Canal cleaning in Venice. Sewerage in Venice. The tides are like cleansing

In 1966, there was a flood in Venice. The water rose almost two meters higher than usual and stayed for almost a day. The cause of the incident is an unusually high tide. After such a terrible acqua alta (as the tides are called in Italy), the world community begins to propose projects to “save Venice”, and the Italian authorities in 1973 issue a law recognizing the problem of Venice as a common problem for the whole country.

In particular, environmental measures were taken. In 1975, the modernization of the city's water supply system began. Stop at the first stage. Artesian wells were recognized as the culprits of soil subsidence. In fact, the organization of the city's water supply system in the lagoon has always been a problem.

Currently, the water conduit to the city is laid from the town of Skorce. Local wells are sources of San Benedetto mineral water. And once the townspeople collected rainwater. Elements of the old city water supply have been preserved to this day: guests of Venice often ask guides what kind of unusual architectural structures in the form of stone pedestals stand in the squares? And these are artesian wells that were used to collect rainwater. In the pavements today you can find special holes organized for the flow of water - pilelle.

It was not easy to build an artesian well. First of all, it was necessary to allocate a large area in order to ensure the collection of water. This explains why all the wells are in the squares. Then a pit had to be dug at least 20 feet deep. If it was not possible to dig a hole of sufficient depth, the territory surrounding the well was raised higher.

The walls of the pit were covered with waterproof clay and carefully isolated from the penetration of salt water. This was required by the hydrogeological characteristics of the soils of the lagoon. The pit was covered with river sand, alternating layers of fine and coarse sand and creating a natural filter. A well was built in the center, and two or four pilelles - water intake hatches - were symmetrically located around. Through the pilelle, rainwater passed into the pit, filtered through the sand and penetrated into the central well, from where the townspeople took water for their needs.

The cost of building an artesian well was very high. The authorities could not provide all the townspeople with water due to lack of funds in the treasury, but some wealthy families built water collection facilities at their own expense. On such wells, inscriptions and bas-reliefs are still preserved, by which the townspeople learned to whom they owe unhindered access to fresh water.

Do you know?..

Venetian artesian wells had fundamental differences from artesian wells, although they were sometimes called wells. The water in the wells did not come from underground aquifers. The wells were fed solely by collecting rainwater filtered through the sand.

"History of the Venetian plumbing", BC "POISK", tell friends: May 20th, 2017

Venice. Look into the well and don't die. December 9th, 2015

It is impossible not to notice that wells in Venice are everywhere. Despite the fact that now water has been brought to the city, no one is going to destroy the wells, of which there are over 2,000, and moreover, they are still an urgent need. Although now all of them are sealed just in case for sanitary reasons, the liquid in them is too manure with microorganisms that are harmful to health. But there is no doubt that in case of urgent need, the wells will be opened and water will flow from them again.



By the way, they were sealed quite recently, 50 years ago. Although water was brought to the city much earlier, wells were still the most necessary of all the structures that were once erected in Venice. Moreover, the builders were pursued by two dangers: how to find fresh water in the middle of the salty sea, and how to protect wells with drinking water from flooding during floods. The ancient architects brilliantly coped with the first task.


The wells are not as deep as they seem. It was difficult to break through to the aquifers beyond the silt and scree rocks on the islands, and most of the wells are ancient cisterns, still known from Roman times, where rainwater was drained through pipes, filtered and exited into the main part of the tank.


Most of the wells in Venice are public, located in the squares - campos - or streets, the smaller ones are private, in courtyards, patios or basements of houses. But there were also deeper wells that passed through sedimentary rocks into aquifers and selected drinking water.

Even in the courtyard of Palazzo Ducale, the Doge's Palace, there are huge marble-bronze wells. Of course, they were sealed long ago, and no one knows the state of the water in them today, but you can be sure that in case of urgent need they can be easily cleaned and put to work.


Another interesting observation: the beautiful bases and rings of wells are nothing more than worn-out bases and capitals of columns of various buildings. sometimes Roman, which, for their power and beauty, it was decided to preserve. Practically, looking at the wells, you see the history of ancient Venice, and even the whole of Rome.


Floods were a real disaster for wells. If everything was in order with them on the high islands, then in the low-lying part, just in the area of ​​​​the often flooded Piazza San Marco, the water could overflow over the edge and then trouble would come. It was very difficult to clean the cisterns and wells from sea water.


Another thing that dictated the careful separation of drinking water from sea water was the TOTAL lack of sewerage in Venice. Moreover, as such, there is no sewage system in Venice to this day.


