Within the framework of constructing mega coastal ports in Egypt, this research originated to achieve coastal management sustainability in its surroundings by modelling the Longshore Sediment Transport “LST”. Principally, literature in the fields of modeling and sediment transport was reviewed and scrutinized. The model was calibrated by contrasting the calculated wave data against 2003 measured data at Damietta Buoy. The model inputs were tuned to produce a result that was similar to the observed data. Moreover, the model results were validated against 2005 measured data at Damietta Buoy. Likewise, MIKE21 SM was used to estimate 2011 bed levels within Damietta Port, where 2010 bathymetrical survey data were utilized. Confident with the model results, it was employed to synthesize transport data of 1940-2020, in terms of LST, Gross LST “GLST” and Net LST “NLST” while considering human intervention and implementing ERA5 wave data. Results were obtained and analyzed, and there was a significant correlation between the significant wave height “Hs” and the wave period “Tp” and GLST (i.e. R=0.91-0.79, respectively). The analyzed trend results highlighted that pre-construction phase of Damietta Port, increases in GLST and NLST were modest (1139.9 and 243.7 m³/yr, respectively). However, in post-construction phase of Damietta Port, they escalated between 4679.47 and 3962 m³/year, respectively. The analyzed results indicated that after introducing coastal protection, GLST and NLST were trend reduced to 2978.1 and 2176 m³/year, respectively.