In years that the Kosi river floods in Bihar, government officials from Delhi and Patna rush to observe the river’s “wrath” from high-flying helicopters. Inevitably, political leaders, bureaucrats and sections of the media delude the Indian public by blaming Nepal for releasing water.

Then, they announce that they have the answer to save the people: the Saptakosi High Dam, to be built in Nepal, and its deep reservoir, which will end the flooding forever. The geopolitical pressure from Patna and New Delhi will be such that Kathmandu’s rulers will find it difficult to resist the pressure.

But as the first part of this series explained, the answer is nowhere as simple. The floods are the result of the ill-conceived Kosi embankment project completed in 1959, which has dramatically raised the height of the riverbed by trapping silt within the confines of the eastern and western levees.

The monsoon passes, the waters recede, media attention shifts, but the silt keeps accumulating, and the Kosi riverbed keeps rising. But before long, the Kosi will break out massively, and there will be pralaya, the only equivalent of which can be the 2004 tsunami and its swamping of populated coastlines around the Indian Ocean.

The high dam idea has not been universally accepted, including in India. As the magazine Down to Earth noted in 2015, “The idea of a big dam has been junked earlier. It reappears every time the Kosi floods.” But it is clear that a massive embankment breakout by the Kosi would take us past the point of no return, and head-over-heels towards the high dam project. The process of design, engineering, bidding, contracts would begin, with the people in Nepal’s valleys and Bihar’s plains denied their say.

The embankment mafiosi would be only too happy if the multibillion-dollar high dam project were to be activated. For now, the network of technocrats, politicians and contractors makes money from corruption that involves filling the Kosi sand into sandbags rather bringing impervious mud from afar, as is required, and piling them on the levee flanks. The high dam would take everyone concerned to another level of wealth, and earning for decades on end – every reason to encourage scientists and engineers to toe the line and to silence voices of dissent.

An ill-concieved idea

The idea of the Saptakosi High Dam was first put to paper by AN Khosla, the Chair of India’s Central Water Commission in the early 1950s. A 1981 study set the height of the rock fill dam at 269 meters. In 1985, the cost estimate for the project was $3 billion.

The “dead storage” of the reservoir would be 4.1 billion cubic metres, with 8.5 billion cubic metres of effective storage. While it is expected that all this storage capacity would be filled with silt, sand and debris within three decades to five decades, the lifespan of the reservoir would be further reduced by cloudbursts in the Kosi catchment, which would scour the mountainsides and dump of rocks and sediment into the reservoir. (Like sedimentation, cloudbursts are a Himalayan phenomenon not studied adequately, and largely absent from the Western hydro-engineering tomes.)

Thus, on a historical timeline the high dam would be a short-term measure. The same sediment that used to gather across the Kosi inland delta and today settles within the embankments, would soon choke the reservoir and end its flood-prevention rationale. As the Bihar government’s own Tenth Five Year Plan (2002-2007) document conceded, “The Kosi High Dam will trap the bulk of the course and medium silt carried by the river.”


In the summer of 1995, this writer was part of a Nepali journalists’ group that visited Bihar under the aegis of what was known as the “Patna Initiative”, where we met the cream of India’s water bureaucracy. The dozen top officials with whom meetings had been set mostly spoke with blind faith and little information in favour of the Saptakosi High Dam. Those who did not agree spoke to us in whispers.

Rajendra Dahal, an editor who follows the high dam issue closely, was part of the group to Patna. As he reported in Himal magazine at the time: “While the demand for Kosi High rolled off the Bihari tongues as easily as one bites into fresh paan, the questioning Nepali journalists found that these vehement proponents had actually done little homework on the technical aspects of their favorite future project. They were unable to respond to detailed queries on economic feasibility, seismicity, sedimentation and alternatives. It was clear that Bihar’s enthusiastic embrace of the Kosi High Dam was based on political and professional expediency rather than a clear appreciation of all aspects of a project as big and as important.”

Nothing seems to have changed in Patna’s thinking in a quarter century since. India is planning to construct a most profligate white elephant, but there does not exist a politician in Bihar or the larger India who will ask the right questions. The only voice that has been steadfast against the high dam is that of the activists of the Barh Mukti Andolan umbrella group, which understands the folly of the embankments from a scientific and social justice standpoint.

While the narrative set by the dam builders commands the mainstream media, activists and scholars on the ground as well as groups such as South Asia Network on Dams, Rivers and People or SANDRP continue to challenge the Kosi follies – the existing embankments and the planned high dam.