Yes, yes, you understood everything correctly, even today the sewerage from the houses of Venice merges directly into the canals and into the lagoon. It seems incredible, but it's true! This is dictated by two considerations: firstly, in Venice there are no harmful industries to poison the waters of the bay, and the only large plant - an oil refinery - is located on the mainland dadeco. In addition, it makes no sense even today to pull sewage pipes into the city, they safely go into the sea and get lost in it without a trace. The city itself was built quite competently from the very beginning, and all its sewage was carried out into the lagoon with constant ebbs and flows, so that the canals always have the purest water. The very mechanism of the currents existing in the city, thanks to properly laid channels, is arranged like gas exchange (oxygen - carbon dioxide) and air ventilation in the lungs of a person. Small sewers carry sewage into the Grand Canal, which, in turn, into the lagoon. The lagoon is separated from the Adriatic Sea by a sandy spit, which has three straits - Chioggia, Lido and Malomokko. The above three straits, thanks to the currents they form, clean all the channels available in the city, thereby allowing the city to successfully do without the usual city sewerage. Therefore, you will never find any poop, no slop and a heavy smell of rot in the waters of Venice. A healthy city is like a living organism - it lives and breathes in full force.

Description of Venice is not easy to do. It's not just beautiful views. It is also a city where people live, where there is production, transport and services. But how does the “Venice system” work? How does the tide flow in the lagoon? How were channels and banks created? What are the palaces on? Where are the gas pipes and electricity going? What problems does such high humidity cause in the city?

Let's watch this video in Italian, which will answer all our questions. By the way, everyone who learns Italian will benefit twice:

1. Practice speaking Italian
2. They will receive a lot of new and interesting information about Venice, which they are unlikely to have seen or heard somewhere before.

Everyone else (who is not strong in Italian) can read the translation of this video below. But this does not mean that the video is not worth watching! After all, we don’t turn off a song in a foreign language because we don’t understand its words, right? Isn't Italian the music?

Venice is in the middle of the lagoon. Attention: this is not the sea! It is a shallow basin separated from the sea by a narrow strip of land. The lagoon empties and fills with new water 2 times a day through 3 bays. Water comes in and out 60 times a month, 730 times a year.

Venice is an island?

Not certainly in that way. It consists of 124 islands (631 hectares), which have been gradually inhabited since the 7th century after the birth of Christ. Venice was not founded from a center that then expanded. On the contrary, it came from different settlements that united with each other.

Islands of Venice

The main islands on which it is located were practically independent settlements with such characteristic common elements as a church, a field and one or more water wells. Each field, as a rule, was washed by one channel. If the channel is not visible today, it means that it went underground at a later date. Thus, it became an “earthen canal”, i.e. a closed canal, transformed into a pedestrian route.

How the Venetians protect the shores of the city from water

The Venetians always had to reclaim land from the lagoon and protect it from water. The edges of the coasts of the island are protected by brickwork, so that erosion does not drag the land away from the city. Often, in order to have more space, entire sections of the lagoon were filled with buildings, but protecting the islands from water is not so simple. Over the years, brickwork becomes less and less waterproof, so restoration is needed. But how to do that?

How channels are cleaned

The section of the channel is closed and all water is sucked out of it. Thus, sediments accumulated in the canal over the years are removed. In the second half of the 20th century, 20 years without such cleaning was enough to make several city canals impassable for boats.

The stone protection of the shore is constantly exposed to brackish water, which, as a rule, destroys the bricks and the mortar between them. The tides that rise and fall every day, as well as the water eddies caused by the engines, release the bricks from the masonry, which float away. In the most serious cases, all sections of the wall must be rebuilt. It is often also necessary to introduce hydraulic binders inside the masonry to compensate for most of the wall. When the mortar dissolves, something worse happens: the wall is no longer watertight, water seeps in and begins to wash away the earth behind the masonry.

Venice streets

Streets in Venice are called calli, but may have other names: fondamenta (street along the canal), ruga (street surrounded by shops), piscina (swampy land), ramo (side street of the main road, often dead end). Sometimes, due to the fact that there was little space for construction, it was necessary to design paths under buildings or steal a piece of the road without narrowing its width. Some of the roads are called "Salizades" (important path laid down in ancient times).

I offer you another thematic tour through the streets of Venice. Evening Venice is simply unique!

