The results of a remote sensing study have been correlated with previous research on estuarine mixing processes and with ground sampling investigations to appraise the dispersal of effluent in the Tay estuary. The advantages of using remote sensing techniques to study the distribution of convergent fronts and their effect on the dispersal of effluent are demonstrated. The application of remote sensing data in the study of the near-shore dispersion from outfalls and the short-term dispersal behaviour of outfalls are discussed with reference to two particular sewer outfalls. The results of the remote sensing studies correlate highly with ground studies of the same areas. A modified simulation model of the flushing capacity of the Tay estuary has been developed incorporating the results of the remote sensing study. The results of the model are very similar to those calculated from a physical model. The preliminary results of a study to integrate urban hydrological and outfall dispersal models with remote sensing data are reviewed.