The sediment trap

The primary goal of the high dam is said to be controlling floods that the Kosi visits upon the plains, though the benefits of irrigation, hydropower and inland navigation are also touted. The politicians say they want the high dam as a complete solution to save the population of northeast Bihar from the “wrath of the Kosi”, but, if at all, it will address the flood problem only during their individual lives and political careers.

The high dam proponents prefer not to answer specific questions: a) Is rainfall in Nepal the only cause of flooding in Bihar? b) Do you consider siltation a problem? If so, do you have the technology to desilt the humongous reservoir? c) Have you looked at alternatives to the high dam and reservoir?

Academics who study the Kosi embankments do point to the futility of such structures given the dangerous build-up of sediment. They continuously call for alternatives, but intriguingly almost no one suggests one. They do know that the Saptakosi High Dam will be one gigantic sediment trap, but prefer to leave the question of ‘what else’ hanging because to openly opposing the high dam is akin to challenging the high priests of a fundamentalist religion. To go head-to-head with the Saptakosi High Dam would leave you without friends in Patna, where politics is programmed, like flood water, to seek the easiest way down a decline.

Local fisherfolk find the Kosi Barrage structure useful for carrying out their vocation. Credit: Ajay Upadhyay

As far as Nepal is concerned, the Kathmandu leadership has been alternatively unresponsive and irresponsible on the matter of the Kosi, swinging like a pendulum between Indian pressure and perceived national self-interest. The Kosi Agreement of 1954 conceded extraterritorial jurisdiction to the Bihar government to manage and upkeep the Kosi Barrage and associated infrastructure. It rankles Nepali citizens to see Bihar officials and engineers having the run of the Kosi region and taking key decisions such as the opening of the barrage sluices, levee upkeep, and assignment of contracts.

But then, Kathmandu’s government wants to protect its deniability, to be absolved of responsibility when the “flood blaming” begins. It is able to point out that the entire embankment and barrage infrastructure is controlled by India. Kathmandu’s lack of involvement on the Kosi not only impacts the quality of life and environment on the Nepali side, including the management of the Kosi Tappu Wildlife Reserve, it also makes Nepali authorities less than aware of the disaster-in-making within its part of the Kosi embankments due to the sediment buildup.

Kathmandu’s deliberate disregard also means that it is not able to marshal arguments against the Saptakosi High Dam. Unable to challenge the Indian politicians and bureaucrats as they come on strong, the attitude of Kathmandu’s rulers since decades has been to sign the high dam papers and agreements while hoping that the project will not proceed. It is also true that there have been many in Nepal’s hydrocracy who enthusiastically support the high dam.

Quality of democracy

To begin with, the floods in the Bihar inland delta do not emanate only from the Kosi catchment area above Chatara, i.e. the hills and mountains of Nepal and Tibet. There are also the rivers Marin, Bagmati, Kamala, Ratu, Khando, Adhwara and Balan that deliver water separately into this part of the state. Each of these rivers have been saddled with embankments, and in many parts the stagnant waters remain outside the levees throughout the year. As the engineer and water scientist Ajaya Dixit notes, “The flood waters are not allowed to flush out. They have created quite and unmanageable hydrological mess.”

As for the sediment buildup within the reservoir, let the stark truth be told – that the high dam builders do not have the knowhow to desilt a mountain reservoir. The science and engineering just do not exist. Silt that had the freedom to naturally spread out over the 100-km wide Kosi fan has been constricted between an average 10-km between the embankments, since 1959. The high dam would constrict all this sediment into the narrow gorge above Barahachhetra.

The would-be dam builders have no concern for Nepal’s mid-hills that would be swamped by the reservoir, whereas the very physical profile and map of the country would transform if the massive reservoir were to inundate the three river valleys that meet at Tribeni. Traditionally, the pahad (mid-hill) people of Nepal have prized the besi (valley floor) for paddy cultivation, transport and commerce.

The reservoir would directly displace 75,000 people and inundate a total area of 196 sq km, of which 51 sq km would be khet – irrigated paddies.

It is worth pondering how Nepal’s newly federated polity is going to take to the proposed inundation of a good part of its territory. As a Kathmandu-centric country, till 2015, it might have been relatively easy for Nepal’s rulers to sign off on the high dam and the associated swamping. But the new Constitution of 2015 has brought much of the Kosi region under Province No. 1 and the creation of empowered provincial and local government units has transformed the nature of representational politics.

