Evaluation and analysis of water pollution in addition to reliable estimates of the environmental damages may help in establishing governmental regulations for environmental protection. Utilization and introduction to such estimates require knowledge of some processes, e.g. formation of a water line in the water stream, transport of pollutants, capability of self-cleaning, etc. These processes are recognized as complex, highly interacting and spatially distributed making analyzing, describing, modeling and even simulating them are challenging tasks. However, explicit solutions are possible in certain cases, which are physically very simple but are real enough to be of engineering importance. On the hand, for the less simple cases, numerical techniques can be developed which yield solutions of satisfactory accuracy. This research aims to investigate the possibility of applying numerical simulation for pollutants transport in open drains using the water quality model QUAL2K. The QUAL2K model was applied for Bahr Hadus drain system, then, calibrated using coefficients determined for the calibration period (water year 2010). Then, the model was verified and evaluated within a precise comparison for its predictions with the field observed data. Some different scenarios were simulated for Bahr Hadus drain and the model was used to forecast the selected water quality parameters along different locations on the drain. These scenarios were as follows: Scenario A and B simulated the cases when the discharges that pass through the Bahr Hadus drain and its tributaries were reduced up to 10% and 25% respectively. Scenario C simulated the case when the salinity was reduced up to 25%. The QUAL2K model represented the field date quite well in the two examined parameters and was able to simulate the previous Scenarios A. B and C, effectively.