What is a pozzo or pozzi, you ask? Well, I'll tell you. Read on.
Venice is a city that sits in a saltwater lagoon. It is an island...well, several islands...like about 117 islands. The point is that fresh water is very difficult to find when you are on an island surrounded by saltwater. That's where the marvelous invention of the pozzi come in.
A pozzo is a well, where pozzi is its plural. A typical well is created by digging or drilling down until one finds fresh, potable water. This has been done for centuries. But in Venice, if one digs down to water, it will be that same old saltwater that surrounds and permeates the city of Venice. So, how is a Venetian well different that those of the millennia?
The Venetian engineers who designed and constructed the pozzi knew at what level the lagoon's non-potable water sat under the buildings and open spaces (campi) of Venice. The foundational 'ground' elevation of Venice was created by driving millions and millions of tree trunks into the mud of the lagoon. The church of Santa Maria della Salute that I mentioned a couple of weeks ago had over one-million trees just for its own foundation. These pilings and the soil packed around and on them were used to raise the ground level upon which the city was built to a consistent level.
These engineers knew that they could dig out the area under the campi to a certain level to create huge stone-lined cisterns for storage of rain water. After excavation of a campo, stonework was laid down on the bottom. Stonework was also laid down to form the walls of these large cisterns, as well as a loose stone cylinder which would make up the pit of the well . Then, the stone-lined excavation was filled with sand and covered with loose-fitting paving stones. Finally, a stone well (you know, like a wishing well) was set up in the middle of the campo right above the stone cylinder. Got it? If not, here is a nice cross-sectional drawing of a typical pozzo.
So, all that was needed now was for the rains to fall upon the city of Venice. That rain water seeped through the loose-fitting paving stones of the compo and collected within the sands of the cistern. Viola' -- water for the citizens of Venice.
I hope that you have enjoyed finding out a bit about how the Venetians kept hydrated over the centuries. Today, excellent, fresh water is brought down from the Italian alps, which one can actually see from the campanile of Venice on a clear day.
Each of the photos you see above took a good while for me to get it to the point of being presentable to you. Again, my goal is to give to you an ancient Venice -- a Venice of another time. In next week's article, I'll show you a number of before-and-after transformation which lead to these pozzi images.
Ciao for now,