the continuous transport blockages may have been contributory, as also a deadlock between the embankment maintenance contractors and newborn local political forces within Nepal wanting a share of the contracting spoils. For all this, the primary responsibility to see that all was well lay with the Bihar-based managers and engineers of the Kosi Barrage, who incidentally enjoy extraterritoriality within Nepal.

Whatever the mix of action and inaction that finally triggered the event, a weakened levee was allowed to give way in mid-August, even before the flood season had arrived. Inundation spread quickly into Sunsari District, as the water sought outlet towards the Ganga, more than a 100 km to the south. The bulk of the suffering, however, was reserved for the population in the seven districts of Bihar, by now accustomed to living protected by the embankments and accordingly having made adjustments in livelihoods and built infrastructure.

This is a calamity whose full dimension will only be understood in the days ahead, but the number of people displaced over the first fortnight was four million. The count of those who have died is sure to be far above the official figures. The raised roadways, which at other times stand accused of constricting drainage, seem to have been lifelines for the fleeing population, even when the asphalt was underwater. Amidst all this, with the state of Bihar reeling, the unprepared and inadequate response of both New Delhi and Patna to the catastrophe is starkly evident.

The first question that remains unanswered as of this writing is whether this is a diversion of the entire mainstream of the Kosi. In which case, will the river consolidate on its new course over the remaining months of September and October, including the peak flood season? Even as we speak, the Kosi is scouring a path along one of its old channels on its way to the Ganga, in a way that might make it difficult to bring it back through a 'river training' exercise.

A great humanitarian challenge will confront Bihar if indeed the river has permanently shifted course and cannot be brought back over the coming year. The effort at rehabilitation, as things stand, would have to be massive as the population waits for the waters to recede in the months ahead. The homes and livelihoods of millions of rural India's poorest population stands destroyed, and upon return they will find the fields rendered uncultivable for a while. The needs of long-term rehabilitation would be simply unimaginable if the course-shift were to be permanent – in this, Southasia's mostly densely inhabited region. In all of this, it is important to remember the nearly 10 lakh villagers who have lived within the embankments of Kosi. It is this ignored population that has suffered the most over the decades as a result of the Kosi Barrage project. The living conditions of these embankment inhabitants would ironically be eased if the river were to go elsewhere.

About the silt
The annual ritual accompanying the yearly flood season has been for politicians in Patna to move into the 'blame Nepal' mode, knowing full well that with the receding waters the clamour would die down and hard decisions could be pushed back another year. Knowing this, the authorities in Nepal too have been lax in enlightening the Bihar and Uttar Pradesh public of two points: first, that Nepal does not have any dam or reservoir from which impounded water can be 'released' to flood the plains; and second, that the two barrages that do exist, on the Narayani (Gandak) and Kosi, are meant merely to divert waters into irrigation canals that exclusively serve downstream India. These barrages do not come with storage reservoirs, and do not have the potential to flood; and in any case, the sluice gates are controlled by Indian administrators.

The long-term solution proposed by India's water bureaucracy to resolve the problems of the Kosi flood has been the construction of a massive high dam above Chatara, where the huge river, having collected water from all of its seven tributaries, enters the plains. As the plan goes, the reservoir would impound an immense volume of water, useful for flood prevention, irrigation and hydropower. But the downside to the proposal, according to activists in Nepal and Bihar, are numerous. The reservoir would inundate populated farmlands in the hills; there is the matter of earthquakes in a region wracked by high-energy tremors; the loss of fertility-through-silt in Bihar; and the neglect of cheaper and more feasible options of 'living with the flood'. On the whole, the activists maintain that the proposed high dam would reflect ecological folly and an inability of officialdom to learn from history.

Beyond the pros and cons of the high dam, one matter that would have to be addressed by the planners and dam-builders relates to the silt-load of the Kosi, which after all was the underlying cause of the August 2008 breach. How would the high-dam project cope with the silt that would accumulate in the reservoir? The impounded lake would quickly become a receptacle for silt, sand and debris of massive quantity, especially in the event of severe cloudbursts upstream (a largely unstudied phenomenon in the Himalayan context). Bear in mind that the dam would impound more silt than the Kosi Barrage embankments, because in the case of the latter a large volume did flow on to Kursela, where the Kosi meets the Ganga. A reservoir, on the other hand, would act more like a Kosi silting pond.

It might take four decades or six decades, but what would be the response when, sometime in the latter half of the 21st century, the Kosi reservoir had become filled with silt to the point where it had become redundant? How does one decommission a high dam and reservoir that have been made inoperable due to sedimentation? And what of downstream flooding that would increase with time, due to the diminished reservoir capacity?

A high dam on the Kosi is what many activists consider a 'technical quick-fix', one that would be the darling of the engineers, administrators and politicians. Essentially, this would be a popular intervention that would also push back the need to confront the problem of floods by several decades. Indeed, the problems of reservoir sedimentation would have to be confronted by authorities at least two generations hence. The alternative would be much more difficult and possibly thankless, which would be to make the modern-day inhabitants of Bihar understand that floods are a natural phenomenon in the land that their forefathers populated. Undeniably, the monsoon floods are the reason for the fertility of Bihar, and 'living with the flood' is a phenomenon that is an aggravation for but a few weeks every year. The reality, though, is that the politicians in Delhi and Patna would find it much more difficult to sell this low-tech, people-centric idea to a politicised voting public than the promise of a high dam and reservoir up in Nepal.

In reality, even though the planned lifespan of the Kosi Barrage project is long over, discussion on alternative solutions has barely begun. The Kosi Breach of August 2008 has forced all to take notice, and even as the humanitarian issues of rescue and rehabilitation continue, it is now necessary to consider solutions for the long term. Intense discussion must begin between scholars, activists, administrators and politicians of both Nepal and Bihar. As far as the flow of the Kosi is concerned, one evidently has to wait out the September-October peak flood season to understand whether the new flow is permanent, or whether the breach can be plugged and the river brought back to its regular Bhimnagar course.

For the long term, there must be reasoned, non-populist and science-based discussion on the alternatives of: a) returning the Kosi to confinement within the existing embankments; b) distributing the flow among several channels in the plains; c) creating a southward tunnel diversion in Nepal so that at least some of the Kosi's western tributary flow descends directly to the plains; d) building a high dam and reservoir above Chatara; or, e) going back to the historical experience of living with the flood in the plains, and adjusting livelihoods and infrastructure to the annual inundation. A discussion is needed to arrive at the most humanitarian, equity-driven, practical, ecologically sound and long-lasting solution. The Kosi has reminded us that there can be no more shirking.

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