Prediction equations were developed from the 1967 water quality data at 16 lake stations in the Grand River outlet area of Lake Erie. These equations were determined by multiple regression techniques (with transforms) on a trial-and-error basis using the following independent variables: 1. wind force and direction; 2. loadings of the Grand River at the outlet; 3. geographical location of the lake station (up to 5 miles from the outlet); and, 4. depth and temperature gradient with depth at the lake station. Individual equations were developed for each of the following parameters: 1. maximum turbidity; 2. average turbidity; 3. maximum conductivity; 4. maximum total phosphate; 5. maximum soluble phosphate maximum dissolved oxygen; 6. minimum dissolved oxygen; and, 7. maximum nitrate. As a check on the equations, they were tested on the 1966 data and found to predict the measured water quality parameters.