The diploma thesis deals with the design of nature close to the flood protection of the city Prostějov at the confluence of the watercourses Romže and Hloučely and the flow Valova (Romže). In canculations there was solved capacity of individual sections and canculation of levels for one-year, five-year and twenty-year flow. For canculations there was used one-dimensional mathematical model HEC-RAS 5.0.3. Determination of roughness of bottom and slopes was based on personal visit. The result of this diploma thesis is evaluation of current state and proposal of a nature close to the flood protection in the individual streams in the city Prostějov. The thesis contains the calculation part and the drawing part documenting the proposed measure