Cloaca Maxima (“largest sewer”) was one of the largest Roman structures ever built. The ancient Romans completed the construction of the sewer that passed through Forum Romanum, in the 6th century BCE.
According to Roman sources, the ordering party was king Tarquinius Priscus himself. The canal was built to drain wetlands in the valley between the Esquiline, Viminal and Quirinal hills. The Forum Romanum was established in the drained area. The stream flowing in this place was deepened and its banks were strengthened. The waters were drained to the Tiber.
Titus Livius reports that the sewer was cut underground during the reign of Tarquinius the Delicious – the last king of Rome, and the works were attended by Etruscan engineers and large masses of the urban poor:
Being intent upon completing the temple, the king called in workmen from every quarter of Etruria, and used for this purpose not only the state funds but labourers drawn from the commons. This work was far from light in itself, and was added to their military service. Yet the plebeians felt less abused at having to build with their own hands the temples of the gods, than they did when they came to be transferred to other tasks also, which, while less in show, were yet rather more laborious. I mean the erection of seats in the circus, and the construction underground of the Great Sewer, as a receptacle for all the offscourings of the City — two works for which the new splendour of these days has scarcely been able to produce a match.
– Titus Livius, Ab urbe condita, I 56
It seems, however, that Livy was mistaken in writing centuries after these events. According to other sources, the channel was still open during the reign of Tarquinius Superbus.
It wasn’t until 184 BCE thanks to censor Cato the Elder the sewer was blocked and the sewage was flowing underground. As a token of recognition, his statuette was placed in the temple. However, the biggest maintenance work took place during the reign of Octavian August when his friend Agrippa oversaw all construction and repair works.
It is widely claimed that Cloaca Maxima is still in use today, which is to prove the engineering genius of the Romans. The truth is that water does indeed still flow through the Roman canals, but it is only a trickle.
There are a few places on the surface of the earth where we can see pieces of Cloaca Maxima; n and for example, the mouth of the canals is south of the Ponte Rotto bridge. Another place where you can see a fragment of the canals is the eastern staircase to Basilica Julia, in the Forum Romanum. There is a lead door that leads to the underground complex. While standing by the door, you can feel and hear the water flowing in the sewers.
It is also worth mentioning that in Rome – at the Forum Romanum – there was a special temple dedicated to Venus Cloacina, or “Venus of the Canals”. The Romans themselves did not fully understand the sense of creating this tabernacle.