This final chapter incorporates key research results over the past two decades that built on the theory of the first ten chapters. The theory of single buoyant jet is extended to multiple buoyant jet discharges. Multiple buoyant jets can interact dynamically under ‘starved plume’ condition when the jet entrainment flows are confined, and kinematically due to the merging and overlap of adjacent jets from a jet group. A semi-analytical model that predicts the dynamic interaction of multiple buoyant jets is presented. The jet-induced external flow is computed by a distribution of point sinks along multiple free jet trajectories obtained using integral jet models based on a well-established shear entrainment hypothesis. Under typical ocean outfall configurations and ambient crossflows, the dynamic interaction among jets can be shown to be insignificant theoretically and experimentally. Based on this observation, a general approach in predicting the dilution of rosette jet groups is presented—the composite dilution concept. The Lagrangian jet model VISJET, in which the composite dilution has been incorporated, is used to interpret the experimental results of multiple buoyant jet discharges. It is found that the VISJET can satisfactorily predict the trajectories and dilution of the rosette-shaped multiple jets; the predictions are also in good agreement with various independent studies under unstratified, uniformly stratified, and non-linearly stratified ambient conditions. By treating the action of the jets on the outside flow as distributed entrainment sinks, a dynamic coupling of the near field buoyant jet model and far field circulation model can be made at “grid cell” level using the Distributed Entrainment Sink Approach (DESA). The DESA method is generally applicable to both laboratory experimental and prototype scale flows and has been validated extensively against data of complex flow cases (Choi and Lee 2007).