In 1852, Grand Duke Leopold II of Lorraine approved Alessandro Manetti ’s project to drain Lake Bientina, which provided for diverting the Imperial Canal built slight more than a century before on a project by Leonardo Ximenes.
The diverted emissary was to pass under the bed of the River Arno by means of a so-called "barrel", that is to say an underground conduit measuring 255 meters in length.
The first stone of this extraordinary work of hydraulic engineering was laid on September 16, 1854. The Grand Duke was so struck by the impressiveness of the work, which ended in 1859, that he described the various construction phases in his Governo di Famiglia. The daring structure can still be admired today.
Source: Itinerari Scientifici in Toscana
Alessandro Manetti & hydraulic engineering
From 1854 to 1859, Alessandro Manetti perfected the reclamation of Lake Bientina by channelling the waters of the 'Canale Imperiale' into an emissary canal that, with an ingenious underground tunnel system, still undercuts the Arno and flows directly into the sea between Calambrone and Leghorn: the Barrel.
During this period, engineer Manetti lived in Cascina and a plaque can still be seen on the façade of his house, which reads:
“After the Arno in the great floods of February 16th and March 23rd, 1855 - twice broken every restraint near the church of San Cassiano - opened a gap in the plain - prompt and frequent came H.R.H. Leopold Grand Duke. The Grand Duke Leopold II - came to the aid of the afflicted population - and together with his august son, the great hereditary prince - with his presence and with his own advice hastened so much the work of rebuilding - that it was completed in a short time - the nearby countryside was rescued from the fury of the waters - and the interrupted communications were re-established - in memory of the disaster and of the beneficial providences - this marble - on the front of the house inhabited by the engineers of the works - for the draining of the lake of Bientina - where the pitiful sovereign had shelter - Alessandro Manetti director placed“.
- Built in: 1854-1989