Flood Risks and Reduction Approaches in Bangladesh

Abstract

Bangladesh is one of the most flood prone areas of the world because of its unique geographical setting and physiographic features together with a massive and unique hydraulic system. The ever increasing population, ill-planned infrastructural development and massive flood control interventions in a floodplain environment have resulted in flood disasters becoming larger and more frequent in recent times. Socio-economic impact of floods is profound; the flood prone zones represent areas with the highest incidence of the extreme poor, and the number of poor living in high flood risk areas is on the rise. The damage to infrastructure constitutes the major proportion when it comes down to economic damage resulting from floods. Since mid 1960s there has been a steady growth of flood control and drainage projects in Bangladesh through the construction of embankments, drainage channels, and sluices and regulators, with the total coverage area standing at 5.37 million ha. While the projects yielded a number of positive impacts such as increase in agricultural production, increase in economic activities, and reduction of damage to infrastructure inside protected area, the projects in general could not attain the desired objectives because of lack of consideration of interdependence of land, water, ecosystems and socio-economic development. Projects were mostly formulated with single objectives, aiming to solve the immediate problems without giving adequate attention to potential, undesirable long-term consequences. Ill-planned growth of projects have impacted the hydraulic stability of the system, with projects being able to provide protection against normal floods, while largely failing to provide protection during moderate to extreme floods. The cost of environmental degradation has been rather very high. Storage functions of floodplains have been lost, impacting important hydrologic functions of floodplains such as moderation of flood peaks, augmentation of dry season river flows and replenishment of groundwater storage. There has been substantial damage to capture fisheries because of disruption of hydraulic connection between river and floodplain. Disruption of links between river and floodplain by embankments has impacted country boat transports. Livelihood activities of different groups, especially the marginalized, have thus been compromised. In the light of the experiences with the flood control projects, the necessity to harness the beneficial impacts of floods especially in maintaining soil fertility and sustaining fisheries resources has become apparent. All the socio-economic and environmental concerns of earlier practices gave rise to exploration of alternative management strategies which are more resilient and environment friendly. This chapter provides a review of risks associated with different types of floods in Bangladesh. It also gives an account of historic floods and their impacts. Flood risk reduction approaches undertaken in Bangladesh and their impacts and consequences are discussed at length. The chapter also discusses three innovative flood risk reduction approaches that have evolved in Bangladesh, which tend to address the socio-economic and environmental concerns of typical flood control measures.