Phytoplankton density at three stations along the length of the dam was studied. The drop method was used for the determination of the phytoplankton density. A total of four families made up of 20 genera were identified. No significant difference at 5% level of the ANOVA test on the values of temperature, conductivity, dissolved O2, alkalinity and dissolved CO2 at the stations. There is a significant difference of the values of nitrate at the stations. The difference in nitrate content at the station was due to the rate at which particles settled as the water of the dam flowed downstream.