How Does the Sewage System in Venice Work?

Venice is the capital of northern Italy’s Veneto region. It is built on more than 100 small islands in a lagoon in the Adriatic Sea. It has no roads, just canals. This is the reason why Venice is also known as “La Dominante”, “La Serenissima”, “Queen of the Adriatic”, “City of Water”, “City of Bridges”, “City of Canals”, and “The Floating City”. The lagoon and a part of the city are even listed as a World Heritage Site by UNESCO.

This is one of the main reasons why so many tourists are attracted to this city every year. And during Acqua Alta (A phenomenon during which water from Venice’s canals is spilled onto the streets because of high tides.), many tourists are seen putting on their bathing suits and jumping in the water for a nice swim. But is it safe to swim out there? You must have also heard people complain that ‘it stinks in Venice’. What could be the reason behind this? Does it have something to do with the city’s sewage disposal?

Sewage disposal is the process in which sewage is transported through cities and inhabited areas to sewage treatment, where it is then treated to remove contaminants and to produce environmentally safe waste. Proper disposal of sewage waste is necessary for protecting public health and prevent diseases as well as water pollution produced from sewage contaminants. Today, many modern cities are equipped with a sewage disposal system, and advancing technology has helped a lot in finding more environment-friendly and healthy solutions for disposing and treating sewage.

But it is quite interesting to think about how does the sewage system work in a city that is built on water? Let us find out.

Venice’s Old Sewage System

You would probably be surprised to know that historically, Venice had been one of the cleanest cities in Europe.

In the 15th century, people living in Venice dealt with their waste just like other medieval people did, by throwing it out into the streets. What was different however that Venice’s streets were made of water and the tides conveniently swept the waste out of the city twice a day. This is the reason that the city of Venice was cleaner as compared with other cities. Venice knew how to remove waste using water even before the concept of sewage disposal systems came into existence. As a result, Venice developed one of the first sewer disposal systems to be implemented in the world. This sewage system was a unique, gravity-driven system of underground channels and wastewater drainage. It was called a fognatura.

Then, in the 16th century, a network of tunnels was put in place in the walls and under the pavement of walkways in the city of Venice to collect wastewater and rainwater. These tunnels were called “gatoli” and they collected and channeled the city’s wastewater, which would then flow out into the waters of the lagoon. These tunnels are still present in Venice today and a significant part of Venice still relies on this old, historic sewage system.

This is how the old sewage system exactly works:

Venice Pressure Cleaner

First, the wastewater from houses, buildings and other infrastructures travel down through pipes. (Some of these networks of pipes even date back to 70s and 80s)

This waste then reaches and gets collected in the sewer system built underground.

All this collected waste is then released into the masonry tunnels.

The sewage collects in these tunnels and eventually flows into the Venice’s canals.

All this waste is washed out into the ocean twice a day because of the tides and the old water is replaced by new freshwater.

If this information startled you, you are not alone. The use of canals as a sewage system has come as an unpleasant surprise to the visitors and the tourists of Venice for hundreds of years. The presence of sewage in the canals contributes to the unpleasant smell that tourists often complain of, while the local Venetians ignore the stench of the canals as they are simply used to it.

If this grossed you out a little and you are about to cancel that trip to Venice, wait! There is still some good news.

Venice’s Modern Sewage System

The good thing is that the city is trying to improve its wastewater treatment recently.  Venice already has more than 6,000 septic tanks that can process and treat the wastewater before releasing it into the city’s canals.


The government is also doing its part well. It had recently placed around 140 small biological wastewater treatment plants in the city. Nowadays, the government has also forbidden by law to start a hotel or restaurant without a proper wastewater treatment system. This implies that the government is working hard to solve the problem caused by the older version of the sewage system.

But due to the problematic systems built beneath the city, it is quite difficult to resolve all the sewage system problems. As mentioned earlier, many of the networks and systems are outdated and historic which are causing so many problems for the town and pose a health risk for the millions of tourists visiting Venice.

More About Venice Sewers

If you need more detailed information about the sewage disposal system in Venice, you can check out the documentary called Venice Backstage

Efforts have been made to get the information as accurate and updated as possible. If you found any incorrect information with credible source, please send it via the contact us form
Sky Hoon
Italy Lover. He travel to Europe a few times and loved Italy for its unique language and culture. He loved the idea of Italian food focusing on original taste of the ingredient.
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