India - Bihar's curse;embankments

The floods in Bihar this year, described by some as the worst in 50 years and others as the worst in history, have been horrific in their destruction. The point is that north Bihar is visited by floods every year and routinely devastated by its river systems, led by the Kosi, which originate in Nepal and eventually flow into the Gangetic plains.
To contain the Kosi, India and Nepal in the late fifties built the Koshi dam in Nepal and India began to build a system of embankments along the flow of the river. India is supposed to take care of the dam and the embankments but the political uncertainty in Nepal and the administrative culture in Bihar have led to poor maintenance of the dam and the embankments in Nepal. This year the breach has taken place in Nepal itself, affecting people on both sides of the border.
The predictable tendency in India, which bears the brunt of the devastation though Nepal also suffers, is to blame Nepal for not co-operating with India. In the same breath it is suggested that the solution lies in building more and bigger dams in Nepal to contain all the excess water. How that can happen when Nepal is not co-operating is unclear. Also bigger dams mean more inundation and why Nepal should want that is equally unclear. Nepal may stand to earn huge sums by selling hydro power to India generated by new dams but the downside of those — inundation, local protest, quick silting of reservoirs — is well known.
It should by now be clear that the obvious culprit which is leading to bigger and bigger damages in Bihar is the medicine itself — the embankments. Those with a vested interest in them — politicians, civil engineers, contractors — will be loath to agree to this but the mystery is why the rest of us have not caught on.
Three years ago Eklavya Prasad, an expert on the subject, pointed out in Civil Society that the flood-prone area of Bihar had nearly tripled from 2.5 million hectares in 1952, when there was only 160 km of embankment, to 6.9 million hectares in 2002, when there was 3,430 km of embankment. Today, three-quarters of the population of northern Bihar are at risk from floods every year during the monsoon.
Dinesh Kumar Mishra, an IIT engineer who is a mine of information on floods, told the same publication: “Constant breaching of embankments is an indication of the river’s disapproval of human interference with its natural flow. The natural process needs to be understood by those implementing lopsided flood control measures.” Earlier people developed local flood control measures to cope with nature. Muddy flood water spread over large areas formed deltas, deposited layers of rich soil, brought soil moisture and recharged groundwater. In return for such bonanza, “people happily persevered with the seasonal inconvenience of floods.” The embankments have created a disaster. The need of the hour is to “reverse the process and create an environment where people benefit out of natural floods.”
The regular routine is that more and higher embankments (silting is causing the river bed to rise, at times taking it above the level of the surrounding land) are getting built even as they are being breached by the monsoon fury of the waters every year. Once such water gets out it inundates low-lying areas beyond the embankments. These don’t let the water go back to the river channel once the flow decreases. This is creating havoc through floods that last longer, large tracts get waterlogged and become uncultivable because of the sand deposited by the water.
Villagers who are displaced by the floods camp on the embankments for months, often have nowhere to go back to, and keep demanding relief and alternative sites to rebuild their lives. The corruption and inefficiency of the system means little relief. The long- term trend is that soil fertility is being reduced and more and more sandy soil is inducing farmers to go in for maize and wheat instead of the traditional paddy. Says one observer, north Bihar is slowly becoming Rajasthan.
Mishra’s logic of living with floods is reflected in a modern scientific study by two engineers, G Venkata Bapalu of ESRI India, the global firm which develops geographical information system (GIS) software, and Rajiv Sinha, faculty in the civil engineering department of IIT, Kanpur, in which they have used GIS in mapping flood hazard in the Kosi basin and computing a composite index for measuring flood hazard.
They say, “To check the lateral movement of the river as well as for flood control, embankments on both sides of the river were constructed. Although this has confined the lateral shift of the river within the embankments, the problem of … river flooding is getting more and more acute due to human intervention in the flood plain at an ever increasing scale. There must be a realisation that minimizing the risk and damage from floods may be a more rational way of flood management rather than formulating structural measures along dynamic rivers such as the Kosi.”
The validation for their exercise comes from the fact that the flood hazard map obtained by overlaying various thematic layers generated through GIS compares well with the inundation map obtained separately. “Not only do the inundation areas coincide in the final flood hazard map, the severity of the hazard areas is also reflected.”
They prescribe: regulate flood hazard areas, enforce flood hazard zoning. Don’t build embankments, bridges, culverts and houses as if there is no flood tomorrow.