As with so many other aspects of the city, Augustus was responsible for dramatic renovations and innovations to the city's water supply Most of these actions were not undertaken by Augustus personally but rather were the work of Augustus's friend, assistant, and general, Marcus Vipsa-nius Agrippa. After the devastation and confusion produced by decades of civil war during the Late Republic, the city's infrastructure had fallen into serious disrepair, and in 33 bc, Agrippa assumed the office of urban aedile and began an aggressive program to repair and modernize the city's essential services. Among the areas that Agrippa turned his attention to was the water supply. He repaired and rebuilt the existing aqueducts as well as constructing new ones.
One of these new ones was the Aqua Julia, which ran for nearly 22 kilometers and could carry around 31,000 cubic meters of water per day. To save on new construction costs, most of the course of the Aqua Julia, as well as the Aqua Tepula, was built on top of the already existing Aqua Marcia, creating a triple-decker aqueduct. Along sections of the aqueduct near Rome, where there is a break in the arcade, the three channels of these aqueducts can clearly be seen, one on top of the other. However, the arches of the Marcia were not designed to support this additional weight, causing problems with portions of the aqueduct cracking or settling. Later Romans repeatedly had to add extra supports to the Marcia to bear this weight.
Agrippa erected a number of buildings in the Campus Martius, including a public bath complex, and in order to provide an adequate supply of water to this newly developed region of the city, he constructed the Aqua Virgo. There are various explanations for how the aqueduct got this unusual name, but the one recounted by Frontinus says that it was a young girl {virgo in Latin) who showed the Roman engineers the location of the springs that were its source. The Virgo, 20 kilometers in length, is notable because it was one of the few not to come from the Anio Valley to the east; instead, it drew its water and entered the city from the north. This aqueduct also had perhaps the longest lifetime in terms of continual operation, being used as a source of water up to the modem era. It carried about 104,000 cubic meters of water per day.
The third and final Augustan-era aqueduct was the Aqua Alsietina, which also drew its water from the north, in this case from Lake Alsietinus, and it served the Transtiberim region. This aqueduct had poor-quality water for drinking but was constructed specifically to provide water for naumachia, "aquatic spectacles," which Augustus staged to entertain the populace on the western bank of the Tiber. It was 33 kilometers long and had a capacity of 16,000 cubic meters of water per day. In addition to building aqueducts, Agrippa rebuilt and added to the distribution network within the city, including the construction of 700 basins, 500 public fountains, and 130 distribution reservoirs. These practical structures were adorned with 300 bronze or marble statues and 400 marble pillars.
As significant as the Augustan-era additions to the physical infrastructure were, the accompanying reorganization of the administrative structure was no less important. To continue the kind of supervisory role played by Agrippa, Augustus set up the permanent office of curator aquarum to be responsible for overseeing the water supply, with the charge that he ensure "that the water may flow to the reservoirs and public fountains without interruption day and night" (Frontinus, De Aquis Urbis Romae 103). Originally this office consisted of a board of men but was later reduced to a single curator. The headquarters of the curator would eventually be established at the Porticus Minucia, the location of the grain supply administration. The curator was assisted by a full staff, including surveyors, scribes, and engineers.
Agrippa organized a gang of 240 of his own slaves who were trained in maintaining and repairing the aqueduct system, and he bequeathed this group to the state so that they became a permanent feature of the office. Later, this group was augmented by an additional unit of 460 slaves established by the emperor Claudius. The office of curator aquarum appears to have been a fairly prestigious post, entrusted only to experienced administrators, as exemplified by the career of Frontinus, who had already held most of the higher posts in the Roman administration prior to being appointed curator aquarum.
Augustus and his agents certainly were responsible for fundamentally reorganizing and improving the entire water system. Once when a crowd of people was complaining about the high price of wine, he lost his temper and rebuked them, saying, "My son-in-law Agrippa by building several aqueducts has ensured that no one has to go thirsty" (Suetonius, Life of Augustus 42).
Later emperors continued to add new aqueducts to the city. The most important additions were made by the emperor Claudius, who built the Aqua Claudia and the Aqua Anio Novus. Water from both of these came from the Anio Valley, and both were also among the largest of the aqueducts, with the Claudia having a capacity of 191,000 cubic meters per day and the Anio Novus 197,000. They were among the longest aqueducts, the Claudia being 67 kilometers in length and the Anio Novus 87 kilometers. Of the 11 main aqueducts, the final two were the Aqua Traiana built by the emperor Trajan in ad 109 (58 kilometers) and the Aqua Alexandrina built by the emperor Severus Alexander in ad 226 (22 kilometers).
Aqueducts require constant maintenance to patch leaks and to remove mineral deposits, which can otherwise block the channels. While it is clear that some of the aqueducts remained in use long after the fall of the
Figure 3.2 Portrait of Marcus Vipsanius Agrippa, Augustus's friend and general who expanded and rebuilt Rome's sewers and aqueducts,
Roman Empire, it is difficult to accurately trace the fortunes of any individual aqueduct. During the war with the barbarian king Vitigis in ad 537, the aqueducts were severed in an attempt to cut off the city's water supply. However, there seem to have been subsequent repairs, and in the 770s, at least four, including the Claudia, Virgo, and Traiana, were still in service.
