The English version has been carried out by the English department of liceo classico scientifico Francesco Sbordone
Naples and its waters: a 2700 year long history
Neapolis and the Bolla aqueduct:
The springs and the Royal Formale
Through some historical and speleological evidence found in the area of the so-called "Vicaria" of Castelcapuano and in an underground cavity in the ancient center of Naples, the hypothesis of a Hellenistic-Roman dating of the ancient underground aqueduct known as the "Bolla" is gaining more and more credibility. The water of the "Bolla," spring in nature but rather hard and not sufficiently fresh, originated in the so-called "Valle del Sebeto," at the foothills of Mount Somma in the current territory of Pomigliano d'Arco.
It reached the city of Naples after a journey of about 8 km.
The ancient Bolla aqueduct originated in the locality of Salice in the structure known as the “Casa dell'Acqua” (Water House), already mentioned in some 16th century documents.
The Casa is widely mentioned especially after the damage caused by the earthquake of 1581, during the major consolidation works.
Also referred to as Casa la Bolla or La Volla, it was the endpoint and collection point for the waters that, coming from the springs and wells located in the Benincasa, Tamburiello, and Masseria Preziosa areas, arrived there after an underground journey.
This first branch, called "Benincasa," was still in operation in the 18th century and split into two further branches: one channeled into a canal, the Volla, powered the mill machines; the other, the Formale, flowed in an underground conduit and supplied the city, giving life to the Bolla aqueduct.
The "Formale Reale" was plastered and, after numerous extramural derivations, entered the city of Naples at an altitude of 13 meters above sea level through a channel partly dug into the tuff and covered with a masonry vault.
Near Poggioreale, the channel of the Bolla aqueduct encountered a kind of meter called the "stadera" (balance), inside which the amount of water entering the city of Naples daily was measured (Melisurgo, 1889).
Today, there is still a memory of this meter in the toponym of the street called Via Stadera in Poggioreale.
The average flow of the Bolla aqueduct in 1883 was about 14,000 cubic meters per day, to which the additional volume present in the cisterns, the contribution of the underground aqueduct of "Carmignano," and some springs located between the lower part of the ancient center of Naples and along the Posillipo hill were added.