Rivers have been losing its self-cleaning and holding function in the past, because of radical interventions to water and waterside areas, biotic diversity and the number of habitats decreased and morphological and hydrological characteristics of watercourses have also changed. Thirty-six kilometers long river Mislinja that springs under Rogla runs through Mislinja and Slovenj Gradec and flows into river Meža at Dravograd is no exception. In the thesis is presented the hydraulic analysis of Mislinja section between settlement Dovže and Slovenj Gradec and natural measures that would improve waterside condition and connection of people with the river are proposed. Hydraulic and ecological needs were taken into consideration. For topographical data preparation ArcGIS was used and its expansion HEC-GeoRAS for watercourse data entry (river canal, river lines, riverbanks and cross profile course). Hydraulic analysis for existing and new condition of different currents was made with program HEC-RAS and a prepared hydraulic model.