The was not a language called Roman. The Romans were Latins and spoke Latin. Water in Latin is aqua.
The Roman God of water is Neptune.
Since latin word for water is aqua then the modern roman would spell it out as acqua.
The channels or pipes that brought water to where it was needed were called aqueducts.
An Aqueduct is the answer. And to embellish this a bit more, I believe there is an aqueduct in Rome that still functions. Perhaps it has been closed down, but years ago when I was a student studying ancient Rome, the aqueduct was working.
The aqueducts carried water from the sources on the mountains to the Roman towns.
The functional units of the Roman water-carrying system were called aqueducts.
The Roman engineers built aqueducts to transport water to where it was needed.
The water supply for the Roman baths came from the same source as all water in Rome, the aqueducts.
The gardens had waterways to get water to the gardens as the roman did.
They constructed Aqueducts to carry water from the mountains to the Roman settlements.
It came into the towns on Roman "aqueducts".
The Mediterranean Sea was the body of water completely surrounded by the Roman Empire.