The mouth of the drain-reach (DR), Egypt, discharges the wastewater of the El-Umum Drain and excess water from Mariout Lake into the Mediterranean Sea through El-Max Pump Stations (MPSs). During a strong downpour in November 2015, the pumped water returned to the MPS building. A hydraulic simulation modeling was created to ascertain why this occurred, provide remedies in January and October 2016, and assess the actual implemented measures in July 2021. The investigation found that the DR was shallow, narrow, and had numerous restrictions; it was advised that these limits be lifted.  Even though the dredging and bed widening did not go exactly as planned, the final water sections can transfer a maximum flow of 185 m³/sec less than intended. Reopening the Old El-Max Pump Station by 74 m³/sec capacity is recommended as a long-term alternative to supplement the MPSs during anticipated critical conditions