The Water Recovery and Management (WRM) system on Space Station Freedom (SSF) is modeled using SINDA '85/FLUINT to determine its hydraulic operation characteristics, and to verify the design flow and pressure drop parameters. The WRM system consists of the Potable Use water, Waste water, and Fuel Cell loops, as well as the Fluid Management System and experiments, which are not included in this model. This system will be the first closed loop water regeneration system used in space flight. The water is driven in each loop by storage tanks pressurized with cabin air, and is routed through the system to the desired destination. The model considers the flow of water from the storage tanks to the use points and back, as determined by each individual flow diagram for the Permanently Manned Configuration (PMC) phase of SSF. The WRM system is linked to other Environmental Control and Life Support Systems (ECLSS) such as Atmosphere Revitalization (AR), Temperature and Humidity Control (THC), and Waste Management (WM). The complexity of this system dictates that a hydraulic simulation should be performed to determine the flow characteristics of the system. The FLUINT analysis package is used in the model to determine the flow and pressure characteristics when each of the different loop components are operational and contributing to the overall flow pattern.