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Nomine Caesaris: An Examination of the Propagandistic Functions of the Aqueducts of Rome During the Early Empire


Matthew Keith Malott

(University of Windsor)

The aqueducts of Rome were an achievement in hydraulic engineering which remained without equal for centuries. The Romans' elegant and effective water supply system is considered to be one of their greatest technological enterprises, and it spread out from Rome as a model for water management, covering all corners of the Empire, and becoming one of the standard features of any noteworthy Roman city.

However, amidst the praise for the technological innovation of the aqueducts, their deeper, symbolic meaning is often disregarded. It is my intention in writing this paper to show that the aqueducts of Rome employed a simple yet very effective system of propaganda in addition to their engineering genius. This propagandistic function evolved over time, and was employed fully by the Julio-Claudian Emperors, especially Augustus. They used the aqueducts not only for water distribution, but also to create among the common people the illusion of total dependency on the state for even the most basic of human needs. The aqueducts were always a free public endeavor, and they were extremely expensive to build and maintain, but the symbolic message they delivered to the hundreds of thousands of citizens who depended (or believed that they depended) on them for water was well worth their cost. The aqueducts were, in a sense, a medium for the delivery of propaganda tailored to common Romans. Whereas sculpture, painting, and other "high" forms of Roman art in the early Empire often had propagandistic functions which were aimed primarily at the ideology and tastes of the upper class, the aqueducts appealed to the masses using the basic ideology of survival, which was often the only one that a common Roman could afford to consider. Those who were not as cultured and artistically literate as the aristocracy, or who were unable to experience the splendor of finely carved sculpture and meticulously rendered paintings on account of social status or financial unfeasibility were subordinated by the hand of the state through the aqueducts. Through the aqueducts, the Julio-Claudians made themselves out to be the only supplier of the most precious resource to all the citizens of Rome — a very important image to maintain in a system of dynastic monarchy — and made sure that this was never forgotten.

I will not make any claims here about the thoroughness of my discussions on the aqueducts, as making such a claim would be foolish for a paper of this size. Instead, I will briefly discuss the technical specifics of aqueducts, and then proceed with a very different sort of analysis. Indeed, analyzing the social ramifications of the aqueducts is not an easy task, since the great majority of any surviving ancient literature as well as most modern scholarly work about them is technical in nature. Thus, I will be looking at very precise passages in the ancient authors, which are, to say the least, scanty and vague, and I cannot claim that the conclusions I intend to draw are rock solid. But one must bear in mind that the only "rock solid" data one can ever extrapolate about the aqueducts is entirely technical. After a short discussion on the construction of aqueducts, I will proceed to examine the other sources of water available to Romans, and how the evidence for a plentiful supply of good quality water in and around the city casts doubt on whether the aqueducts were every truly a necessity for anything save possibly the supply of public monuments and the luxury of private consumers. I will then examine how the aqueducts of the Republican period differed from those of the Imperial period constructed under Augustus and later Claudius, and the conclusions we can draw from the evidence provided by our sources that aqueducts became much more pervasive, visible, and ostentatious under the Julio-Claudians. I will then proceed to analyze some statistics regarding the number of public fountains in Rome, compared with how much water from the aqueducts actually went to them, and what this can tell us about their necessity and their uses. I will also examine representations of aqueducts on Roman coins, the only medium in which they appear, and how the types of Roman coins we find aqueducts on lead to the conclusion that it was indeed the poor of Rome who were intended to be affected by the aqueducts' system of survival propaganda.

In writing this essay, I will use three primary sources: Sextus Julius Frontinus' De Aquis Urbis Romae, Vitruvius' De Architectura, and some short selections from the Elder Pliny's Historia Naturalis. Frontinus was appointed the water commissioner of Rome by the Emperor Nerva in 97 A.D, and presumably held this post until his death. It is during this assignment that he wrote De Aquis Urbis Romae, and it is the most complete extant source on the aqueducts. Its focus is not, however, on how the aqueducts were built, but rather the technical specifications of each of the nine aqueducts of the city of Rome that existed in his time, and statistics related to the volume of water they produced. Vitruvius is an architect contemporary with Augustus, having written his ten books De Architectura around 16-13 B.C, and, obviously, is more concerned with the appropriate construction of aqueducts. Pliny offers some scattered comments which fall in both of these categories.

