The British had in 1855 embanked the river Damodar in Bengal as an experiment in flood control. They were to regret the consequences. In the following years, the flood levels rose and the water breathed the embankments at many points. Compounding matters, the embankments impeded the natural drainage channels of rainwater, leading to extensive waterlogging that both reduced the arable and abetted epidemics. This experience was sufficient to dissuade the British from embanking other flood-prone rivers. But what restrained the colonial government was not enough to curb those who followed. Embankments returned with a vengeance in the political and engineering arenas after the colonialists departed in the mid- 20th century . The Kosi river was one of the first to be straitjacketed within embankments, and those living in its vicinity were eventually to suffer the consequences. The process that gave rise to the embankments is as instructive as its outcome is poignant in a South Asia where politicians and government engineers continue to put up embankments as the quick and easy fix .
Silted Kosi
The Kosi is a lively and turbulent river of north Bihar that originates in the Tibetan highlands. It penetrates the Himalayan barrier between Kanchendzanga and Mt. Everest and descends from the mid-hills near Chatra in Nepal and joins the Ganga near Kursela in Katihar district of Bihar. The Kosi has a catchment area of about 59,000 sq-km above Triveni in Nepal, where three of its major streams converge to give it the name Kosi. In the plains, the river has changed its course many times and in the past 200 years alone, it shifted from Purnea to Saharsa, a distance of about 160 kilometres. Its length in the plains is 307 km, of which 254 km is in Bihar. The river carries a large sediment load in its flow, whose accumulation on the bed causes it to meander.
The shifting course of the river and its perennial tendency to flood posed a serious challenge to engineers attempting to control its flow. But the experience of past follies in the Damodar and elsewhere, did not restrain the independent Indian state from embarking on a grandiose plan to tame the Kosi in the 1950s by confining its flow within embankments.
The idea of embankments as a solution to the Kosi floods had been proposed even before Independence. In 1941, the Congress leader from Bihar, Anugrah Narain Singh, advocated a relocation of the population of the Kosi belt to the hilly areas of Ramgarh, in Hazaribagh district. This provoked a fierce debate, and the vehement opposition of those likely to be affected led to the proposal being shelved.