The authors propose a “rural hydrology" approach for investigating and planning of rural infrastructure build-up in the floodplain zone of Bangladesh. The rural hydrology approach, a form of “alternative engineering", requires the following minimal set of items; a motorcycle or bicycle, feet to walk around, an eye to see the real environmental conditions, an ear to listen to those who are informed of the local conditions, and a flexible mind to share with local people, in order to identify land and water conditions, constraints to development, and the real needs of the locality and local people. Here, a case study is documented. The dynamic hydrological environment of the Tangail district floodplain was analyzed at the level of the union and the results were proposed to be applied to formulate plans for building rural infrastructures. Based on the rural hydrological viewpoint, it is possible to understand a correct dynamic hydrology of the union level. It should be possible to make plans for soil mounded feeder roads, culverts and bridges, which do not disturb the hydrological balance and stability of crop production, using only reasonable labor instead of a great deal of labor and investment. “Rural hydrology" can be a practical proposition for rural development in less developed countries.