Cloaca Maxima

Construction and history

According to tradition, it may have initially been constructed around 600 BC under the orders of the king of Rome, Tarquinius Priscus. He ordered Etruscan workers and the plebeians to construct the drainage. Before constructing the Cloaca Maxima, Priscus, and his son Tarquinius Superbus, worked to transform the land by the Roman forum from a swamp into a solid building ground, thus reclaiming the Velabrum. In order to achieve this, they filled it up with 10-20,000 cubic meters of soil, gravel, and debris.

At the beginning of the drainage's life it consisted of open-air channels lined up with bricks centered around a main pipe. At this stage it might have had no roof. However, wooden holes spread throughout the sewer indicate that wooden bridges may have been built over it, which possibly functioned as a roof. Alternatively, the holes could have functioned as a support for the scaffolding needed to construct the drainage. The Cloaca Maxima may also have originally been an open drain, formed from streams originating from three of the neighboring hills, that were channeled through the main Forum and then on to the Tiber. As building space within the city became more valuable, the drain was gradually built over.

By the time of the late Roman Republic this drainage became the city's main storm drain. It developed into a system 1,600 meters long. By the second century BC, it had a 101 meter long canal which was covered up and expanded into also function as the main urban sewer system. Pliny the Elder, writing in the late 1st century, describes the early Cloaca Maxima as "large enough to allow the passage of a wagon loaded with hay." Eventually, the drainage could not continue growing to keep up with the expanding city. Romans would discard waste through other openings rather than the sewers. From 31 BC to 192 AD manholes could be used to access the drainage, which could be traversed by canal at this point. Manholes were decorated with marble reliefs, and canals were made of Roman concrete and flint.

The eleven aqueducts which supplied water to Rome by the 1st century AD were finally channeled into this drainage system after having supplied many of the public baths such as the Baths of Diocletian and the Baths of Trajan, as well as the public fountains, imperial palaces and private houses. The continuous supply of running water helped to remove wastes and keep the drainage system clear of obstructions. The best waters were reserved for portable drinking supplies, and the second quality waters would be used by the baths, the outfalls of which connected to the sewer network under the streets of the city. The Cloaca Maxima drainage system was well maintained throughout the life of the Roman Empire and even today drains rainwater and debris from the center of town, below the ancient Forum, Velabrum, and the Forum Boarium. In more recent times, the remaining passages have been connected to the modern-day urban drainage system, mainly to cope with problems of backwash from the river.

After the fall of the Roman empire the Cloaca Maxima continued to be used. In the 1600s Cardinal Chamberlain imposed a tax on residents of Rome in order to pay for the upkeep of the drainage. By the time of the 1800s the Cloaca Maxima became popular as a tourist attraction. From 1842 to 1852 sections of the drainage system were drained. Pietro Narducci, an Italian engineer was hired by the city of Rome to survey and restore the parts of the drainage by the Forum and the Torre dei Conti in 1862. In 1890 Otto Ludwig Richter, a German archaeologist created a map of the drainage. These efforts renewed public interest in sanitation.