Module JET, also known as MOHIDJET integral model, aims to simulate the initial dilution associated to outfalls jets. The model is used as an initial condition of Lagrangian tracers module, used to simulate plume dispersion in the far field. Therefore, MOHIDJET is a very helpful tool to simulate the impact of outfalls water bodies integrating the near field (MOHIDJET) with the far field (MOHID). A Lagrangian approach was used in MOHIDJET similar to the one use in the JETLAG model (Lee and Cheung, 1990 ) where the trajectory and volume variation of a tracer with a cylindrical geometry are simulated. However, for the entrainment parametrization was used the work of Jirka(1999). This author is one of the main contributors to the development of CORJET(Cornell Buoyant Jet Integral Model) the buoyant jet model of CORMIX (Cornell Mixing Zone Expert System).