This ancient roman sewer is protected by a goddess!
Strolling along the Tiber River in Rome, you could be forgiven for missing this wastewater wonder of the ancient world.
While there were many strollers and joggers along the neatly paved banks of the ancient river, my husband and I were bee-lining for our next stop on our Rome itinerary: Cloaca Maxima.
What is Cloaca Maxima?
Cloaca Maxima is a large diameter drain built in Ancient Roman times in the 6th century BC. The drainage structure was named after Cloacina, an ancient Roman deity that represented purification. A shrine to this deity was said to be near the original stream, which is said to be the inspiration for the name. The literal translation in Latin is ‘Greatest Sewer’.
The design and construction
It was initially a stream that was lined with stone, aimed at draining the local marshes and removing waste from the city. By the 3rd century BC, it was enclosed with a stone barrel (semi-circular) vault so that the swampy land around the Roman sewers could be filled in.
Figure 1 Catchment area map created in 1886 of Cloaca Maxima in Ancient Augustan Rome (source: https://www.wikiwand.com/en/Cloaca_Maxima#Media/File:Roma_Plan.jpg)
The sewer was said to be dimensions that allowed inspection boats and boats fully laden with hay to pass through.
This post goes into more detail about the construction and history of the famous sewer for those that are keen to learn more: https://www.wikiwand.com/en/Cloaca_Maxima
Cloaca Maxima today
Today, the sewer is still in use, though nothing more than a trickle comes out of the once ‘Greatest Sewer’, most likely groundwater, as the city’s sewage has been long diverted to more modern pipe systems.
If you are looking to replicate this enviable photo opportunity, you can find Cloaca Maxima still visible where it joins the Tiber River near the Ponte Rotto and Ponte Palatino bridges.
Lessons from the Ancient Romans
Whilst the sewer is still technically in operation today, its much-diminished role is reportedly due to the misuse of the sewer (people putting all sorts of solid waste down there, even some political execution victims!) and backflow from the Tiber. Over time the once ‘greatest sewer’ has been re-routed to more the modern sewer system that sends sewage to treatment plants for treatment before discharge.
It’s certainly interesting to see and learn about the challenges of legacy wastewater infrastructure. Design challenges such as back flow design can be accounted for with careful planning. Social challenges with sewer misuse can be accounted for with meaningful community awareness campaigns. Either way, engineers today are working to deal with similar challenges today, just manifested with a modern twist.