How the roads of Venice are made

In past centuries, there were few paved roads. Since the 17th century, public areas have been paved using trachyte paving stones. Trachite is a compact and durable stone that makes a big difference: it stays tough when worn. Trachitis, however, is not eternal, so it is necessary to restore the pavement from time to time. Replace only hopelessly destroyed areas. In Venice, even the roads have historical significance.

Venice underwater

It is known that one of the problems in the city is "high water". Higher than normal tide is enough to flood entire urban areas. Restoring the pavement increases the height of the pavement in most flooded areas. Just a few inches difference can make the difference between walking around the city or not being able to leave the house.

Venice is an ancient city, but also a modern city, and all modern cities need electricity, water, telephone, gas, and public lighting. But where do all the cables and pipelines of these networks go? It is under our feet, or rather under the paving stones.

When roads are restored, it is possible to restore order among all network channels and replace old and damaged ones. In some cases, residents do not even know exactly what utilities are under their floors.

How do all these pipes go from island to island? They do it like people. They use bridges.

Sewerage in Venice

Venice does not have a modern sewer system. It still largely uses the historic sewerage system, made of masonry tunnels known as "gatoli":

• All water goes into these tunnels and from them to the canals.
• Twice a day, the lagoon is emptied and completely filled with water coming from the sea, clearing the channels.
• Many buildings have septic tanks, i.e. tanks where wastewater is treated so that it can be poured into channels.
• However, the sewer system, consisting of "gatoli" and septic tanks, must be constantly monitored. Sometimes the "gatoli" get clogged, the blocked sewage presses against the masonry and risks destroying entire sections of the pebbly walls.

Bridges of Venice

There are 438 bridges in Venice. They are indispensable for city traffic, because they connect the various islands that make up the city. Until the eighteenth century, there were fewer bridges, and the Venetians traveled mainly in rowboats.

Problems in the construction of bridges

When it was planned to build a bridge, sometimes there was a problem: where to build it. Often the exits of the two channels did not match, so some bridges in Venice are slanted.

In the case when the areas where they planned to install the bridge could not be reduced, they preferred to install a wooden bridge, which is much lighter than a stone one. A simple wooden bridge saves a significant amount of road for pedestrians, although it requires constant maintenance. Stone bridges are also not eternal: fastenings are displaced, cracks form, salty dampness settles on plaster, bricks and cement. Consequences are difficult to measure.

Venetian architecture

Venetian buildings are famous all over the world for their beauty and sophistication. For more than a millennium, the Venetians have codified a series of techniques for their own buildings, and have also succeeded in developing ingenious solutions and adapting them to their environment. The main layout of the building goes back to the fondaco house, i.e. the place of residence of a merchant family. On the ground floor there was a warehouse and a store. On the second was a salon, which was called "portego". It was a representative place. The owners' apartment was on the top floor. The servants' quarters were located in the attic.

Palaces of Venice

The main palaces of Venice retained the same basic structure. Urban and working life here was mainly carried out by boat, so the main facade of the house overlooked the canal, and not the inner streets. In many cases the buildings have more than three floors, but the basic three-sided layout was the same.

The salon, often richly decorated, crossed the entire "noble" floor and had two narrower wings divided into rooms. The floors were interconnected by an ingenious system of intersecting stairs, thus, the servants and owners had two entrances and two independent paths of movement around the house. Some crossing points allowed, if necessary, the transition from one path to another.

Be sure to take a tour of one of the Venetian palaces of Ka "Rezzonico from the Russian guide Christina. Here you will feel for yourself what it is like to be a Venetian patrician in the 18th century.

How houses were built in Venice

But how can such monumental buildings stand on such unstable and swampy soil of the lagoons? In Venice, before houses were built overlooking the canal, wooden posts were driven vertically into the ground to make it more solid. Then, 2 layers of thick boards were laid horizontally, and a layer of stone blocks was laid on top. From here began the foundation of the building. Using a bit of imagination, we can say that Venice is upside down forest.

Features of the architecture of buildings

The building was designed in such a way that it could move, adapting to various shifts in the soft earth. One can imagine a palace as a box in which the walls and bottom are not rigidly built into the perimeter. There are no rigid connections between the masonry, and the walls have such supports to ensure the relative movement of individual parts.

The bearing walls of the building are almost always strictly perpendicular to the channels. Thus, they are the only load-bearing structures that support the weight of all floors. The façade does not function as a supporting wall, so it can be decorated with many windows that allow light to freely enter the building.

Today, when observing some of the buildings, one can notice that the perimeter walls slope slightly inwards. In fact, walls in case of settling, instead of opening outward, tend to rest inward on the roof and floors, thus avoiding instability. The roof structure helps close the "box" of walls and floors.

