The new government of Bangladesh is faced with enormous problems of mobilizing a growing population and of allocating resources to achieve lasting and equitable improvements in social welfare. Land now occupied by tanks is currently neglected by economic planners; we argue that a tank development scheme accompanied by land reforms and establishment of marketing cooperatives can complement other land and water development programs and contribute to productivity increases with favourable distributional, nutritional, and ecological properties. In general, it will be maintained that the approach used to evaluate the potential of the tanks of Bangladesh, an approach based upon a view of their role as components in a system of economic, sociological, and ecologic relations, is essential to the further development of technological alternatives that can contribute to equitable, self-sustaining social development.