SUMMARY
Wadis Mellah and Mikéss and on the bacteriological quality of the water dam Sidi Chahed: to determine the contribution of the two wadis supplying this work aims.This study focused on three stations: upstream in Wadi Mekkes another ups tream in Wadi Mellah, and sampling at the surface of the dam.Bacteriological analysis focused on indicators of pollution which include germs, germs total, total coliforms, fecal coliforms, fecal streptococci, and sulphite-reducing anaerobes. Statistical analyzes showed that the pollutant load brought by the waters of Wadi Mellah Mekkes and are more important than that provided by the waters of the dam, and that fecal pollution.