Someone once wrote that good Game Masters seem to know a little bit about everything. If it’s not obvious, this is because they need to know how the world works so they can make their own game settings seem real. I know this first-hand from years of running fantasy campaigns. At one point or another, I found myself digging into the details of agriculture, mining, free diving, sailing, carpentry, sheep breeding, the wool trade, and a dozen other subjects that I never imagined I would research. Of course, this is not limited to fantasy role-playing. When running Gamma World or some other apocalyptic game, a good GM probably needs to know a little about modern firearms, lasers, nuclear radiation, mutation, the ecology of a wasteland, etc. Running Traveller or another sci-fi game, the GM should probably know something about the vacuum of space, space travel, planets, stars, asteroids, comets, gravity, etc. You get the idea.
Not long ago, M.J. Young of the Christian Gamers Guild penned a few short articles on very generic topics, like waterways, country roads, and cities. Though at face value they seem too generic to be helpful, the articles can be surprisingly useful to GMs. Great GMs might know a little about everything, but they don’t start off like that. Everyone needs to pick up basics from someplace, and MJ’s articles were great for anyone not already knowledgeable about those topics. Even veterans can glean some points that they had never considered.
In this brief article, I‘ll touch on another topic that seems like it could be useful to many GMs—sewers. I cannot count the times that I’ve seen modules or homemade adventures with wererats skulking through labyrinthine sewers. Strangely, though I’ve been playing for over thirty-five years, I never played in or ran such an adventure. I recently decided to add a sewer setting to an ongoing campaign, but I realized that I had to find out something about sewers first. As with most things, one topic connects to many others. In this case, I found it tough to examine sewer systems without simultaneously looking at water supplies and plumbing.
First, the basics: People need water to live. They need it to drink, they need it to irrigate crops, they often need it to cook, and, when living together in significant numbers, they need it for sanitation. Depending on the environment and the amount of work one must do, dehydration can kill within days. Likewise, poor waste management, especially in a crowded town or city, can lead to epidemics that lay waste to entire regions. Thus, early civilizations quickly realized the need for fresh water sources, for ways to move water within their settlement, and for ways to get rid of it.
A survey on the development of water management and sanitation in ancient societies, though by no means comprehensive, should give us some sense of how long ago certain features were developed.1 That will give GMs some idea of what might be available in their various game-world civilizations—at least if they wish to base them (however roughly) on historical precedents. When I first learned of these developments, I was rather surprised that so many ‘modern’ features are actually ancient.
Around 4000 BC in Mesopotamia, the Sumerians of the city-states of Nippur and Eshnunna seem to have been the first to develop clay pipes to move water. Sometime between 4000 BC and 2500 BC, various cities in Mesopotamia showed signs of using surface ditches to move excess water, like those produced by heavy rains during storms. Between 3200 BC and 2300 BC, the ancient Minoans on the island of Crete made great strides with water management. The palace at Knossos featured stone conduits (pipes) that led storm water (meaning fresh water from rain, as compared to waste water) away from the palace to prevent flooding. That same palace, built on a hillside, also featured several stone conduits that ran downhill and carried away waste. Smaller conduits, often made of terracotta (hardened clay, like the flower pots), measuring 4” to 6” in diameter, led into the larger stone conduits. Meanwhile, rainwater from the roofs collected into large stone cisterns. Excess water in the cisterns could be funneled into drainpipes or into sewer pipes to flush them. Most impressive was the development of the earliest known flush toilet, dating to around 1700 BC! Rainwater from the roof or water from cisterns in the walls carried away waste, flushing it down one of the stone sewer conduits in the palace.
