In the master's thesis, we studied the influence of locating the dry detention area along the Mura River in the Gaberje area in the municipality of Lendava, which is exposed to high flood risk. In the HEC-RAS 5.0.5 hydraulic software we concentrated on the area positioned next to the left bank of the Mura River on the section between settlements Kot and Kolonija Petišovci. We prepared a 1D model of the river channel within high-water levees and a 2D model of floodplains on the dry side of the left bank levees. The models were joined in a coupled 1D-2D hydraulic model. For the planned dry detention area, a volume analysis was performed and sizing of the lateral structure (weir) was conducted in order to control the inflow of water into the detention area during the floods. In the area of the inflow into the dry detention area, a connection with the lateral structure was modeled over the high-water levees. Based on the results of the hydraulic model, we demonstrated the process of dimensioning the lateral weir with a stilling basin. We analyzed the influence of the dry detention area operation on the outflow hydrograph shape and considered lowering of flood water levels along the studied section. Results of our calculations show that the impact of the dry detention area has a beneficial effect on lowering the peak of a high-water hydrograph with a 100-years return period and a duration of four days, since the water levels along the high-water embankments of the studied area decreased on average by approximately 25 cm, in certain places up to about 40 cm. We estimated that 6% of the total volume of a high-water wave (16.78 million m3) could be accumulated in the dry detention area, the maximum size of the flooded detention area would be 661 ha.