Literature reviews on various stream processes which contribute to reoxygenation and deoxygenation was presented. These processes include atmospheric reaeration, photosynthesis-respiration, biochemical oxygen consumption, and benthic demand. Measuring these parameters in a selected stream is a complex and costly operation. On the other hand, prediction models developed are specific to particular location and environmental conditions and can only be applied to similar situations. Computer models such as "RIVER" are available and could be used to predict dissolved oxygen concentrations along a waterway for a specified set of stream conditions. The model "RIVER" was calibrated by using the existing conditions of flow and water quality parameters along Phillippi Creek, Sarasota County, Florida. Also treatment requirements which could eliminate dissolved oxygen violations were predicted.