This graduation thesis briefly describes the beginnings of hydro power generation and needs for hydropower production. Although in literature exist many classification of hydropower, in this thesis are listed the most commonly mentioned classificaton and it is described a normal hydro power plant. Further in the text has been described the term "water turbines" and their types, and influences on different types of water turbines. Apart from the influence on water turbines, in the text is described the influence of generators and pressure regulators. It is presented the physical model of the pressure wave at the closing of the latch and it is described the stopping of the water flow at the end of the pressure water which leads to a water strike. At the end of this graduate thesis is introduced the work of a small hydro power plant located on the river Krupa