What are the houses in Venice made of?

The floors and roofs of the houses are made of wood, a light and elastic material that easily resists changes in the geometry of the building without cracking. The floors, during construction or in the following centuries, were attached to the walls with metal rods that resist the collapse of the outside perimeter of the wall. However, over time, the rods can cause damage to the masonry, because the metal rusts and the rust increases in volume, destroying the stone used as the head of the rod.

Humidity and dampness

For all cities, dampness is one of the most serious problems for buildings and structures. For Venice, this problem is much more serious than for anyone else. In fact, salt water vapor destroys any building materials.

The most destructive for brick buildings is rising moisture. A wall is not much different from a sponge and absorbs moisture from the foundation through the thin channels they exchange. Salt makes things even worse. This refers to masonry dissolved in water, which then evaporates. Salt crystallizes and increases in 12-fold volume, destroys the brick.

Floor beams also suffer from moisture, as water promotes the reproduction of fungus and bacteria in the wood. The traditional antidote was to build stone blocks from Istria into the wall. It is a very compact limestone stone that acts as a barrier to rising moisture. Today, however, the water level is higher. It covers the level of the stone, destroys it and increases the problem.

How to get rid of dampness in Venice

Now there are many solutions to this problem, for example, not plastering part of the building, thereby increasing air permeability. Another solution is to so-called "cutting the wall" by inserting a waterproof membrane capable of stopping rising moisture. There is also a chemical option such as injection resins that saturate the pores of the masonry. Thus, they reduce their absorption capacity.

Humidity, erosion and swampy soil are all features of the lagoon that Venetians constantly encounter. To continue to live in such a changing environment, they had to be able to adapt to change and respond quickly to the constant and inevitable degradation of the city. It is necessary to tirelessly carry out maintenance work to keep the city in proper condition.

Conclusion

As you can see, Venice is the result of 1500 years of continuous work and in-depth study of its urban landscape. Only thanks to the tireless care of its inhabitants, it has been preserved over the centuries and will live in the next.

Did you like our description of the city of Venice? If yes, then do not be greedy and share the link with your friends 🙂

In the section on the question How does the sewerage system work in Venice? given by the author Natalia from Tver NF-90 the best answer is There is no sewerage in Venice. Her famous channels perform this function. Small canals carry all the waste to the Grand Canal, and from there to the Adriatic Sea. Venice is so well-built that all sewage and sewer waters with high and low tides (and this happens 2 times a day) are carried out into the lagoon, and there is always clean water in the canals ... The mechanism of washing the channels with ebbs and flows works akin to ventilation in the lungs and gas exchange - carbon dioxide for oxygen. By our time, the Venetian lagoon has finally formed as a vast water area 56.5 km long and 9.6 km wide, separated from the Adriatic Sea by a sandy spit with three straits: Lido, Malamocco and Chioggia. During high tide, sea water enters through them into the lagoon, raising its level, and at low tide again goes into the sea. These daily currents clean the Venetian canals, allowing the city to do without a sewer cleaning system.
Here, of course, not everything is as simple as on the mainland. They say that recently the sewage system was modernized, which the Venetians are terribly proud of, and a tidy sum has been spent on this. Another source notes, however, that there is no possibility of installing a central sewerage system. Everything is complicated there, both with the foundations of houses, and with the bottom topography. But they definitely did something. One of the Russian-speaking "new Venetians" assures that the system works, and all drains are diverted into the lagoon.
But in some houses there is no such sewage system, so a special sewage boat moves around the city, which serves them.
There are also different versions about the "smell" pursuing unaccustomed tourists. Firstly, sea water evaporates great in sunny weather, and especially during low tide, the smell of sea grass, iodine, is strong, to which is mixed the "aroma" of mussels living there, in the canals.
Plus, in the distant lanes you can feel the painfully familiar smell of Moscow and St. Petersburg entrances. What to do, people are the same everywhere, they save on a paid toilet ...
About public toilets. Of course they are, but not many. And prices change depending on the season. During "hot" periods, using a public toilet in Venice will cost 3 euros per day. For those who book this service online, the price is reduced to 2 euros.
Visiting a public toilet during the carnival costs twice as much compared to the usual period, when tourists pay only 1.50 euros. For indigenous people, lower rates are provided: 0.25 cents if they have a "WC card-subscription" l9; costing 3 euros. Those who are over 60 years old enter for free, as they are given a "WC card-subscription".

