This study was carried out on Rosetta branch water and 3 drains (El-Rahawy, El-Soble and El-Gezira) that discharging wastewater into it, to assess the Water Quality Index (WQI) of their waters. This investigation was performed during the period starting from winter 2017 to summer 2018. The mean annual averages of WQI values of Rosetta branch Water were good to poor for irrigation (up to 55) and from poor to very poor for aquatic life (up to 97) at stations exposed to wastewater discharged from drains into water branch. The obtained values of physical and chemical variables of Rosetta branch and drains water were matched with the standard values set by FAO (1994) for irrigation and Canadian Water Quality Guidelines (2011) for aquatic life. The obtained results indicated that the values of examined variables were higher than the recommended standards which affects the environmental live in this area and producing healthy problems. The concentrations of physical and chemical parameter were higher during winter than summer.