During the first years of reservoir filling (1986-1990) it was observed that the trend of daily inflow to the regulating reservoir is increasing which coincide with the daily water level
trend as shown in Figure (5 and 6).This increasing gave an indication that the capacity of the hydroelectric generation of the pump storage scheme have increased too, while during the
second period considered in this study (1994-2007) the inflow trend of the reservoir is decreasing coinciding with the water level trend