This study presents the hydrodynamic flushing modeling of the new extension marina at Al-Wakrah Port, Qatar. The planning of the extension must be carefully designed to guarantee the adequate circulation of clean water. So, water flushing problem concerns must be assessed. A 2D numerical model was utilized to simulate water circulation in the port under the natural forces of tide and wind. The model should assure that the extension plan of the port would not result in the development of stagnant water areas, besides ensuring efficient water exchange throughout the entire water system. Based on a flexible mesh model of the study area, the hydrodynamic and advection/dispersion modules of MIKE 21 have both been used to the investigation. The constructed model was applicable for the analysis of free-surface flows, hydrodynamic forces, and dispersion in the proposed marina layout. The hydrodynamic module used tidal and wind data to generate tidal currents in the marina basin. The results were used as input to run the advection/dispersion module that simulated the spread and movement of conservative tracer material. After 30 hours, the tracer concentration approaches 10% of its initial concentration. This indicates excellent flushing due to the higher exchange with the Arabian Gulf.