A brief aside on cisterns and wells is probably in order here before moving on. A cistern is just a waterproof receptacle, used to store water. They are commonly used where fresh water is difficult to obtain by means of a well or by access to a waterway, making the collection of rainwater a better alternative. A cistern could be small or vast. Many ancient cisterns in the Middle East were pear-shaped, about 15’-20’ deep, with a 2’-3’ wide opening and a stone cover. Small cisterns were often privately owned, while large ones often stored water for the whole community (or a large segment of it). Many ancients waterproofed the sides of cisterns with clay or with lime plaster. The largest cisterns were cavernous spaces, carved from solid rock. Many archaeologists consider the Hellenic period to be the height of cistern development because several large cities throughout Greece were entirely dependent on rainwater for their water supply. Cisterns were sometimes located in buildings, where they were fed by rainwater from the rooftops. Cisterns were often built into hillsides, where gravity could easily funnel runoff (rainwater that does not soak into the ground but instead runs downhill) into the openings. The openings were often covered to keep out debris and other contaminants. In time, cracks often developed in a cistern’s walls, and it would leak.
Cisterns could enable settlements to withstand a siege for some time, even in dry and dusty places. King Herod’s royal fortress at Masada in ancient Israel was considered impervious to siege because of the massive cisterns there (the main reason why the Romans had to assault its walls circa 73 AD). The massive cisterns at Masada held over one million gallons of water—enough to supply drinking water for the inhabitants, for several swimming pools, and for an entire bath complex—all in the middle of the parched Judaean Desert!2
Lastly, empty cisterns sometimes served as prisons, underground chambers, hideouts, meeting places, and places of burial.
Unlike a cistern, which simply stores water, a well taps into existing groundwater, such as a natural spring or underground stream. To make a well, ancient and medieval workmen usually had to dig into the earth by hand. It could be incredibly time-consuming, depending upon the rockiness of the soil and on the depth of the groundwater. Workmen usually lined the sides of the well with stones to keep them from collapsing. The openings were often capped or covered to prevent accidents and contamination. A well was often the most important feature of a castle (unless it had cisterns). Without a fresh water supply, even the most stalwart garrison could not hold out for long. Knowing this, those attacking a castle often gave a thought to contaminating the castle’s well somehow, perhaps with an animal carcass. Far more often, however, defenders poisoned their own wells while withdrawing before an invading army.
Around 2350 BC, in the Indus River Valley of India, the city of Lothal featured many houses with private toilets, each of which was connected to a terracotta sewer line, complete with wooden screens to hold back solids. These emptied into either local bodies of water or cesspits, which workers routinely cleaned.3
By 2100 BC, Minoan towns and cities on the island of Crete had sewers connecting the houses. By 1800 BC, Minoans on Crete and on the island of Thera (modern Santorini) had some water-flushed toilets.4
Around 1200 BC, ancient Egyptians, for all of their impressive knowledge and wealth, were still using toilets that were essentially stone containers filled with sand, which slaves then emptied (I cannot help but think of a litter box).5
Sometime between 1200 BC and 700 BC, the ancient Hittites in their capital city of Hattusas in central Anatolia (modern Turkey), developed segmented, detachable, terracotta pipes. One end of each segment was a bit narrower, while the other end was a bit wider, allowing each segment to fit into the next. These detachable segments made cleaning and replacement easy.
Between 1046 BC and 256 BC, during the reign of the long-lasting Zhou Dynasty, the Chinese developed sewers in several cities, such as their capital of Yingqiu (or Linzi).6
As early as 1000 BC, the Persians developed a system of qanats to move water down a hillside. They first dug vertical access shafts down into the water table. From these, they dug narrow, underground, diagonal channels down the hillside, which carried water to homes or to fields.7
By 900 BC, Greeks on the legendary island of Delos featured toilets flushed by either rainwater or by water directed from cisterns. They too used gravity to do the trick, as most houses sat upon hillsides.8
Sometime between 700 BC and 400 AD, the Romans developed a very advanced and comprehensive system for water and sanitation in Rome. According to tradition, the sewer system beneath Rome, called the ‘Greatest Sewer’ (Cloaca Maxima), dates to 600 BC, but the Romans improved upon the system over the centuries. Rome was also known for its public fountains, public bathhouses, public latrines, and flush toilets, all of which required large quantities of water. It is said that Rome boasted one thousand public bathhouses during Imperial times. Some bathhouses (balneae) were modest in size, while others (therma) were the lavish meeting places of the rich and famous.9
To increase the flow of water to the city, the Romans built the city’s first aqueduct in 312 BC (the Aqua Appia), a second in 272 BC (the Aqua Anio Vetus), and a third in 145 BC (the Aquia Marcia). Constant battlefield victories led to the expansion of the city and a need for even more water, leading the Romans to build a fourth aqueduct in 127 BC (the Aquia Tepula) and a fifth in 33 BC (the Aqua Julia). The Emperor Augustus added yet another in 19 BC (the Aqua Virgo) and another in 2 BC (the Aqua Alsietina), the latter of which could create an artificial lake to entertain the populace with sea battles. In 38 AD, the Emperor Caligula began two more aqueducts, but his successor, Claudius, completed them. The Romans finished both in 52 AD (the Aqua Claudia and the Aqua Anio Novus). By the close of first century AD, eleven aqueducts supplied Rome with water.
