Aim of the study: Flood conveyance analysis of the Hydrosystem of the Wrocław City. Material and methods: Use of the hydrodynamic numerical model MIKE21. Use of the measurement data of the historic floods. Results and conclusions: Both the flow partitioning among the system channels, water levels and flow velocities were depicted and analyzed to bring a clear picture of the system conveyance capacity as well as to bring the effect of modernization into light. In addition, the peak discharge for a catastrophic flood of 1997 has been evaluated.