This paradigm shift in governance north of the international border may come as a surprise to the technocrats and water barons of India, who have exhibited great lack of caring for socio-political ground realities in Nepal.

Villagers in Nepal on a highway washed out by a flood in the Kosi river. in August 2008. Credit: Reuters

How ironic that India’s hydrocracy speak so easily of high dams and reservoirs when their “age” is over, particularly in those parts of the world where people’s voices tend to be heard. In essence, the push for the Saptakosi High Dam is also a litmus test on the quality of democracy in India (and Nepal, for that matter), and the ability of the impacted people to be heard through the cacophony of money, careerism, certitude and bombastic populism. While India may be described as the world’s largest democracy, the quality of that democracy must be questioned when the voice of communities is muzzled and local government easily ignored.

Dipak Gyawali, firebrand academic and Nepal’s former Minister for Water Resources, is convinced that the Kosi embankments as well as the Farakka Barrage downstream on the Ganga have ensured the impoverishment of the people of Bihar. “The politico-bureaucrat-contractor iron triangle have done nothing but increased human misery, by denying the spread of the Kosi silt which has been a blessing through the ages, and ensuring that waterlogging converts valuable land into a jalkumbhi [water hyacinth] wasteland,” he said.

Gyawali added: “The embankments are not challenged because that would mean upturning the very political-economy of Bihari politics. It would require a revolution of Jai Prakash Narayan proportions to take on this entrenched system.”

The issue of Himalayan seismicity that roiled the debate over the Tehri Dam for so many decades applies even more to the Saptakosi High Dam, given the added height of the rockfill dam, the volume of impoundment proposed, and the inevitability of a Richter 8+ tremor over the course of the coming century in a region that saw the Great Bihar Earthquake as recently as 1934.

Reservoir-induced seismicity is not even discussed by the high dam planners. The matter of massive Himalayan cloudbursts – such as seen in eastern Uttarakhand in 2013 – and how this may endanger both the present embankments and the future reservoir and high dam does not find mention even in scholarly papers.

Further, should not the Indian policy makers are so neglectful of the drowning the upstream valleys of Nepal be contemplating the drowning of millions downstream through possible high dam failure? This is not a matter that can be simply brushed off for being “improbable”.

Given the natural rate of sedimentation, the proposed reservoir will choke into redundancy within 30 to 50 years, which is why we must demand the high dam builders to have a worldview that is longer than a politician’s career span. And the engineers must show how they will de-silt the reservoir before they take the planning one step further.

Head in the Kosi sand

The leadership and society of Nepal’s Province No. 1, various local governments involved as well as civil society must urge Kathmandu government to ask questions rather than sign meekly what New Delhi places before it. The civil society and leadership of the plains-based Province No. 2, with Janakpur as its headquarters, should do the same as they too will be impacted by decisions taken with regard to the Kosi. If New Delhi and Patna are not bothered about the floodplain people, Kathmandu should be, but as of now it is seen to be equally complicit.

There is further engineering illogic: if flood-relief is the main reason for the high dam, it would make sense to keep the reservoir empty through the autumn, winter and spring, so that you have a cushion for the monsoon rush. This means that the projected benefits of hydropower, navigation, urban use and irrigation would not accrue with the Saptakosi High Dam. Meanwhile, a reservoir kept full for all these uses would make no contribution to flood control.

According to SANDRP, even Indian government reports show that “the highest proposed high dam” would silt up in less than four decades, what with 90 million cubic meters of sediment being trapped every year behind the high dam. In a 2008 press release titled ‘Kosi High Dam will only bring great disasters’, and aimed at both the Indian and Nepali public, the group warned of the unmanageable cost of the Saptakosi High Dam – set at (Indian) Rs 40,000 crore at the time, but cost escalations are bound to take you past the Rs 50,000 crore mark over the minimum two decades required to complete the project.

What we have, on the one side, is the relentless and lethal rise of the Kosi riverbed that must be understood in other than real time, and the annual shoring up of the embankments. On the other side, is the obvious folly and unworkability of the Saptakosi High Dam that is presented as the only panacea. Between these two extremes, the policy-makers in Patna, Delhi and Kathmandu must lift their head up from the Kosi sand and address the alternatives.

Kanak Mani Dixit is a writer and journalist, and founding editor of the magazine Himal Southasian.

This is the first of a three-part series on the Kosi river disequilibrium. Read the series here.