A brief aside on aqueducts: The Romans used raised stone channels called aqueducts to carry water from the outlying hills to the city. Water from natural lakes was diverted to these waterways. Where natural lakes did not exist, the Romans built dams to create them. The stone channels sat upon a sturdy but elegant system of stone arches. Though they appear level, they had a slight but even grade so that gravity would bring the water to the city. These impressive structures spanned valleys, chasms, and rivers.
The Romans clearly borrowed many ideas from civilizations around them, and they also invested heavily in their city’s sanitation and water systems. In fact, historians and engineers often cite the sewers of late Imperial Rome as the most advanced in the ancient world. What about the medieval period? Unfortunately, during the Middle Ages, the rulers of Rome neglected the city’s sewers rather than expanding them. Looking elsewhere, we see that the government of medieval Paris began creating a sewer system there in the 14th century, but it was not until the 19th century that the Paris sewers became the labyrinth that features in several works of literature. Thus, it makes sense for GMs to take a closer look at the sewers in Rome. Sewers in fantasy games are almost always more spacious and complicated that historical ones, but knowing what was possible will give us a solid foundation on which to build. If your game setting is ancient, then you’ll have a direct correlation. If it is medieval or early modern, then you’ll know what an ancient and ruined sewer system in your world might look like.
Rome’s famous sewer system, the Cloaca Maxima, supposedly dates to the beginning of the seventh century BC. The legendary Etruscan king, Tarquinius Priscus (616-579 BC) is said to have ordered its construction around 600 BC.10 One might logically presume that the ruler of Rome built the sewer system to carry waste away from the city—a sure sign of progress over the use of cesspits and chamber pots, which were typical at the time. However, only later did the sewer serve to carry away human waste. Its primary function was to control the flow of water through the city. Ancient sources say that King Tarquinius built the Cloaca to drain the marshy ground at the foot of three of Rome’s seven hills. Streams regularly ran southwest from the Quirinal, Viminal, and Esquiline Hills into the low-lying flatland east of the Capitoline Hill. Romans writers explain that the area was so wet that the Romans could float small boats there. King Tarquin had workers wall off the streams, channeling them into one open-air ditch that carried water southwest. Initially, it stretched little more than 100 meters, but decades later, the Romans extended this channel further, between the Capitoline and Palatine Hills (an area known as the Velabrum) and out to the Tiber. For reference, as the crow flies, that is about 10,000 feet long—almost two miles in length. When using map squares or dungeon tiles that represent 10’, you have a sewer system that is potentially 1000 squares long! A German engineer named Merckel, writing in 1899, gave the length of the primary channel as 1742 feet (or 174 map squares in gaming terms).11 At the very least, the original 100-meter stretch equals about 32 map squares.
The Roman historian, Livy, writing centuries after the fact, notes that Etruscan engineers built the canal using large numbers of laborers (sometimes forced) from the poor classes of Rome.12 In fact, another historian, Pliny the Elder, described the work as so grueling that laborers turned to mutiny or even suicide to escape the work. Indeed, the king had the bodies of suicides crucified at the site to discourage further mutinies.13 Though later Roman writers mention the sewers as being underground, the Roman poet Plautus (circa 254-184 BC) described it as an open ditch, suggesting that it was not covered until after his time.
