The Aqua Alsietina Aqueduct is one of the least interesting ones in Rome, since it was completely underground and few traces are left of it.
Aqua Alsietina Aqueduct Rome
It was constructed by Augustus, when he needed water for his Naumachia. This was constructed in the year 2 BC, when he inaugurated the Temple of Mars Ultor in the Forum of Augustus.
Naumachia was both the word for a mock naval battle and for the area where this battle was staged, in this case a site of roughly 500 by 350 meters situated between the present Piazza Mastai and the Piazza San Cosimato in the Trastevere district.
The water of the Alsietina Aqueduct came from the lakes of Bracciano and Martignano. The latter was called the Lacus Alsietinus at the time, hence the name of the aqueduct. Since its use was solely meant for Augustus‘ hobby its quality was low and it was not drinkable.
Inscriptions on both the Fontana dell’Aqua Paola and the Arco di Tiradiavoli in Rome claim that these monuments were part of Pope Paul V‘s restoration of the Aqua Alsietina, but this was a mistake, since they actually restored the Aqua Traiana instead.
The Aqua Alsietina is also sometimes called the Aqua Augusta.