Of course, the engineering merits of the aqueducts cannot be overlooked no matter what the focus of one's research is. Thus, I will give a brief account of their construction and technical specifications. I will here be relating information mostly from Vitruvius, which does not actually tell us how the aqueducts at Rome were built, but rather the ideal manner in which one should go about the task.

The aqueducts of the city of Rome are called gravity-flow conduits, because they rely on a gradual slope for the guiding and movement of water rather than on pressure, as is the norm today. The process begins at the source of the water, which is usually on a higher elevation than the city. Ideally, there are two reservoirs, or castella, in the system: one at the source and one at the point of distribution, although Frontinus tells us that neither the Aqua Virgo, Appia, or Alsietina has a reservoir at the end of its route. A pipeline, or aqua, carries the water from the source to the city on a rigid slope of six inches in every hundred feet (Vitr. VIII. VI. 1). The pipeline should be vaulted over to prevent the sun from reaching the water (Vitr. VIII. VI. 1). These vaulted structures are given the name arcurationes. If the route of the aqua is impeded by a hill or mountain, Vitruvius advises the digging of a tunnel, or specus, with the same uniform slope of the rest of the aqua (Vitr. VIII. VI. 3). If the tunnel is being dug through volcanic tufa or "hard stone" as Vitruvius calls it, he recommends cutting the pipeline directly into the rock. However, if the tunnel is being dug through soft earth or sand, he advises on the construction of a vaulted channel (Vitr. VIII. VI. 3). Vitruvius also says that vertical shafts, or putei, should be cut into the tunnel from the surface every 120 Roman feet. These putei served to give access for maintenance, and also allow for the venting of water pressure which may have built up in the conduit (Temeanko 89). Vitruvius goes into detail on how to build an aqueduct using lead pipes. If the conduit is to be of lead, Vitruvius tells us that the lengths of pipe for the conduit must be no less than 10 feet long. He goes on to specify how heavy the pipes should be, depending on their circumference in digits. [FN 1] Herschel tells us that these pipes employed the same mortar of lime and oil which was used to finish the joints on the outside of buildings (Herschel 163). Vitruvius also speaks of ventres (literally "bellies"), also called substructiones, which are just that; substructures. In areas where there is a long stretch of low land, the pipeline is carried by substructiones to achieve as long of a level route as possible, and to prevent a sudden burst of pressure when the pipeline rises out of the valley (Vitr. VIII. VI. 5-6). He says that vents for built up pressure should be cut into the ventres just as they are in the specus (Vitr. VIII. VI. 6). Vitruvius also says that terracotta pipes are less expensive than lead, and are also more healthful. He describes the necessary measures for using terracotta as oppose to lead, such as jointing the pipes so that they may be tightly fixed together, and jointing a hollow block of red stone to elbows in the pipeline when it rises off of or descends onto a venter (Vitr. VIII. VI. 8-9). It is also important to note that the formula I have related here for construction of an aqueduct is based on the techniques of the first century B.C, when Vitruvius was writing his treatise.