What did these Roman sewers look like once fully developed? Well, we already know their approximate length. The heavy stone blocks that lined the main channel itself were about 4’x4’x1’. They were simply fitted together, meaning that no concrete was used. A benefit of the heavy stones was stability. Pliny wrote that even occasional earthquakes, over the course of seven centuries, had not disrupted the channels. Though stability is good, a close look at other ancient canals in Italy and beyond demonstrates that such large blocks were probably unnecessary. However, the Etruscan kings responsible for the construction of the Cloaca likely wanted to commemorate their engineering achievement—especially given the importance of the project. This is a reasonable assumption, as many ancient monarchs purposely built for the ages, making sure that engraved stone markers along the way gave them full credit for the work. Thus, a fantasy sewer system might well have large marker stones with ancient inscriptions that honor old kings or emperors.
We also know that the Romans eventually covered the stone-lined channels with a barrel vault (semi-circular arch) of stone. A single layer of fitted tuff voussoirs (tuff is a brown or gray volcanic stone, and a voussoir is a wedge-shaped block used in making arches) formed the vault over most of the primary channel. However, about 40’ from the outfall (where it opened into the Tiber), two additional layers of pepperino stone were laid atop the initial vault. Each hewn stone block of the barrel vault was roughly twelve inches high and twenty-three inches long.
At its widest point, the main channel of the Cloaca was over ten feet wide.14 One Roman historian noted that maintenance workers could ride a hay wagon down the channel, and another two noted that an official, after ordering the sewers to be cleaned, passed through the channel by boat (perhaps on an inspection).15 As for height, the main channel was twelve feet, four inches high, but, over the centuries, about eight feet of mud has filled the channel.16 It is difficult to determine how deep below ground the main channel lay. One work asserts that the foundations were built forty feet underground. This seems reasonable, as the swampy area that they meant to drain once sat below sea level, and the Romans built up the area with gravel to about thirty feet above sea level.17
If we imagine the primary canal twisting like a covered snake and running from the base of the three hills to the Tiber, we must now imagine scores of smaller culverts (underground channels or pipes) that ran perpendicularly into the main channel. Sewer pipes were often terracotta. If a pipe had to withstand pressure, the Romans usually embedded it in concrete.18 The secondary culverts initially funneled storm water (as compared to waste water, or grey water).
Only near the end of the first century did wealthy Romans begin connecting their private homes to the system. Odors were a problem, especially because there were few vents. Indeed, connecting one’s house to the sewer system essentially made one’s house into a vent for entire system.19 Many wealthy Roman families originally opted not to connect their homes to the city’s system, partially because of the stench and also for fear of sewage backing up into the house. There were two additional concerns as well—concerns that all Romans had when visiting public latrines. First, rats sometimes emerged from the culverts to surprise those trying to relieve themselves. Stranger, the buildup of methane gas occasionally caused minor explosions that sent flame up the pipes and out of the latrine seats!20 Fittingly, Romans used graffiti both to warn of demons in the latrines and to invoke the protections of the Goddess Fortuna. For some comedy relief in your games, throw some graffiti in your fantasy sewers. If you are feeling wicked, consider placing a fire mephit or some other minor fire demon in the sewers, along with the ubiquitous rats.
To the initial sewer system (the Cloaca and its secondary or feeder culverts), the Romans eventually added two others—the Campus Martius (Field of Mars) system and the Circus Maximus (Great Circus) system. Each featured scores of small culverts that fed into the larger primary channels. As a rule of thumb, Roman engineers usually laid large primary channels along valleys between hills, allowing gravity to carry water and sewage toward a river, while smaller secondary culverts fed into primary ones.
The sewer lines seldom ran in straight lines, though one would imagine this to be the easiest design. One must recall that the system was built in stages, adapting to the needs of a growing city. Also, the Roman engineers, fearful of collapse, rarely built large structures over the main channels. Instead, they directed new channels around new construction, which explains the sewers’ many twists and turns. It also explains why many lines, having fallen into disuse, were sealed off. When designing a large ancient sewer system, GMs should feel free to throw in plenty of dead ends.
