Bacteriological quality of Nile water before and after impoundment (1963--1973): a review

The normal old picture of the river Nile during 1963 -- 1965 revealed that the rise and fall in bacterial counts followed the seasonal changes. Thus, the highest bacterial counts (10(7) -- 10(9)) 100 ml) were recorded during flood season. Otherwise, a phase of decline (10(5) -- 10(7)/100 ml) prevailed during the whole year. After complete storage, i.e., during (1970 -- 1973, the complete abolishment of seasonal fluctuation was recorded. Secondly, a drop in bacterial counts (10(5) -- 10(7) 100 ml) marked the impoundment water. Thirdly, a rise in coliform and faecal Streptococcus density was recorded in the river water. Moreover, a higher incidence of coliforms and faecal streptococci, untyped forms, marked the river water after full lake storage.