Changes in the quality of Nile water in Egypt during the twenty-five years, 1954–1979

Summary The study describes the variation in the chemical constituents of the Nile water at Giza, through the twenty-five years from 1954 to 1979 i.e., before and after the construction of the High Dam at Aswan.The total soluble salt content increased significantly by 29% after the construction of the High Dam, mainly due to the seepage of drainage water from the cultivated land of the Nile Valley. The SO4 _inf4 ^– , Cl^–, K⁺, Na⁺ & Mg⁺⁺ content increased significantly during the period of study, while the increase in pH values, HCO _inf3 ^– and Ca⁺⁺ contents was not significant.The suspended matter content decreased significantly by 94% from 1964 to 1979 due to the effect of the High Dam. The increase in silica content was significant while the decrease in oxygen content was not significant. No obvious variations were detected in chloride content, total alkalinity and total hardness during the study period.According to the ionic coefficients ratios and the geochemical classification, Nile water currently can be evaluated for irrigation purposes as falling within the class excellent — good and highly satisfactory for domestic purposes.