Roman engineers tended to make repairs only on sections that broke or became outdated. Thus, the entire system was a patchwork. Stone supplies from local quarries sometimes ran out, requiring the engineers to find new sources further abroad. In the Cloaca, one can find areas made with blocks of Gabine stone, others made with blocks of tuff or travertine, and even a section made entirely of concrete.21 Construction techniques also differed over the centuries. Following suit, stonework in fantasy sewers may be noticeably different from section to section. To add a bit of flavor, GMs might note that the limestone walls in one area give way to smaller blocks of basalt or granite in another. Likewise, barrel vaults over the primary channel may be common in the older sections, while newer sections might feature groin vaults. Likewise, small culverts might serve as secondary channels in older sections, whereas wider secondary channels might exist in newer sections. In a fantasy campaign, dwarves and the like might notice such changing techniques, allowing them to date the work to some degree.
The ancient Romans levied a special tax (cloacarioum) to finance the maintenance of the sewers. During the Republic, the censors oversaw this maintenance, but during the Imperial period, special administrators (cloacarum curators) took on the role. Workmen could divert water from the aqueducts or bathhouses to flush the main channels, but they frequently had to clear debris and other blockages (corpses, animal carcasses, etc.) by hand. I’m not entirely sure what the hay wagons (noted by Strabo) were for, but perhaps workers used them to remove said debris. Modern archaeology suggests that the accumulation of simple sediment likely posed a continual problem, requiring Roman workers to routinely clear it.22 In addition to entering the system horizontally, workers could also access the system vertically through stone manhole covers. In these locations, stone steps led down to the main channel. In the tunnels themselves, workmen could use narrow ledges on the sides of the channel to avoid the muck. As the system itself was seldom uniform, the ledges are wider in some areas, narrower in others, and altogether missing in still others.
I would be remiss if I failed to mention that the Latin word for drain (cloaca) derives from the name of the Etruscan goddess, Cloacina (the ‘Cleanser’). She protected the sewers, along with sexual intercourse in marriage. The Romans later identified her with Venus (Venus Cloacina, or Venus the Cleanser). In a fantasy sewer, workmen might have transformed an abandoned, subterranean chamber into a shrine to the goddess Fortuna or to the goddess Cloacina (or perhaps the equivalents in your campaign setting).
In conclusion, while considering the sewers of Imperial Rome as the best historical model on which to build, we see that the system was extensive, built to last, and a bit more spacious than one might think. Though fantasy sewers tend to be more spacious still, they are not a far cry from the Roman one. In worlds filled with magic, with large creatures (like ogres and giants), and with creatures especially adept at mining (dwarves, gnomes, etc.), it seems perfectly reasonable to imagine sewers like those beneath the fantasy cities of Waterdeep and Lankhmar.
If you have not yet used sewers in your game, I suggest that you try it. They can bring a crop of new challenges—water hazards, vermin, bad footing, swirling mists, disease, parasites, repulsive smells, occasional explosions, foul creatures (an otyugh or even a methane fire mephit), comical graffiti, ancient shrines, crumbling stonework, tight spaces where combat is difficult, restless dead emerging from adjacent catacombs, thieves meeting in secret, and cultists worshiping some ancient horror that lurks in the dark tunnels. Throw in a lost treasure, and it screams adventure.
Livy published his Ab Urbe Condita Libri (Books from the Foundations of the City) circa 9 BC. He mentions the Cloaca in 1.38.6 and 1.56.2.
Marcus Vitruvius Pollio, a Roman architect-engineer, gives a thorough description of bath design and construction in De Architectura, his treatise on architecture, published circa 15 BC.
Dionysius of Halicarnassus, writing in the early Empire, published his Roman Antiquities, sometime after 7 BC. He mentions the Cloaca in 3.67.5 and 4.44.1.
