The purpose of the Musaimeer Pump Station and Outfall (MPSO) project is to receive storm water runoff and groundwater flows from the Abu Hamour Tunnel and to provide a pumping station, a 10 km marine outfall tunnel and a diffuser field to dispose of the flows into the sea. The project site is located immediately south of the land that was reclaimed for the newly constructed Hamad International Airport (HIA) at the eastern terminus of the Abu Hamour Tunnel which forms a link to allow discharge of storm flows collected in the southern and western parts of the Doha over a total catchment area of approximately 190 km2. Hydraulic Design for MPSO (Musaimeer pumping station and outfall) was implemented for dry weather flow of 1.9m3/sec and wet weather flow of 19.7m3/sec. The system was designed with increased operational redundancy including 2 screen channels, bar screens and grab rakes, each channel being able to handle the maximum design flow, 2 wet wells with grit removal and oil and grease removal system, 10 submersible pumps (9 duty+1 standby), outfall chamber, drop shaft, 10 km marine outfall tunnel and diffuser field comprising of 6 HDPE pipe branches and 84 non return diffuser ports-duckbill valves. Hydraulic Design calculations were cross verified by CFD modelling, physical modelling in 1:9 scale and surge analysis results concluding on final hydraulic design conclusions and recommendations. Hydraulic Design parameters presented in this paper were verified during operation and maintenance period of the project and will be demonstrated herewith.