Nearly two billion peoples in developing countries do not have access to electricity service. Renewable energy resources are a best option for rural electrification in a country like Ethiopia where electric light is a luxury enjoyed only by a few peoples. Nowadays, only around fifteen percent of the populations living in urban and semi urban areas are connected to the national grid. The remaining populations are living in scattered rural villages and have very remote chances to get electricity from the grid. The only realistic approach to electrify the rural areas seems therefore to be the off grid or selfcontained system. The contributions of renewable sources of energy like micro/mini or Pico hydro power, to rural electrification are minimal still. The main objective of the present study was to identify the potential of mini hydropower site and proposing a plant for rural electrification in Keber River around Tobacha kebele. So in the research the study starts from the estimation of the design discharge by analyzing of the stream flow using the flow duration curve. For estimating the design discharge the available discharge in the river, the population demand and some guidelines for development of mini hydropower were used. So using the above constraints the power of 120kw was designed for a 300 households, 1 clinic and 2 elementary schools. Besides estimating the power, the present study focuses on design of civil structures and selection of electromechanical components. Generally the result of the study shows that construction of mini hydropower was feasible in the project site.