Perhaps, all over the world, Venice is second only to one city in terms of romance - Paris. Gondoliers, canals instead of streets, fresh sea breeze from the Adriatic - what could be better? But often practical people come up with the question: "How is the sewerage system in Venice?" Add to the confusion and rumors that the city is constantly saturated with the smell of urine and feces. Let's take a look at both questions.

Typical solutions do not fit

Venice is a fairly large city by European standards: more than 260 thousand people. At the same time, only a part lives on the continental part, while the rest live on the islands, which made the city so famous. Of course, the sewerage system in Venice simply cannot be the same as in other cities of the world.

To lay the pipes, thousands of plumber divers would have to work for several years, and even then, if they could find the right heavy equipment to dig the soil at the bottom of deep channels.

It is also impossible to lay pipes at or above water level. In the second case, this would spoil the appearance of the city, which the Venetians are rightly proud of. And in the first one, it would also impede the movement of water transport.

So there is no way to use typical solutions here. Now let's figure out how the sewerage system works in Venice.

The tides are like cleansing

For many centuries, sewerage in this glorious city was simply ... absent. Yes, residents had to pour their waste directly into the canals. Fortunately, nature itself helped them cope with this difficulty. The fact is that four times a day the water level changes here - two high tides and two low tides, like clockwork. Due to this, at low tide, the water, along with all the sewage, went into the open sea, and after a few hours, fresh sea water, without any impurities, came in its place.

All sewage was blown into the Venetian lagoon, which has a very decent size - about 10 kilometers wide and almost 57 kilometers long. Of course, for an area of ​​about 570 square kilometers, several tens of tons of human waste per day do not pose any danger. In addition, many marine inhabitants actively used this - the number of microorganisms for which these wastes are a nutrient medium has increased significantly. As a result, many marine inhabitants settled here, accustomed to eating these microorganisms - from mollusks to small fish, in pursuit of which larger individuals began to swim into the lagoon.

Thus, the Venetians for many centuries killed two birds with one stone - they got rid of sewage, and at the same time they fed fish, which the fishermen actively caught, providing the townspeople with fresh seafood.

System upgrade

Of course, after reading the previous paragraph, many readers will have a question: "How does the sewer in Venice work today?" Do the inhabitants of this beautiful, so romantic city still live the same way as many centuries ago, getting rid of sewage, simply pouring it into open channels?

You can calm down and not worry. Many years have passed since then, much has changed, science and technology have advanced significantly, which allows us to completely solve the problem of removing sewage from the city.

So, how is the sewerage system in Venice today? In fact, it is absent, just like in the years when the city was just being built. The problem was solved in a non-standard way.

A septic tank was installed in each house - about the same as those installed in many private cottages. It separates waste into liquid and solid in the same way, passing the first through filters, and collecting the second in a special container. As a result, a relatively purified liquid is discharged into the channels, as before.

But in order to speed up the removal of sewage, three artificial channels were arranged, providing a much more powerful current throughout the entire area of ​​​​the city. The tides have become even more intense, there is not a single corner in the city that would not be affected by the current. Solid waste accumulates in septic tanks, and specialists are already dealing with them.

Vacuum boats

If we talk about how the sewerage is made in Venice, we can not help but mention the sewers. On land, this work is carried out by specialists with trucks. But in a city where there are almost no roads, but there are enough canals, this responsibility falls entirely on the boats.

Specially designed vessels, equipped with the latest technology, quickly pump out sewage accumulated in septic tanks, and then dispose of them at the appropriate landfills.

Of course, the constant work of specialists in unpleasant conditions, and even those equipped with highly specialized equipment, costs the city budget a lot. But still, it is easier than laying a full-fledged sewer at the bottom of the channels.

The truth about smells

Now that we have figured out what sewerage is in Venice, let's proceed to the next question - is there really a fetid cloud constantly hanging over the city?

Fortunately, no. The romantic city smells only of the salty sea in winter and summer. Rumors about the stench are spread by ill-wishers, and picked up by people who have never been here.

On the one hand, the amount of impurities is too small. Try pouring a tablespoon of urine into a bucket of water - there won't be the slightest smell. And in millions of cubic meters of sea water, liquid waste dissolves just as easily.

In addition, a cool breeze almost constantly blows from the sea, which blows the wind from Venice, bringing freshness and cleanliness to the inhabitants.

So, if you have a trip to this glorious city, you definitely should not worry about an unpleasant smell.

Conclusion

This concludes our article. Now you know how the sewerage works in Venice, and also read something about its history. We hope that the article expanded your horizons and was interesting!