Underground Sewers

Lore & Background

The hydrological context in which Parisians developed their sewer system over the centuries is complex. The ancient system of waterways of the Seine and of local springs resulted in a challenging situation in terms of water volume and circulation. From the Mesolithic period until the Middle Ages, a secondary branch of the Seine cut an uneven semicircle to the north of Paris, starting from what is now the Bercy neighborhood of the eastern 12th arrondissement, then passing approximately through the current Place de la Bastille and the Place de la République, then through the Saint-Lazare train station, before finally joining the main course of the Seine at roughly the site of what is now the Pont de l'Alma.

Though silt and human activity eventually filled in this secondary branch, it nevertheless formed a marshy depression in the northern part of Paris that received runoff from the hills of Belleville, Montmartre, and Roule. This runoff and the numerous natural water sources in the area fed a stream called the Menilmontant brook, which followed the course of the ancient river. This stream rose at the foot of the Ménilmontant hill before emptying into the Seine at current location of the Pont de l’ Alma.

Besides the multitude of watercourses and springs in Paris, the city's topography posed another problem: its lack of slope. With the exception of its south-southeast sector on the southern bank of the Seine, the Parisian landscape at that time ranged from 32 to 40 meters in altitude. This relatively flat topography, combined with the long distances that the sewers had to travel, 'made the average slope imperceptible', which greatly complicated the gravity flow of wastewater and explained the structural difficulties encountered when setting up the first sewer systems.

It is presumably because of the abundant supply of water and the flat terrain that the Romans assigned the name of Lutetia — meaning, according to some translations, ‘city of mud’ — to the Gallo-Roman city that preceded Paris.

Reader's Guide

For most of the Ancien Régime period, human waste removal was accomplished by means of sewers or by physical removal by specialised services. For the latter method, human waste was removed by street cleaners who were responsible for cleaning out what was thrown into the middle of the streets and by private services that emptied the pits that were dug in individual houses. This organic matter was delivered to dumps where, for a time, it was mixed with other detritus generated by the city's inhabitants.

In 1674, the city government ordered that the two types of detritus should be separated into different waste facilities. In 1758, a decree ordered that all dumps must be moved outside the city walls, with the main city dump being ultimately consolidated in Montfaucon, at the base of what is now Butte-Chaumont. In addition to this method, a mix of public and private or semi-private sewers existed. Under this system, the responsibility for building and maintaining sewers was not clearly defined, and private people sometimes took it upon themselves to clean and repair existing 'public' sewers.

During the 1700s, some clarification of responsibility for sewer construction and maintenance was made. The municipality assumed responsibility for building and maintaining sewers by paying external service providers to do the work. In 1721, the city government required that citizens must pay to clean sewers serving their houses. In 1736, it declared that any citizen caught dumping garbage into the sewers would have to pay a considerable fine and servants caught doing so would be subject to corporal punishment.

Some sewage construction also occurred during the 1700s. The royal family – the Regent and the young Louis XV – decided that they wished to take up residence in Paris and wanted to develop a new quartier to house the royal entourage. However, the chosen site was subject to the overpowering odours of the old beltway sewer. In order to solve this problem, work began in 1737 on a sewer that would ultimately incorporate several innovations (relative to other Parisian sewers).

The Provost Michel-Étienne Turgot oversaw the construction of a new sewer that contained, at its head, a reservoir of water that was used to provide a reliable source of water for flushing out the sewer as well as a series of valves that could be used to release water in a distributed manner for sewer cleaning and for fighting fires. At the completion of the new sewer in 1740, Louis XV – showing an unprecedented interest in such matters by a member of the royal family – attended the inaugural flushing of the sewer.

Despite its relatively advanced design, Turgot's sewer did not survive for long. The municipality accorded private parties the right to build over the sewer line as long as they covered it with a vaulted ceiling made of masonry. Furthermore, each individual owner had to have its section of the sewer cleaned by a service provider certified by the municipality. This did not work in a satisfactory manner.

The situation was aggravated by illegal connections to the sewer and by the dumping other sorts of waste. Soon the sewer was completely blocked and was abandoned shortly after Turgot's death in 1751. The land upon which the reservoir for flushing was built was sold in 1779. Prior to 1850, the water management system in Paris was inadequate for its growing population.

Waste water was discharged into the Seine, a primary source of the critically limited supply of drinking water. A cholera epidemic in 1832 carried off more than 18,000 Parisians out of a population of 800,000 and focused the public authorities’ attention on hygiene. At the time, the bacterial cause of the disease was unknown and it was thought to be caused by noxious odors.

Did You Know?

• The first underground sewer in Paris was built in 1370 under Rue Montmartre by provost Hugues Aubriot.
• The Romans built a small number of sewer lines on the Left Bank, including one connecting the Cluny baths to the Seine.