HOW THE WATER SYSTEM FUNCTIONED
One of the interesting characteristics of the Roman water-supply system that differentiates it from modern water systems is that the Roman one was a continual-flow system. The water passed through the pipes and into and out of the fountains and basins constantly, whether people were using them or not. Overall, there were few valves to turn the flow of water on and off. The entire system operated by gravity. There was minimal to no use of pumps, so the elevation of the water was vitally important. The entire course of the aqueduct had to be carefully graded so that the water flowed fast enough to prevent stagnant pools or backflow, but not so fast that it became difficult to deal with. The average gradient in the Roman aqueduct system seems to have been about a three-meter drop in elevation per kilometer of distance.
The velocity of the water in the pipes would have been around 1 to 1.5 meters per second, although in some spots it might have flowed as quickly as 4 meters per second. At these typical rates, it might have taken about a day for water to travel from the farthest source to the city. Channels through which the water flowed were made from a variety of materials.
Figure 3.3 Cross-section of aqueduct showing the covered channel through which the water flowed.
Including stone lined with hydraulic cement and pipes made of clay or lead.
At strategic points along the aqueducts, the water would enter large tanks or reservoirs. These served to stop the flow of water so that sediment or debris could be separated out. Water usually passed through a succession of these settling tanks so that by the time it reached consumers, it would hopefully have been fairly free of contaminants. In the city, the water was distributed to various storage towers called castella. From the castella, water was directed to the various access points, such as fountains, baths, or basins.
Only a tiny fraction of Romans had running water in their dwellings, but fountains or basins were located at nearly every street intersection. These probably served as focal points of neighborhood social interaction where people gathered to draw water and exchange gossip. Naturally, if you lived many stories up in a building, the daily routine of hauling water to your dwelling could have been quite arduous. Wealthy Romans would likely have had slaves whose job was to carry jars of water to their homes. One profession in Rome was the aquarius, the neighborhood water deliveryman who would bring water to your door for a fee. The satiric poet Juvenal mentions the aquarius as a stereotypical figure with whom sexually frustrated women would find relief (Juvenal, Satires 6.332).
Approximately one-third of the aqueduct water was consumed outside the city boundaries for purposes such as irrigation. Roughly another third went to the public fountains, baths, and basins. Of the remainder, a substantial part was used by the emperor, including the supply for the imperial baths. Water was a form of benefaction that the state supplied to the citizens. There was no fee for drawing water from the fountains, and even many of the great bath buildings were free or had only token admissions.
One of the greatest challenges faced by those charged with maintaining the system was the problem of privafe individuals illegally tapping into an aqueduct. People would bore holes into the aqueduct and then attach their own pipes to bring water to their dwellings or businesses. This was such a problem that the curatores had to have their staffs constantly patrolling all the exposed sections of aqueduct, and they were continually removing such illegal taps and fixing the holes they made. Frontinus identifies illegal tapping as a serious problem that could divert up to half the capacity of an aqueduct. Fie indignantly reports that he had found "fields, shops, apartments, and even brothels illegally hooked up to the system with private water taps" (Frontinus, De Aquis Urbis Roniae 76).
One of the greatest problems in assessing the Roman water-supply system from a modern perspective is that so much of our statistical evidence comes from Frontinus. While he supplies a great deal of numerical data, there is enormous scholarly debate about how these numbers should be interpreted. Much of this uncertainty stems from fhe fact that Frontinus expresses the volume of the aqueducts in terms of units called quinariae.
This is a measurement expressing the size of a cross section of pipe and as such does not take into account factors, such as the velocity of the water, that are essential to knowing the volume of water being transported. This has led to endless academic arguments about how to translate his figures, resulting in estimates of the total volume of water supplied to the city that range from 300,000 cubic meters per day to well over 1 million cubic meters per day.
The Romans built aqueducts not only for the capital city, but all over the empire as well, and these provincial aqueducts feature some of the most impressive architecture. The Pont du Card in southern France is an astonishing engineering feat consisting of a multilevel arcade 50 meters high built to carry an aqueduct across a gorge. The town of Segovia in Spain has a lengthy section of well-preserved and imposing aqueduct, and the city of Vienne in Gaul was served by no fewer than 11 aqueducts, although they are considerably smaller than Rome's.
Overall, the Roman water-supply system was a truly impressive achievement and one that the ancients themselves marveled at. Frontinus asked, "How could you compare such an array of indispensable structures carrying so much water with the idle pyramids or the useless although famous works of the Greeks?" (Frontinus, De Aquis Urbis Rontae 16). Pliny the Elder wrote, "If we take into careful account the plentiful supply of water to public buildings, baths, pools, canals, homes, gardens, and villas near the city; if we contemplate the distances traveled by the water before it arrives, the raising of arches, the tunneling through mountains, and the construction of level courses across deep valleys, we will have to concede that nothing more remarkable has ever existed in all the world" (Pliny the Elder, Natural History 36.24.123).
World History
