Floods and Environmental Justice in North Bihar: Contextual Vulnerabilities of Historically Marginalised Communities in the Kosi Sub-basin

The Kosi region of North Bihar is one of the largest inland river deltas in the Gangetic River basin. It is also home to millions of people dependent on agriculture and fishing. These communities cultivate Kosi’s rich fertile alluvial soils. Nonetheless, due to the unique geography of the river, it is highly susceptible to flooding. Originating from the lofty peaks of the geologically young Himalayas, the river naturally disperses its waters across the floodplains of North Bihar, India.

During the colonial era, efforts were made to control flooding by constructing earthen embankments along the Kosi River and its tributaries. This practice of embankment construction has persisted under the supervision of governmental line departments at both the central and state levels. While these embankments were intended to be life-saving measures, they have instead worsened the frequency and severity of floods. In the aftermath of embankment construction, floods have devastated crops, livestock, and the lives of communities. Countless individuals have been displaced, and a permanent division has arisen between those living inside and outside the embankments. While a select few communities have benefited from embankments, numerous others have experienced heightened flood risks and impaired livelihoods.

In my study, I adopt an environmental justice and contextual vulnerability framework to comprehend the unequal distribution of flood risks and vulnerabilities faced by two marginalized communities: the Musahars and Mallahs. These communities reside precariously in the Kosi floodplains of North Bihar. I investigate the changes in the region's natural features, including the flood patterns, frequency, and intensity resulting from the presence of embankments. Furthermore, I explore the impact of these changes on the Musahars' agricultural practices and the Mallahs' fishing activities in the districts of Darbhanga and Saharsa.

To achieve a comprehensive understanding, my research employs an interdisciplinary approach by analysing both the biophysical factors and socio-institutional causes of the escalating flood events at the household level in the region's villages. Additionally, I examine the trends in precipitation within the Kosi sub-basin and their influence on flooding incidents. Through an analysis of historical precipitation data and river morphology in the area, I aim to assess their role in the increased frequency of floods. To grasp the transformations in the communities' lives during the post-embankment period, I have designed and conducted qualitative and quantitative methods, including semi-structured household interviews, focus group discussions, and oral history interviews.

The analysis of the biophysical aspects and precipitation trends in the Kosi sub-basin indicates that changes in precipitation patterns alone cannot be held solely responsible for the escalating frequency, intensity, and magnitude of floods. These hazards are a result of various factors, including alterations in river morphology following embankment construction and contextual socio-economic drivers. Moreover, the analysis of household data suggests that both within and outside the embankments, the frequency and intensity of floods have increased in the post-embankment period. The embankments have played a significant role in exacerbating flooding and creating an unequal distribution of flood risk among the communities residing along the Kosi. However, the extent of flood risk varies depending on various contextual factors, such as the geographical location, caste, class, and gender of the households.