Having touched upon their construction, I will now begin my more socially-oriented discussion of the aqueducts of Rome. My first consideration will be alternative sources of water in Rome. There is extensive evidence, both literary and archaeological, which shows that Rome had (and indeed still does have) a very abundant supply of water via natural springs and wells. Herschel says that the site of Rome is in fact ideal for a self-contained water supply. Its proximity to the Tiber means that Rome is situated directly on top of several small underground streams which produce an abundance of natural springs (Herschel 102). Herschel also claims that archaeological evidence proves that the groundwater in Rome rose several feet in the historic period (Herschel 103). The valleys of Rome were also plentiful with natural water sources. Herschel tells us that even today the ground around the temple of Castor and Pollux is full of natural springs, and even states that the ground under the Forum Romanum is so rich in groundwater that it is only due to the layers of earth rising over the course of the ages that this part of Rome can remain dry land, rather than reverting back to the swampy wetland it was before the building of the Cloaca Maxima (Herschel 105-106). [FN 2] Cicero relates the abundance of water in Rome as well in his De Republica when he says that Romulus "chose a place abounding in springs" (Cicero II. 6). Cassiodorus says that "Rome has a bountiful supply of water and is blessed with springs" (Letters III. 53. 1), and even by the time of Pliny the natural sources were still used, and even exalted, as Pliny himself states that the best water in Rome comes not from the aqueducts, but from the same wells that had been used for centuries (Pliny XXXI. 38). Frontinus corroborates this at the very beginning of De Aquis Urbis Romae: "the Romans were satisfied with such waters as they drew from the Tiber, from wells, or from springs. Esteem for Springs still continues" (Front. I. 1).

We must consider then what this evidence tells us about the functionality of the aqueducts for the common people. Certainly the water they provided was not urgently needed for the survival of the populace. It is true that the water of the Tiber became polluted over time, since the Cloaca Maxima flowed directly into it. This no doubt had an effect on the quality of water available at wells and springs, but as we saw, well water was still considered of a very high quality even in the first century A.D. So, while many common Romans may have preferred the convenience of public fountains and the guaranteed quality of their water, these were certainly not the only available source. Thus, common citizens, as much as they may have felt themselves indebted to the public service of the aqueducts, most certainly were not. For further proof of this, we need only examine Evans' statistics, extrapolated from Frontinus', whose are, to say the least, somewhat hard to follow. Only 1,335 quinariae, [FN 3] being a mere 13.4% of the total water delivered to the city, were used for public lacus (fountains) (Evans 140-141). Given this evidence, how then did the Roman state make its urban populace believe that they were dependent upon it for the most basic of human needs, even when they most definitely were not? The answer to this lies in the appearance of the aqueducts, and the pervasive number of public lacus which existed. These issues will be dealt with presently.

As I stated earlier, the people of Rome were in no way dependent upon the aqueducts to survive, but it was the wish of the state, especially the early Emperors, to make them believe that they were. How they were able to achieve this is in part due to the shift in aqueduct building techniques employed between the Republican and Imperial periods. Frontinus lays this out for us nicely when he says that "the ancients laid the lines of their aqueducts at a lower elevation ... But now, whenever a conduit has succumbed to old age, it is the practice to carry it ... on substructures or on arches ... abandoning the subterranean loops in the valleys" (Front. I. 18). The "loops" that Frontinus refers to are the tunnels of the older aqueducts, which actually seem to have avoided substructiones and arcurationes. Indeed, we find that the first aqueduct, the Aqua Appia of 312 B.C was carried above ground on substructures for only sixty out of 11,190 paces in length (Front. I. 5). Likewise, the next aqueduct to be built, the Aqua Anio Vetus (272-269 B.C) ran underground for 42,779 out of 43,000 paces (Front. I. 6). These earliest aqueducts do not serve any purpose of ostentatious display. They seem to be purely pragmatic ventures, and are kept for the most part out of sight. The Aqua Marcia of 144-140 B.C, on the other hand, begins to show signs of a shift towards more visible and grandiose display when constructing aqueducts, as it runs only 54,247 and one-half paces underground out of 61,710 and one-half. Though this is not a drastic difference, it is interesting to note that the Aqua Marcia runs its final 6,472 paces into the city on arches (Front. I. 7). The fact that its builder, Marcius Rex, chose to use arcurationes for the Marcia's arrival in the city when it was not necessary shows that by this time the idea of using the aqueducts to display the power of the state and create awe among the common people was more accepted. The Aqua Tepula of 125 B.C, which was the last aqueduct to be built during the Republic, shows marked change. Of course, it is important to note that a lacuna in Frontinus' text at I. 8 means that only the statistics of the Aqua Tepula after Agrippa refurbished it in 35-33 B.C survive. The refurbished Tepula runs nearly half of its length, 7,000 paces out of 15,426 and one-half, on above-ground masonry. This was considered enough of a change to warrant altering the aqueduct's official name to the Aqua Julia, although this new title never stuck, and it was still referred to as Tepula in Frontinus' time (Front. I. 9). The aqueduct that Agrippa built altogether in 19 B.C, the Aqua Virgo, runs for less than half of its 14,105 paces underground (Front. I. 10). I will not bother examining the Aqua Alsietina, a very small conduit that Augustus commissioned in 2 B.C mainly for the purpose of supplying water to his Naumachia [FN 4] in the Campus Martius, since Frontinus makes it clear that its water was not used for consumption (Front. I. 11). Caligula, in 38 A.D, began construction on two massive new conduits, but after his death it was left to Claudius to complete the project, which he did in 52 A.D. These two aqueducts, the Aqua Claudia and the Aqua Anio Novus were the longest and highest of all the nine aqueducts during the time of Frontinus. The Claudia arrives in the city on 6,491 paces of Arches (Front. I. 14). Interestingly enough, the Anio Novus comes into the city on arches of the exact same number of paces (Front. I. 15). Each of these conduits is nearly 50,000 paces long, and over 10,000 paces of each use above-ground masonry, most of this being close to or in the city.

