The so called foreign entrance, leads to the backbone sewer of the sewer system, which was built between the years 1895 and 1906. The sewer runs from the Old Town Hall to the Vltava and then to Bubeneč and Císařský Island, the location of the Central Sewage Treatment Plant, Prague. A small part of the conduit is accessible to the public thanks to tours organized by the Prague Information Service.

Still part of Prague sewage system

While the old sewage treatment plant built in the same style, i.e. out of high quality bricks, does not serve the city anymore, the backbone sewage conduit is still a significant part of Prague sewage system. It runs under Pařížská Street and Praguers do not have the opportunity to see it. Three years ago, journalists got the unique chance to see the sewage, when it was under reconstruction. Although it was drained and scoured, it still did not smell very nice.

Breath in before you enter

We were advised to breath in when climbing down the sewer. When we asked why, we were told that ten years ago, one of the employees of the Prague Water Service fell in. Luckily he breathed in just before the fall and was found alive in the sewage treatment plant in Bubeneč.

Why was the sewage under reconstruction?

The sewage system under the city was built at the end of the 19th century by William Heerlein Lindley. The construction operated for one hundred years and is, in many cases, in a better state than some conduits built decades later. The sewage, which gathers water from as far as Vinohrady and the New and Old Town, was reconstructed not so much because it would serve out but because the soil around it was no longer compact, mainly as a result of the flood in 2002. The reconstruction made sure the room between the walls and the soil was filled. The special material used to fill the gaps gave the sewage its original solidity.

The only intervention

The only intervention in the original Lindley work is that of the ceramic drain in the bottom part of the sewage this was replaced with basalt, which is maximally resistant to aggressive water and durability. The renovation was possible thanks to Lindley’s great idea to make a network of canals in such a way that it is possible to block a certain branch and lead the sewage through a different one. Prague has some five hundred kilometres of sewage conduits aged over 80 years, out of the total number of three and a half thousand conduits, so there is always enough repair work to be done. An interesting thing is that it is not always the oldest parts that need reparation.