Community water management to intensify agricultural productivity in the polders of the coastal zone of Bangladesh

Most of the lands of the southern coastal zone of Bangladesh are protected from tidal flooding and storm surges by embankments constructed during the 1960s and 1970s, creating polders. Sluice gates in the embankments connect the canals (former river distributaries) inside the polders to the surrounding rivers, providing the opportunity for water intake from, or drainage to the rivers by judicious management of the gates. Yet, unlike northern and central Bangladesh, the polders have not benefited from the genetic breakthroughs which underpinned the Green Revolution during the 1960s. Flooding during the wet season followed by severe drought and high levels of salinity during the dry season plague the coastal zone, limiting the application of improved technologies that increase agricultural productivity (amount of harvestable produce per unit of land). While the potential of these technologies has been clearly demonstrated, the lack of an integrated landscape approach to water and crop management precludes agricultural intensification in the polders. Therefore, the ability of community-led water management and land-use planning at the watershed level was tested to improve agricultural productivity in a polder in southwest Bangladesh during 2015–2017. Engaging with communities to employ more pragmatic land-use planning (based on topography/hydrology) and scheduling of sluice gate operations has shown the potential to intensify and diversify cropping systems in the polders, and increasing production by twofold to threefold. This was achieved using improved rice varieties and non-rice crops in wet and dry seasons, respectively, enabled by strategic management of the sluice gates to drain the lands as needed during the wet season and to facilitate timely establishment of non-rice crops after rice harvest. The community-based water management approach has been the key entry point for making inroads toward transforming the agricultural production systems in the polders.