Strabo finished publishing his Geographica (Geography) sometime around 23 AD. He mentions the Cloaca in 5.3.8.
Pliny the Elder published his Naturalis Historia (Natural History) circa 77 AD. He mentions the Cloaca in 36.24.
Lucius Cassius Dio published his 80-volume Historia Romana (Roman History) circa 229 AD. He mentions the Cloaca in 49.43.
SELECT SECONDARY SOURCES
Alemohammad, S.H. and S. Gharari. “Qanat: An Ancient Invention for Water Management in Iran”, found in Proceedings of Water History Conference, Delft, The Netherlands.
Angelakis, Kavoulaki, and Dialynas. “Sanitation and Wastewater Technologies in Minoan Era”. This forms Chapter 1 in A.N. Angelakis’ and J.B. Rose’s Evolution of Sanitation and Wastewater Technologies through the Centuries. London: IWA Publishing, 2014.
Antoniou, George P. et al. “Evolution of Toilets Worldwide through Millennia”, in Sustainability published by Multidisciplinary Digital Publishing Institute (MDPI) on 13 August 2016.
Blake, Marion Elizabeth. Ancient Roman Construction in Italy from the Prehistoric Period to Augustus. Washington, D.C.: Carnegie Institution of Washington, 1947.
De Feo, Giovanni et al. “The Historical Developments of Sewers Worldwide” found in the online journal called Sustainability, published by Multidisciplinary Digital Publishing Institute (MDPI) on 20 June 2014.
El-Gohary, Fatma A. “Evolution of Sanitation and Wastewater Technologies in Egypt through Centuries”. This forms Chapter 4 in A.N. Angelakis’ and J.B. Rose’s Evolution of Sanitation and Wastewater Technologies through the Centuries. London: IWA Publishing, 2014.
Hopkins, John N. N. “The Cloaca Maxima and the Monumental Manipulation of Water in Archaic Rome.” It is found in the Open Access Journal entitled The Waters of Rome: Number 4, March 2007.
Khan, Saifullah. “Sanitation and Wastewater Technologies in HarappalIndus Valley Civilization (circa 2600-1999 BC)”. This forms Chapter 2 in A.N. Angelakis’ and J.B. Rose’s Evolution of Sanitation and Wastewater Technologies through the Centuries. London: IWA Publishing, 2014.
Koloski-Ostrow, Ann Olga. The Archeology of Sanitation in Roman Italy. Chapel Hill: North Carolina Press, 2015. Accessed on JSTOR.
Langfur, Stephen. “Masada’s Water Supply”, an online article located on the NET (Near East Tourist Agency) website. Found at http://www.discoverthebiblelands.com
Merckel, C. The Engineer Technique in Antiquity. Berlin: Springer, 1899. This work is referenced by Robert S. Deiamond and Brian G. Kassel in their article “A History of the Urban Underground Tunnel (4000 BCE – 1900 CE)” in The Journal of Transportation Technologies, Vol. 8, No. 1, January 2018.
Smith, Philip. “Cloaca”, an article found in William Smith’s A Dictionary of Greek and Roman Antiquities. London: John Murray, 1875.
Tytler, Alexander Fraser. Elements of General History. London: Adam Scott, 1846.
1 There are many works that describe water management in antiquity. I used no one particular source, but one of the best that I found with regard to sewers was “The Historical Developments of Sewers Worldwide” by Giovanni De Feo et al., published in the journal called Sustainability on 20 June 2014.
2 Various sources agree that the cisterns at Masada were once quarries, from which the stone blocks from the fortress came. Also, some sources say that the cisterns held ten million gallons. Part came from rainwater, while the rest came from diverted runoff on the western side of the mountain. A dam caught the floodwater and directed it into an aqueduct, which brought it into the cisterns. For more information on the site, see Stephen Langfur’s online article, “Masada’s Water Supply”, located on the NET (Near East Tourist Agency) website.
3 Saifullah Khan, Sanitation and Wastewater Technologies in HarappalIndus Valley Civilization (circa 2600-1999 BC). This forms Chapter 2 in A.N. Angelakis’ and J.B. Rose’s Evolution of Sanitation and Wastewater Technologies through the Centuries (London: IWA Publishing, 2014), 32.
