Demand of energy is ever increasing, especially in developing countries. Renewable energy such as hydropower has become one of the most demanded sources of energy for its clean generation. Low head hydropower plant is demanded in area which cannot see grid extension due to difficult geographical terrain and other reasons. Gravitational water vortex power plant is one of such low head turbine in which the mechanical energy of free surface flowing water is converted to kinetic energy by tangentially passing the water to a basin, which forms a water vortex. This study is the analysis of different basin structures which has ability to form a gravitational vortex stream from low head, low flow water streams with the optimum runner position in the basin to maximize the output power. The analysis was first carried out by development of the model using CAD software, SolidWorks and it was simulated in commercial CFD code ANSYS Fluent for the measurement of velocity. Secondly, the result so obtained was experimentally verified by measuring the output power.