Well, they did and they didn’t. During the days of the Roman Empire, the city of Rome was supplied with water by means of aqueducts, water-carrying pipes mounted on pillars or buried underground.
Aqueducts brought water from nearby mountains to public water fountains in the city, and most Romans got their water from these fountains.
Some wealthy Romans connected the city’s water mains to their homes and piped in cold running water. These pipes almost never reached above the first floor of a Roman house, though, so in general most Romans didn’t have running water in
At its peak, the aqueduct system of Rome brought 300 million gallons of fresh water to the city each day!