Aquaducts

[Sextus Roscius]

AQUEDUCTS

 

Aqueducts, these were the driving force in Roman sanitation, running water, and indeed holding up their lifestyle. Aqueducts allowed even the poorest in Roman cities to be treated to the amazing things that we today consider impossible to do 2 thousand years ago, such as flushing toilets, elaborate bath houses, and fountains. The most amazing thing is that aqueducts allowed people access to these pleasures for no charge at all. Surely aqueducts were among, if not the greatest feat of civil engineering completed by the Romans, or any culture at all. All of this came from a simple concept.

 

THE IDEA:

Aqueducts are a simple idea; you put a pipe of water leading to a city. The ancients realized this, but they had no way of pushing water along of a horizontal surface efficiently, so they had to use gravity. So as a revised idea, a slanted pipe runs to your city. Now the ancients would

[M. Porcius Cato]

This is a really great post Sextus.

 

How were the aqueducts connected to private residences? Lead pipe? If so, how did that work?

[Lacertus]

Yes, it's a great post!

 

I know else Romans used geodesy instruments for building aquaducts and roads. They were very primitive instruments but aquaducts looks very stright!

 

I may add only a couple links about aquaducts:

 

The Roman aquaducts and water systems

Roman aquaducts (with pictures)

[Nagelfar]

Interesting topic!

 

One thing kind of puzzles me. Probably the answer is well known to the scholars of the field. Rome has an ample supply of fresh water in the Tiber. Was the Tiber so polluted that it was necessary to make the huge investments needed in building the aqueducts? Was the supply from the aqueducts better in quality or was the water pressure an issue?

[Faustus]

Salve Omnes,

 

A couple of comments here on this, a very interesting topic; I like the way you presented it:

 

1. The Tiber was the lowest grade in the terrain; all water from it would have to be lifted in some way. Typically a small stream's gradient is about 1% or 1 foot per hundred feet. This would be a stream draining only about 200 acres. But a river draining many square miles would find baseline of a much flatter gradient. For instance in Indiana in the midwest USA) a river's gradient is only about 1.0 ft per mile, so you can readily see you must go pretty far upstream to get high enough to take advantage of a water supply without "lifting" it.

 

2. As much as we hear about the ignorance of the Ancients as to sanitation, you can be sure they would not drink polluted water; consider the repellent quality of a moat around a medieval "Castra". The only water of any quality at all would have been upstream from Rome, and again would have to have been lifted (bailed? pumped? bailed and hauled in barrells?)

 

3. Pipes were made of hollowed out sections of wood not stone, though I understand "stone" implied "aquaducting" as a method of "piping" water. I don't know how wood (trees? were hollowed out but I have read that that they were and I'm sure I can relocate the source. The wood swells sealing the hub joints. These would be used for the final tributaries to the system, or what we would call

[Klingan]

Great post but I have some questions and futher thoughts.

 

SANITATION:

Of course, they knew what it was, they knew the idea, they knew what it had to be, but then the problem came of sanitation. In order to keep the water sanitary, the put the pipe line along arches, this also allowed them to make it slanted without digging into the earth deeper and having to pump the water up to get it. As an additional way to stop contamination, they also added a stone roof to the pipe line, in order to keep things from coming in from the top. This made the water as sanitary as possible before arriving to the reservoir in the destination. This was clearly effective, because anyone wanting to contaminate the water would have to climb up the structure, remove a heavy stone at a high altitude, and the do something with what ever they managed to bring up there. This all kept the aqueducts, and more importantly the water in them sanitary.

 

Actually the reason why we see aqueducts like this today is just beacuse they are much more visable then the huge main system. about 80-90% are built underground about 0.5-1 meter down. As far as ever possible they tried to keep it like this with service enteries roughly every 75th meter. However they had another rather unknown sanitary effekt: Very muhc of the water were flowing out from fountains and all kind of places. Once you ahve your pipe it's in just about all cases impossible to stop the water. Therefor it must have been effectivly cleaning the cities constantly, or atleast been keeping away the worst dirt in certain areas.

 

 

Nagelfar, for the first hundred of years they were drinkign from the Tibern, surly not very healty from our perspective but they survived it. The first aquaduct were built (According to Frontinus in the 441st year after the city was founded so before that it was just the Romans and the Tiber river. The pressure is more like a bonus effect. The reasons to build them were proboably to get water to people as they built their houses further away from the river as the city grew. I must have been problematic to carry all the water not to mention how crowded it must have been.

