Hydropower plants benefit from the power of moving water to generate electricity, offering a reliable and renewable source of energy. With the increasing demand for clean energy and the need to reduce gas emissions, hydropower plants have gained significant attention in recent years. This paper provides an overview of small hydropower plants, including their design, operation, and speed control system, as well as their performance characteristics and environmental benefits. We also discuss the challenges and opportunities for the development of hydropower plants and their role in the transition toward a sustainable energy system.