By Kathleen Lusk Brooke and Zoe G. Quinn
A Culture of Water
The Romans loved water. Eleven aqueducts serving the city supplied over 1.5 million cubic yards (1.1 cubic meters) of water per day. That’s about 200 gallons (750 liters) per person, per day. Compare this to the 1975 average per capita consumption of water in the United States of 150 gallons (563 liters). But wait, there’s more. In ancient Rome, there was enough left for thousands of fountains throughout the city.
Ever wonder by the pope is called the pontiff? Water was so important that only the pope himself could order a bridge built. That’s the origin of the word, “pontiff,” which comes from Latin pontifex – bridge maker.
Danger Stimulates Innovation
Like many cities before it, Rome was built on a river, in this case, the Tiber. At its best, the Tiber was muddy. It became murkier when Rome designed its first sewer, the Cloaca Maxima, to which the Tiber River was the repository. As one might imagine, it was not long before the need for clean water became a growing problem.
But it was danger and fear that finally prompted a solution to the deteriorating potability of the Tiber. During the Second Samnite War (326-304BCE), the water supply for Rome became vulnerable to poisoning by the enemy, and so the government took action.
Setting out to find springs in the hills surrounding Rome, engineers used a few ingenious tricks. According to Vitruvius, a Roman engineer who wrote 10 books on architecture and building, scouts looked for villages whose inhabitants had particularly clear skin. Clean water, clear skin. Springs from those villages were tapped for Roman consumption. Another method: observers were to lie down on the ground in the morning and look for moisture in the rising mist. Vitruvius leaves nothing to chance; he even suggests the most convenient position for observation: chin resting on hands. Another search method developed as scouts interacted with the locals: asking the children scampering along the mountains and valleys was a sure way to find springs. One of the prized of the waters of Rome, Aqua Virgo, was named after a little girl who led surveyors to a lovely fresh water source.
Romans spoke of water the way oenophiles wax poetic about regions and vintages. The Aqua Marcia, the favorite aqueduct of many Romans, was described as fine nectar. Have we come full circle when today’s gourmet grocery shelves display waters from around the world, priced not unlike wines?
Built by the Roman army, the aqueducts were a marvel both of engineering and of organization. Work camps were established up and down the construction route from spring source to city, sometimes the route stretched as far as 60 miles (100 kilometers). When a route came through a town, locals were hired as supplemental workers. The work-camp method allowed construction to be tested along the route.
Every 20 yards, shafts were built, usually made of stone to withstand the force of the water. Sometimes wood was used as reinforcement, particularly in marshy patches. On occasion, arches were needed. Although the Romans were renowned for their perfection of the arch, these sections of the aqueducts tended to be the weakest part of the construction and often required patching or repair. Once the shaft, supports, and arches (if needed) were built, the whole aqueduct was lined with concrete. Vitruvius gives the formula: 1 part chalk + 2-3 parts sand + 20% water.
The secret to Rome’s great construction success was the quality of the sand – it was volcanic and known for superior strength. Can we improve upon this formula today in regions with similar volcanic materials?
Water was soon its own industry. There were water officials. There were surveyors. There were instrument builders; a groma was invented to measure angles, the dioptra was designed to take readings. When length was determined, elevation and slope calculated, the surveyor or librator could finalize the route. Then there were of course construction engineers, day laborers, and plenty of cafes and restaurants along the camp route to satisfy workers’ needs.
Finally there were water lawyers – water was so valuable that rights were disputed. Theft was common. Rich people bribed those in authority to “look the other way” while they tapped pipes to divert water into their own homes. It was called “puncturing.” Legal experts were required to adjudicate easements and rights of way. Lawyers may have handled personal injury claims when pots of sewage, which Juvenal satirizes, landed on the heads of people strolling by the insulae or tenement buildings. While Rome’s water system may have been a success, there were enough failures to spawn a parallel industry of legal intervention.
Oddly, in a city with so much water, fire was still a problem. Most residents used their homes for sleeping and went out to public baths instead. Juvenal talks about the dangers of fire. During emperor Nero’s reign, whole sections of Rome were destroyed by fire.
It is sometimes said that ancient Rome declined because of lead in the water supply. Probably not. Lead was certainly used in the pipes. An archeological dig at the end of the nineteenth century uncovered a lead pipe built to convey water to the Roman Forum; the pipe ran 5,742 feet (1,750 meters) and contained 513,130 pounds (232,752 kilograms) of lead. And there were thousands of such pipes.
But it should also be noted that Roman water had a high level of calcium, the deposits of which coated the lead pipes and probably prevented lead from leaking into the water supply. Lead seeps out in standing water, but flowing water retards the leakage. Confirmation of low levels of lead in the skeletal remains of ancient Romans (lead being traceable in bones) has now been verified by scientific tests.
Bread, Circuses, and Water
The height of water entertainment had to be the naumachia, staged naval battles on artificial lakes. The naumachia were public celebrations, similar to gladiatorial fights. When Domitian was emperor, he ordered special piping laid under the floor of the Roman Coliseum so the area could be flooded for naumachia.
But even the Coliseum proved too small for Domitian’s hobby, so he dug an artificial lake near the Tiber and surrounded it with seats from which he could view the elaborate naval staging.
Document of Authorization
Below is a translated excerpt from the edict ordering the construction of the aqueducts and applicable stipulations.
Edict of Emperor Caesar Augustus…in the name of the people of Venafrum…it shall be right and permissible…in regard to channels, conduits, sluices, and springs…have been made, built, or constructed above or below the water level for the purpose of building or repairing the aqueducts; or in regard to any other work which as been performed above or below the water level for the purpose of building or repairing the said aqueduct; it is ordered that whatever of the following operations have been done in the past are to continue in effect in the same manner, and workmen are to remake, to replace, to restore, or to repair in the same manner regardless of the number of times, and are to lay culverts and pipes of all sizes, to make openings therein, and to do any other work necessary to construct the aqueduct. There shall be no destruction or removal, however, of that wall or any part of that wall whereby any tract or field has been enclosed on the estate, which is, or is said to be, the property of Quintus Sirinius, son of Lucius, of the tribe Terentia, and on the estate which is, or is said to be, the property of Lucius Pompeius Sulla, son of Marcus, of the tribe Terentina, through which tract or under which tract the conduits of the said aqueduct pass, except as is necessary for the repair or inspection of the conduit. No privately owned structures shall be constructed thereon, however, whereby passage, flow, or conduction of the water can be impeded.Building the World, p. 33
Even in ancient Rome, private property had to be taken into account when developing the aqueducts, as can be seen in the edict of Emperor Caesar Augustus who carefully differentiated the rights of Italy versus the rights of landowners.
Originally published by “Building the World”, University of Massachusetts Boston, under the terms of a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported license.