 

For the last section of the watersystem inside the cities they used lead pipes, wooden pipes as Faustus describe or terracotta pipes but those were more popular in the east.

 

Faustus: By some reason were they (To my knowlege) not a common military target but it may be linked to that the main bulk was not visible. They would be expensive to repair too if you were succesfull in your seige. The aquaduct in Pompeii isn't visible before the cictern that's placed in the highest part of the city, they had problems with too high pressure in the other end of the town and had to built repressurizing towers!

 

However they were used as escape tunnels during seiges. All aqueducs were built to make sure that a slave easily could fit inside for maintaince work (Cleaning sediments etc)

 

Does anyone have good information on the inside the city water systems? I'm interested in anything you've got!

[Maladict]

There are also a number of natural springs inside the city.

In times of siege the population could rely on them, just like they probably did in pre-aqueduct times.

[Gaius Octavius]

Wooden pipes are still in use in New York City.

 

The Roman engineers tunneled through mountains to get the water to cities in as much of a straight line as possible.

I think that there were cross strips every few feet at the bottom of the 'pipe' to prevent clogging.

The homes of the rich were serviced directly and they were taxed for this service.

Edited October 2, 2007 by Gaius Octavius

[Nagelfar]

Thanks for the interesting thoughts on this issue!

 

The pollution (water quality) and the distribution aspects are as you say important.

 

Still, it should be feasible to raise water from the Tiber, but I guess that the capacity would be nothing like the gravity based aqueducts. Considering the huge investment in capital that was required to build the aqueducts, and think of alternative systems. You could probably have many slaves or oxen occupied to raise water to match the building costs. Now, there are huge economies of scale in the aqueducts, so the volume of water needed probably plays into the equation.

 

Further, I guess the aqueducts were monumental constructions to glorify their "builders".

[Klingan]

Yeah the monumental part is clearly important and so are the building of the baths. I guess they were necessary during the late republic/imperial age thou since everything was flowing down into the Tibern. They say that you could smell Rome days from the actual city.

 

Go; Actually we know of places where the romans choose to build their aqueducts turning and twisting to add to their length and therefor allow a lower slope for the water. A too high slope is unacceptable. Normally it's somewhere between 1 meter and 7 millimeter per kilometer in length.

 

I also forgot in my last post to mention leather pipes.

 

By the way does anyone know how the romans cleaned their smaller pipes? They range between 2.5 cm to 5 cm approximately. The sediments should block them real quickly otherwise.

[Gaius Octavius]

Go; Actually we know of places where the romans choose to build their aqueducts turning and twisting to add to their length and therefor allow a lower slope for the water. A too high slope is unacceptable. Normally it's somewhere between 1 meter and 7 millimeter per kilometer in length.

 

I thought that they used towers and cisterns to take care of big drops.

[CiceroD]

The pollution (water quality) and the distribution aspects are as you say important.

 

Still, it should be feasible to raise water from the Tiber, but I guess that the capacity would be nothing like the gravity based aqueducts. Considering the huge investment in capital that was required to build the aqueducts, and think of alternative systems. You could probably have many slaves or oxen occupied to raise water to match the building costs. Now, there are huge economies of scale in the aqueducts, so the volume of water needed probably plays into the equation.

 

Speaking as a Boy Scout who has had "purified" river water it is ABSOLUTELY wretched

Do we have any evidence that they really ever drank from the Tiber? I really can't believe that they would do it. Isn't the Tiber silty even if it wasn't polluted?

 

My often quoted copy of "The Ancient City" by Connoly and Dodge states that before the Aqua Appia, the first aquaduct, The Romans relied on springs, wells, and cisterns built into their houses' impluvia.

[Klingan]

Go; Actually we know of places where the romans choose to build their aqueducts turning and twisting to add to their length and therefor allow a lower slope for the water. A too high slope is unacceptable. Normally it's somewhere between 1 meter and 7 millimeter per kilometer in length.

 

I thought that they used towers and cisterns to take care of big drops.

 

They had step constructions at some places and obviously they did use towers and cisterns in the cities to gather the water, but when out in the country they tried to avoid it. I guess it's because of the terrible wear it would have on the aqueduct. Since a cistern was supposed to hold a lot of water at the bottom it was fairly protected. Aqueducts were only filled up 1/3 or so, resulting in that they would create an artificial waterfall if using a tower (Or cistern) mid way. I have seen a sort of junction cisterns midway to connect several aqueducts in Germany thou (K

[ASCLEPIADES]

Salve, Amici!