The introduction of this final work refers to the basic theme of the work and gives basic information about hydro power plants, their classifications, the reasons and the importance of their use. After introduction, work talks about small hydro power plants in general. It gives a description of the work principle of small hydro power plants, their performance, their main characteristics, their advantages and disadvantages in relation to large hydroelectric power plants. The main characteristics of small hydroelectric power plants were also given. In the practical part of the work, a small hydro power plant „Zelena“ was used as an example. In this part a complete conceptual design of the project was described. Within the conceptual project, calculations related to the forecasting of the flow through the river bed and a description of the hydraulic model simulation of the small hydro power plant were given. Also, it is presented the mechanical and electrical part of the project and a comparison of the investment costs of the small hydro power plant compared with the major hydroelectric power plants. The last chapter describes the impact of small hydro power plants on the system.It describes the connection of the small hydro power plant „Zelena“ to the distribution network and showes the power unit's network operation capabilities.