SUMMARY
The present article deals with the systems of supply and evacuation of water in some Roman sites of Algeria (Cherchell, Tipaza, Djemila, Timgad and Toudja). On the basis of investigations and a literature search on water in Roman urban areas, it appears that these sites are equipped with efficient hydraulic systems that can meet the needs of the population and protect cities against climatic hazards. This study brings some classical archaeological studies. The systems of water supply and evacuation studied follow schemes similar to the systems used in the remains of the Roman Empire, except singularities due mainly to local constraints especially topographical. Discharge estimation on two aqueducts (Cherchell and Toudja) allows us to get a clear idea on the water allocations at that time and also the comfort degree of the Roman cities.