Among the various types of renewable energy sources, generating electricity using the watercourses of mountain rivers and streams through small and micro hydroelectric power plants is a promising approach. This method effectively addresses the electricity deficit. The research aims to develop an effective design of an autonomous float-type bi-rotor micro hydroelectric power station installed on watercourses with a natural course. The paper presents the results of research conducted by the authors on several fronts: patent analysis, the current status of similar micro hydropower plant designs, and the development of a new bi-rotor micro hydropower plant with a water intake reservoir. It also includes theoretical studies to verify the interaction of water flow with the impeller blades. Additionally, the research findings on identifying a suitable generator for the varied bi-rotor micro hydropower plant design are discussed. Based on the research and calculations, the authors concluded that the proposed design of a floating-type bi-rotor micro hydroelectric station with a water intake tank offers several advantages. Mounting the water intake tank on the impeller blade of the hydro turbine increases power, reliability, and efficiency. Additionally, the turbine unit design is simplified; the system’s weight and overall dimensions are reduced.