The diploma thesis focuses on testing the impact of building the non-level full access road of the main road Škofljica - Šmarje regarding the hydraulic condition in this area. It had to be tested if building the access road caused conditions to worsen and give a solution to eliminate the impact. The calculation was made for flood waves of a few different hourly downpours with return periods of 10, 100 and 500 years. With this calculation, the critical flood wave was determined, and flood risk maps and maps of flood risk classes for the current and planned status were drawn. The downstream impact of the planned measures directly under the drain field Rupe was also tested. This calculation was performed using the software tool HEC-RAS. The impact in the area of Škofljica was tested with a two-dimensional calculation of the surfaces with the software tool MIKE FLOOD of the Danish Hydraulic Institute.