Sewers have existed since the middle ages

This is where ends, among other things, the vortex of the tap, the foaming water of the washing machine or rainwater runoff. It was here, in this gigantic network of 2,400 km, that are thrust all waters used every day by the Parisians. Either all the same distance Paris-Istanbul...

Sewers have existed since the middle ages. But the capital has witnessed many developments in its wastewater treatment system, the period of the ditches pit where Parisians were discharging their waste-water in the streets - spreading pestilential odours and disease - and the time of the underground that we know today.

A network worthy of a metropolis

It is the 19th century that the sewers take their contemporary form. Napoleon III loads the baron Haussmann, prefect of the Seine, to equip Paris of a network of a form worthy of a great metropolis, already populated at the time by 2 million people. Its implementation will be entrusted to Eugène Belgrand, a triple duty: develop a unitary system (wastewater and storm water flow into the same sewer), gravity (flow occurs to the North through the natural slope of the city) and visited. This engineer is also developing some techniques of flushing to hunt deposits agglomerated in the wastewater by single hydraulic force. Because, for security reasons, the sewer cannot use electricity.

Today, all the Parisian streets are connected to the sewer system. "It is a true underground reflection of the city." "Every street is a gallery identified by a plate for the track surface", explains Dominique Lesbros in his book "The scenes of Paris". The quantities of water in transit are phenomenal. "Dry weather, this are over 600,000 m3 of water waste that must be evacuated on a daily basis," he added.

Since the 19th century, this great network has never ceased to be visited. Every year, 100,000 visitors to urge at the entrance of the Museum of the sewers, pont de L'alma. That which is evil filthy image often contiguous to the world of the sewers. Those capital prominently elsewhere in tourist brochures from the city of Paris. His Museum to get an idea of the architecture of this gigantic network and the daily work of its 275 amongst. Some tasks have changed little. The techniques of dredging to remove each year some 10,000 m3 residues - "the bastard", as it is affectionately known amongst - are the same as those being developed in the 19th century. Here, efficient command and new processes are required to be be implemented. Another "tradition": the égoutier trade, which is only six hours a day to avoid infections, is very often transmitted from father to son.

Step of odours

Since 2008, we know a strong acceleration in the number of visitors." "There is a real fantasy on sewer," noted Marie-Christine Amable, Director communication and specialist in the history of the site. "Especially when the Parisian network is one of the only ones in the world to be open to the public." People imagine crazy things about its operation!

The Interior, step of foul-smelling fumes, as you might imagine. The dirty water carried in sewage rejects just smell unpleasant. But this is not the case everywhere. Certain areas are deemed be less fréquentables than others. This is the case of the sewers of prison health, in the South of Paris, whose basements are populated of cockroaches. Those very imposing hammam of the great mosque of Paris, heat and humidity of the sites require, are also very popular by insects.

By security, all of the network is not fully accessible to the public. Hydrogen sulphide exhaust, a highly toxic gas, and polluted water are vectors of risk of serious infections. Logical consequence, in contrast to "cataphiles", visitors who enter illegally within the catacombs and sometimes settled weeks, the "égouphiles", have not yet emerged.