4 For more detail on Minoan Crete’s very advanced system of water management, see A.N. Angelakis’, E. Kavoulaki’s, and E.G. Dialynas’ Sanitation and Wastewater Technologies in Minoan Era. This forms Chapter 1 in A.N. Angelakis’ and J.B. Rose’s Evolution of Sanitation and Wastewater Technologies through the Centuries (London: IWA Publishing, 2014), 1-24.
5 Fatma A. El-Gohary, “Evolution of Sanitation and Wastewater Technologies in Egypt Through Centuries”. This forms Chapter 4 in A.N. Angelakis’ and J.B. Rose’s Evolution of Sanitation and Wastewater Technologies through the Centuries (London: IWA Publishing, 2014), 61-62.
6 Giovanni De Feo et al., “The Historical Developments of Sewers Worldwide”, published in the journal called Sustainability on 20 June 2014, 3943.
7 For a closer look at qanats, see a brief 2010 article by S.H. Alemohammad and S. Gharari, entitled “Qanat: An Ancient Invention for Water Management in Iran”, found in Proceedings of Water History Conference, Delft, The Netherlands.
8 George P. Antoniou et al., “Evolution of Toilets Worldwide through Millennia”, published in the journal called Sustainability on 13 August 2016.
9 A Roman architect-engineer named Marcus Vitruvius Pollio gives a thorough description of bath design and construction in De Architectura, his treatise on architecture, published circa 15 BC.
10 Of the sources that I read, the most direct and concise scholarly work on the early Cloaca Maxima was an article by John N. N. Hopkins at the University of Texas. The article, a result of his 2004 thesis, is entitled “The Cloaca Maxima and the Monumental Manipulation of Water in Archaic Rome.” It is found in Waters of Rome: Number 4, March 2007.
11 C. Merckel, The Engineer Technique in Antiquity (Berlin: Springer, 1899), 454-465. This work is referenced by Robert S. Deiamond and Brian G. Kassel in their article “A History of the Urban Underground Tunnel (4000 BCE – 1900 CE)” in The Journal of Transportation Technologies, Vol. 8, No. 1, January 2018.
12 Livy, Ab Urbe Condita Libri, 1.56, found online at perseus.uchicago.edu.
13 Pliny, Naturalis Historia, 36.24.
14 Smith, Cloaca.
15 Strabo mentions the hay wagon (Strabo 5.8), while Cassius Dio mentioned Marcus Agrippa’s subterranean voyage (Cassius Dio 49.43). Pliny seems to allude to Agrippa’s journey (Pliny 36.24). The event seems to have occurred in 33 BC according to Ann Olga Koloski-Ostrow, The Archeology of Sanitation in Roman Italy (Chapel Hill: North Carolina Press, 2015), 69. Accessed on JSTOR.
16 Smith, Cloaca.
17 Alexander Fraser Tytler, Elements of General History (London: Adam Scott, 1846), 149. J. Hopkins also seems to confirm this in “The Cloaca Maxima and the Monumental Manipulation of Water in Archaic Rome”, 10.
18 De Feo et al., Historical Developments of Sewers Worldwide, 3952.
19 De Feo et al., Historical Developments, 3952.
20 Ann Olga Koloski-Ostrow, The Archeology of Sanitation in Roman Italy, 69. Accessed on JSTOR.
21 Marion Elizabeth Blake, Ancient Roman Construction in Italy from the Prehistoric Period to Augustus (Washington, D.C.: Carnegie Institution of Washington, 1947), pp. 159-161.
22 Ann Olga Koloski-Ostrow, The Archeology of Sanitation in Roman Italy, 65. Accessed on JSTOR. The author also argues that Cloaca, while useful in moving excess storm water, did little to improve hygiene in the city, especially in the slums, where excrement and urine remained common on the streets, and flies went unchecked, leading to the frequent outbreaks and a high mortality rate.