Pollution flushing of tidal harbors has been elegantly modeled using analytical techniques for conditions that enable direct integration of the relevant equations during the flood and ebb tidal cycles [1]. Such analytical techniques, though limited to simple pollution loading and geometric conditions, give excellent agreement with physical models run under similar conditions and, hence, provide a yardstick against which alternative numerical formulations may be judged. The present work develops a Stella model, which replicates the results of the analytical approach and offers several features that extend the utility of the basic tidal prism model. These additional features include the ability to model harbors with more r...