Research, optimization and practical implementation of a Small Hydropower Plants as a source of clean electricity are one of the actual tasks in the current energetics, which is virtually impossible to solve without powerful computer support due to the strongly nonlinear nature of such systems. The article presents an overview of the most common simulation model schemes of Small Hydropower Plants, whereas explores the sub models of its individual subsystems. The most important subsystem and a so-called heart of the hydropower plant is the hydraulic turbine, which efficiency calculation is analytically demanding and dependent on parameters that are often obtained only by a theoretical estimation. In this article, a fuzzy system was used to create its model based on a measured operating data of the turbine flow rate and the height of its water column without any need of knowing exactly the turbine parameters. Such a model is applicable in practice, e.g. in the designing process of an energy-optimized hydro-turbine control, as well as for the effective determination of the deterioration rate. The correctness of the results was verified by simulation measurements in the MATLAB software.