MainBanner.jpg (19725 bytes)

A webpage created for Archaeology of Rome

by Casey Kraftick

ConsButton.jpg (2746 bytes) RoadsButton.jpg (2182 bytes) AquaButton.jpg (3055 bytes) SewersButton.jpg (2379 bytes)

Roman Water Infrastructure
The Roman water infrastructure consisted of four main areas, water conduction, drainage of lands, canals, and harbors. The area which will be given the most attention is that of water conduction, however, the other three areas are also very interesting. The Roman system for water conduction, at it's peak at around 300 AD, consisted of 11 aqueducts. These 11 aqueducts supplied the city with approximately 1,168,850 cubic meters of water per day. This is an astounding number compared to today's standards, averaging out to about 200 gallons per person per day.

By the end of the third century BC it became necessary to regulate the torrential floods of the Tiber River. This was done by enclosing the river in stone embankments laid out in stepped stages. This method proved to be very effective, and was also used to regulate the Arno River.

Other notable efforts were accomplished in the drainage of land for farming. In 280 BC Manius Curius Dentalus drained the marshes of Rieti by cutting a 2,624-foot-long canal which was led deliberately to a precipice, forming a dramatic waterfall. In 109 BC work on reclaiming the Po Valley was begun under the direction of Aemilius Scaurus for the purpose of settling veteran soldiers as farmers. This was done by cutting a system of canals through the valley which were also used for navigation. The reclamation in this previously uninhabitable area went on for hundreds of years. This fertile area, known as Cisalpine Gaul, became the "cockpit of creativity in the western world."

One notable project involving roman reclamation efforts can be found in the Facinus Emissarium. This was a project ordered by Emperor Claudius which involved lowering the level of the Lacus Fucinus in order to gain approximately 38,000 acres of new farmland. This project required the digging of a 3.5 mile long tunnel through rock. The tunnel was completed after 30,000 men labored for 11 years.

The enormous and monumental works accomplished under the Roman Empire were largely a result of totalitarian power. It was the availability of free labor provided by slaves, and the ability of the Emperor to exert his totalitarian power which made possible these capital and labor intensive projects. The aqueducts of Rome are an extraordinary example of engineering. What remains of these great structures are monuments of construction that was well ahead of its time.
At its peak, Rome's system of 11 aqueducts measured 312 miles long, with 262 miles consisting of underground tunnels, and the rest being arched structures. The total capacity of this system was approximately 1 million cubic meters of water every 24 hours. To put this in perspective, the present day District of Columbia is about the same size Rome was in AD 300, and can provide roughly 67 gallons of water per person. The aqueduct system in Rome in AD 300 provided an estimated 200 gallons of water per person. A lot of this water was used to supply public fountains and baths. These figures are astonishing, and reflect the vast size and excellent overall quality of the Roman water network.

pontduGard.jpg (54024 bytes)

Building an aqueduct involved one main concern; leveling. When an aqueduct followed a river, the grade of the river could be followed and used as a reference. However, when the Roman engineers had to construct aqueducts through the hills, maintaining the correct gradient became more difficult. The leveling was done using a tool called the chorobates, which was a 20 foot long board that could be leveled with a plumbline, or by filling a groove cut in the top with water. Using this tool an experienced tunnel builder could establish a grade with an accuracy of 1:2000.

In order to maintain grade over river crossings and gorges, spectacular arched bridge constructions called viaducts were built to carry the conduit. The size of some of these structures was astounding. Due to the large above ground structures, and the amount of tunneling that was required to complete an aqueduct, these projects usually took many years, and involved mobilizing hordes of workers. The enormous labor force consisted of slaves, or prisoners of war. Because the overseers of such projects realized that better treatment resulted in better performance, these slaves were treated very well, and many were eventually integrated to became Roman citizens.

When the aqueducts were cut in soft ground they were lined with masonry. When they were cut through rock they were left unlined. The above ground arches were built entirely of stone in the earlier aqueducts, but in the later aqueducts the main specus was made of a rough concrete, and faced with stone. At the source of each aqueduct there was a settling tank to remove solids from the water preventing the clogging or silting up of the conduits. In the city each aqueduct ended in a castellum, or distribution basin. This basin had three outlets at the lower level which served fountains, baths, and public buildings, and higher up in the basin were the outlets that served private consumers. Overflow was used to flush drains, or turn water wheels.

Most of what is currently known about the Roman system of aqueducts was derived from a book written by Sextus Julius Frontinus, who served as the Curator Aquarium from AD 97 to AD 104. He was appointed to this office by Nerva in order to restore the long neglected and abused water system. Frontinus was very instrumental in restoring the aqueducts, and doing away with the corruption, and fraudulent practices that had left the system in a state of disrepair.

Frontinus kept very accurate records, by taking inventory of the entire system, and detailing the technical aspects of how such a system should be maintained. After correcting all of the problems that had occurred, Frontinus began making improvements to the system in order to make it more efficient. In order to ensure that the work he had done would continue when he left office, Frontinus set a standard to be followed, and wrote a number of bills that were enacted by the Roman Senate.

Just as all great things must come to an end, so did the Roman system of aqueducts. As was pointed out previously, with a water distribution system of this scale, a continuous maintenance effort is required. Otherwise the system will deteriorate and fall into disrepair and disuse. When the Roman economy went into decline, so did the water infrastructure.

The final destruction of the Roman system of aqueducts occurred in 537 AD during a siege on Rome by the Goths. The Goths built an encampment between two lines of arches of the Aqua Claudia, and the Anio Vetus, in which they housed 7,000 troops. From this fortification they conducted raids on Rome, and demolished the aqueducts in an effort to deprive the city of water. They even attempted to send troops through the dry conduits to attack the city. After the siege, there was an effort to repair the aqueducts, but they eventually fell to disrepair and neglect, with the exception of Aqua Virgo, which remains in use today.

Back to Roman Roads!      On to Roman Sewers!