A physical model study was conducted for designing the intake/outfall combination to comply with the Egyptian environmental laws. Based on the dominant flow patterns, and temperature measurements, two alternatives were examined. The first alternative of outfall structure consists of surface open channel. The output of this design did not comply with the environmental laws and has negative impacts on the water quality and ecological life. It was proposed to widen the outfall with 24 nozzles (multi port diffuser) arranged in two rows and separate the outfall into many jets. This new alternative for the outfall hydraulic design succeeded to improve the mixing process and complies with the Egyptian environmental laws.