CCME WQI values of Bahr ElBaqar Drain indicated that water quality for aquatic uses could be related as poorto marginal (Fig. 4). The temporal trend significance increases (P < 0.05; Table 3). Unstandardized (B) regression coefficient indicates how much the dependent variable goes up, on average, given that the independent variable goesup one unit. Therefore, for independent variable (year of measurement), the coefficient 0.928 (Table 3) means that anincrease of one year (independent variable) corresponds to an increase of 0.928 (less than 1) points of WQI (dependentvariable). Hence, the rate of improvement in water quality is very slow. Consequently, WQI score is 37–48 over testedperiod.