The Cornell Mixing Zone Expert System (CORMIX) consists of a series of software systems for the analysis, prediction, and design of aqueous discharges into watercourses, with emphasis on the geometry and dilution characteristics of the initial mixing zone, including the evaluation of regulatory requirements. This USEPA-approved system emphasizes prediction of plume boundary interaction and provides extensive documentation of input data verification, hydrodynamic model selection, and documentation of simulation results. New system features include an intelligent forms-based Windows 95/98/NT/2000 graphical user interface (GUI) denoted as CORMIX-GI, which provides access to advanced design tools for outfall visualization (CorSpy), mixing zone visualization (CorVue), access to legacy data (CorData), and sensitivity study analysis (CorSens). The CORMIX1 (submerged single port) and CORMIX2 (submerged multiport) subsystems can simulate mixing from dense discharge sources such as desalination facility brine discharges.