We cannot take this obvious shift as a mere coincidence, and so this evidence leads to the conclusion that as the values of the Roman state shifted during the transition between Republic and Empire, and propaganda became inexorably linked with many facets of daily life, so too the aqueducts shifted in their appearance and construction methods to suit this change and be of the most use to the Emperors. Whereas the Republican magistrates saw fit to keep their aqueducts out of sight, the early Emperors made a point of keeping their aqueducts very much in it, so as to also keep them in the minds of the people. By forcing the Roman people to remember that their water came from aqueducts, and by making sure they could always observe this mechanism which was piously given to the people out of the state's pocket, they succeeded in obliterating the importance of those natural water resources which had supplied Rome very effectively and sufficiently for centuries. In the Republic, there was a greater sense of community and self-reliance among the Roman people; that is, the ideal that since every citizen had power of choice in matters of government leadership and (to a certain point) legislation, each citizen had very potent reasons to wish to protect the state. However, when Augustus claimed sole power, and a system of dynastic monarchy was put in place, this idea of self-reliance and community dwindled in the face of a supreme ruler who directed the affairs and interests of the state on his own. The early Emperors combated this dwindling sense of civic duty by using the aqueducts' propagandistic potential to replace self-interest in the state with dependence on the state, which proved to be much more effective in the end.

The next aspect of the aqueducts I will examine are the public fountains, or lacus, from which all citizens were free to draw water. What is most interesting to note for our purposes is that under Augustus, the number of public lacus was quintupled. Pliny gives us very specific details about Agrippa's program of building and decorating public lacus in Historia Naturalis XXXVI. 121-123, where he says that "Agrippa ... while aedile ... constructed 700 basins, along with 500 fountains (lacus) and 130 reservoirs, many of them magnificently decorated, and added 300 bronze and marble statues to these works, and 400 marble columns." Evans counts the number of public lacus mentioned by Frontinus at 591 (Evans 141), and so we may therefore deduce that only 91 lacus existed before Augustus. This was no doubt sufficient for the needs of the people, but obviously lacked the conspicuous ostentation that was needed for Augustus' propagandistic aims. We should not be fooled into thinking that the statues Agrippa used to decorate these fountains means that they no longer appealed in the basic way mentioned earlier; these statues were most likely mere eye candy to attract the attention of the common people and further prevent them from forgetting that they received free water Nomine Caesaris. [FN 5] In any case, we cannot believe that the addition of 500 public fountains was truly a necessity, especially since wells and springs were apparently still frequently used. However, by totally revamping the water system and making it more conspicuous and lavishly decorated, Augustus, and then Claudius after him, wanted to make the people forget that the older aqueducts survived from a time when the Emperor had no power. He wanted to erase the history of the aqueducts before him and suggest that they were his personal possession, and that although they were a free public service, the people still received their water by his generosity and permission.

