Modelling is a tool used to simulate the performance of any type of WWTP (wastewater treatment plant) which empowers the user to optimize the response of works by changing influent loads and operational conditions with minimum effort and low cost. STOAT (sewage treatment operational analysis over time) software is used to simulate the performance of wastewater treatment plants dynamically. In this paper, a model was built by STOAT software for the Hannoville WWTP allowing to analyze and study the enquiries in a shorter period of time associated with laboratory analysis. Additionally, the model can be used to estimate the response of the system to a diversity of problems. The hydraulic shock load was tested for the entire WWTP consequently allowing the application of strategies that guarantee a better performance by presenting the analysis for the entire plant. Through the aid of STOAT software, a model was built for the whole plant with daily sewage volume entering the treatment plant in a year. The study showed whether the plant can accept a higher flow than that it regularly receives or not. This proved to be successful and the plant has the possibility to accept double the hydraulic shock load, meanwhile, the variations of resulting data were acceptable when compared to the Egyptian environmental requirements.