The following work gives the details of the modelling, simulation, and testing of a small portable gravitational water vortex (GWV) based power plant. The gravitation water vortex is an ideal source of renewable energy for rural areas that have a small body of flowing water. For this purpose, we have selected a small size for the vortex chamber that enables it to form a vortex with limited amounts of water. The paper gives the details of the simulation of the GWV in COMSOL FEA software and the parameters that were chosen for optimization. These parameters were the height of the vortex chamber, the number of blades, the length of the blades, and the tilt angle of the blades. These parameters were systematically varied step by step, to observe their effect on the speed of the rotor. The results of the parametric sweep that was performed on all the parameters are also presented. Based on the simulation results an optimal set of parameters was chosen for the physical implementation of the GWV. The paper also goes into the details of the construction of the physical GWV, the experimental setup that was devised for the testing and verification of the simulation results.