There is an interesting passage in Frontinus which would seem to confirm the propagandistic functions of the public lacus built by Agrippa and Augustus. When speaking about Agrippa's refurbishing of the water system, Frontinus says that Agrippa, "with unique forethought provided the city with a large number of fountains" (Front. I. 9). This is said to occur at the same time as Agrippa's restoration of the Tepula. Frontinus is extremely enigmatic here, and he never specifically says why Agrippa's program of building the 500 lacus was so ingenious — after all, he states earlier that the city already had a plentiful supply of water, and that these were still highly regarded. Therefore, he cannot be referring to any pragmatic need for the lacus, since there most certainly was none. One might think that he is referring to the eventual building of the Claudia and Anio Novus, but he himself admits that these two served primarily to bring water to public works, and Evans' statistics show us that the Claudia provided 259 quinariae for public fountains, and the Anio Novus 226 (Evans 141). These figures in no way dwarf the other aquae. The Marcia, for example, provided 256 q. for lacus, the Appia 226, and the Anio Vetus 218 (Evans 140-141). Frontinus similarly could not be referring to the building of Agrippa's Aqua Virgo some 15 years later, since it only gave 51 quinariae to lacus, a mere 3.8% of the total number of quinariae used for this purpose (Evans 141). I propose that we take Frontinus' comment here as being a sort of inside comment referring to Augustus' extensive propaganda program. This idea may seem far-fetched, but logic does support it. According to Frontinus, Agrippa built the 500 lacus in 33 B.C, the same year he restored the Tepula. At this point in time, Augustus still went by his true name, Octavian, and still operated under the guise of being one of the "board of three men for the restoration of the Republic." Perhaps the unique forethought Frontinus refers to here relates to the fact that six years later Octavian would declare himself Princeps [FN 6] and would become the first Emperor of Rome. Perhaps therefore it was with this goal in mind that Agrippa built the lacus; since he knew they would be useful in the propaganda campaigns of Augustus.

The final discussion I will pursue regarding the aqueducts is their representations on Roman coins. Though these are admittedly few, they still provide great insight into how the aqueducts were meant to affect the people of Rome. In his book Monumental Coins, Marvin Temeanko describes four coins minted in the city of Rome which feature depictions of aqueducts (Temeanko 90-93): First, a Republican As [FN 7] minted by Gaius Marcius Censorinus in 88 B.C which shows two arcurationes converted into a triumphal arch, a practice which seems to have occurred occasionally (Temeanko 90-91). Also, Temeanko describes an As of Trajan, struck between 104-111 A.D, which depicts his own aqueduct, the Aqua Traiana (Temeanko 92). Third, an As of Severus Alexander circa 226 A.D which shows an aqueduct and a Nymphaeum, [FN 8] and finally, a Denarius [FN 9] of Marcius Phillipus from 56 B.C commemorating the building of the Aqua Marcia by his ancestor Marcius Rex (Temeanko 90). The most important thing to notice for our purposes is the fact that with the exception of the Phillipus coin, these are all bronze Asses, the lowest coin denomination that the Romans used. And even though the Phillipus coin is a silver Denarius, it is only the next highest denomination above an As. Although it is true that four coins can hardly be thought of as extensive and conclusive evidence, it is the only evidence we have, and it definitely supports the prior arguments of this essay. The urban poor of Rome are the societal group who would most likely handle and use an As, a coin which was of far too little value to ever be used by the rich. Indeed, none of the coins which depict aqueducts are of much value, and none appear in hordes, and so it is safe to assume that the aristocracy would probably never handle a coin with an image of an aqueduct. This evidence supports the idea that the Roman state attempted to reach the common people with their message of dependence on every level, and since the aqueducts were their primary medium for the dissemination of this message, then it makes sense that the aqueducts would appear on the coins which the propaganda's target audience would most likely handle and use — the bronze As.

