Floods are common in Bangladesh, where floodplains constitute about four-fifths of the landmass. The floodplains are formed by sedimentary deposits that are carried by three of the largest rivers of the world, viz., the Ganges, the Brahmaputra and the Meghna (GBM) and their numerous tributaries and distributaries. The
country is situated at the end of the catchment area of the GBM river systems, occupying only about 7.5 percent of the combined catchment area. Since this small fraction of the catchment area has to manage drainage of over 92 percent of the water volume, over 80 percent of it being discharged in about five months
period during the monsoon, floods frequently hit and cause havoc in the deltaic plains. Impediments to drainage caused by both natural and man-made factors decelerate the recession of floodwaters, thereby prolonging the duration of floods. Every year, Bangladesh’s low-lying areas get inundated by seasonal floods. From time immemorial, people living in the delta have been experiencing barsha and have adapted to such annual events over the centuries and found ways to take advantage of it.