The subject of this diploma thesis is strength analysis of the gully in the hydropower plant. At the beginning of the thesis is the division of water structures, from the point of view of use, according to the construction, technological parts of dams. The following is a section with a description of the inlet closure, how it works, of which it is made. Further strength calculation of beams in the inlet closures. Then the inlet closure is calculated in the ANSYS program, where the static strength deformation analysis and fatigue are solved. Based on the results, the result is evaluated by the strength analysis and compared with the original calculation.