I will be the first to admit that the evidence I have presented in this essay is far from being conclusive. However, there is similarly little evidence available to disclaim my arguments, and I believe I have presented my point to the best of my ability and resources, and have made a strong case for the aqueducts as a medium of propaganda. The trends we have examined and discussed in the shifts of building techniques, construction and decoration of aqueducts and public fountains, and the scanty available numismatic evidence all support the conclusion that the aqueducts were indeed a means employed by the Julio-Claudian Emperors to propagandize the masses. These commoners, who had not the education or artistic literacy to understand the subtle and cunning propaganda systems in other mediums such as sculpture, painting, or literature, were targeted instead on the level of their basic necessities. Through the pervasive and ostentatious display of the aqueducts from the time of Augustus onward, the people of Rome were made to feel as if their survival depended on the generosity of the Emperor, though we have shown that it realistically did not, on account of the numerous other options available to citizens for acquiring water. Nevertheless, the common people accepted, it would seem, the early Emperors' bids to replace the Republican ideal of the citizen who has an active interest in the endeavors of the state with the Imperial illusion of complete dependency. The Julio-Claudians, through the message of the aqueducts, made every Roman citizen out to be dependent upon them for survival, thus making it easier for the average citizen to swallow his loss of freedom and accept a monarch's wishes and interests rather than his own.





1 A digit is, as Frontinus tells us, 1/16 of a Roman foot. A Roman foot is equal to about 11.6 inches (Front. I. 24). Herschel divines that the ratio Vitrivius is giving regarding the lead pipes is twelve pounds per inch in circumference (Herschel 161). [Return to text]

2 The main sewer of Rome, which was first used to drain the area of the Forum Romanum. The second king of Rome, the Sabine Numa Pompilius (715-672 B.C) is credited with its construction, though this is probably not accurate. If the Cloaca Maxima did exist in the 8th-7th centuries B.C, it was most likely only a crude canal for drainage. [Return to text]

3 The standard unit used to describe the capacity of each aqueduct. It was a measure of how much water would flow through a pipe of 1.25 digits in about twenty-four hours. However, it is a very vague figure. Herschel puts it at "about 5000 or 6000 gallons per day, plus or minus 2000 or 3000 gallons per day according to circumstances" (Herschel 16). [Return to text]

4 A public spectacle which involved creating an artificial lake, and having fleets of ships commanded by prisoners of war engage in a sea battle, usually recreating a specific historic event. Augustus supposedly held a Naumachia recreating the battle of Actium. [Return to text]

5 "In the name of Caesar." Frontinus uses this term to describe the condition of those friends of the Emperor who were given special rights to receive water from the aqueducts free of charge and for private uses. Though I have not used it in its true sense here, it is nonetheless fitting, since the Emperor paid for the construction and maintenance of the aqueducts, and they were forever a free public service. [Return to text]

6 "First citizen." One of the many ambiguously monarchical titles Octavian held. [Return to text]

7 A bronze coin, and also the lowest value which the Romans used. In the time of Augustus, 400 Asses would be worth 1 gold Aureus. [Return to text]

8 A lavishly decorated, ornate fountain. It probably received its name from the fact that the Romans considered natural springs to be the dwelling places of Nymphae (nymphs). [Return to text]

9 A silver coin, worth 10 Asses in 88 B.C, and worth 16 Asses in the time of Augustus. [Return to text]





Evans, Harry B. Water Distribution in Ancient Rome. 1994. Ann Arbor: University of Michigan Press.

Frontinus, Sextus Iulius, trans. Charles E. Bennet (Loeb edition). De Aquis Urbis Romae. Mary B. McElwain ed. 1961. Cambridge: Harvard University Press.

Herschel, Clemens. Water Supply of the City of Rome. 1973. Boston: New England Water Works Association.

Humphrey, John W. and John P. Oleson and Andrew N. Sherwood ed. Greek and Roman Technology: A Sourcebook. 1998. New York: Routledge.

Pliny, trans. John P. Oleson. Historia Naturalis. XXXI. 38-39, XXXVI. 121-123. Greek and Roman Technology: A Sourcebook. pp. 288, 298. 1998. New York: Routledge.

Temeanko, Marvin. Monumental Coins. 1999. Iola: Krause Publications.

Vitruvius, trans. Frank Granger. De Architectura. 1931. Cambridge: Harvard University Press.


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