Historical data on river flow, nutrient and dissolved organic carbon (DOC) concentrations and phytoplankton were investigated to evaluate how these parameters change between low flow and high flow periods. Data were provided by SA Water, the Murray-Darling Basin Authority and the South Australian Environment Protection Authority. The databases were combined and data were plotted to identify sites and parameters where sufficient data existed for investigation. Several sites in the South Australian section of the River Murray were included and sites upstream were included in order to identify sources of nutrients and phytoplankton. Not all sites had sufficient data for all parameters, but sites investigated were: •River Murray at Me...