The aim of this master thesis is hydraulic design of the fish pass for the planned Water structure Kolárovo at the Váh River. The basis of the work is a summary of knowledge about fish passes and their analysis. The work is describing the planned Water structure Kolárovo, its specifications and parameters. Ichthyofauna of the area of interest belongs to upper bream fish zone. The design process the information from methodology of the Ministry of Environment from the year 2015. Suitable fish passes are technical slot pass, bristle fish pass and nature close type of fish pass - bypass channel. This work contains 8 design variants. The suitability of the designs was assessed in the software HEC-RAS and River2D.