Natural area, Casalecchio di Reno
The Sluice of Casalecchio is the oldest functioning hydraulic structure in Europe.
It was built in 1300 to regulate and orientate the waters of the river Reno into the heart of Bologna, where water was necessary for both defensive and commercial reasons, as the engine for the water mills.
The importance of the mills is reflected in the names of some streets in Bologna, like via Delle Moline. The huge industrial machines were used for grinding cereal but also for the production of the silk that rendered Bologna famous and flourishing.
Today, the remains of the mills are not visible anymore throughout the water canals but are kept in the Industrial Museum.
The relationship between Bologna and water was complicated: the city had no main river crossing its lands. The construction of the sluice and the net of water canals was a need shared by all Bolognese people, who worked to bring the project to life.
This net underwent constant developments through the years, until the whole city of Bologna was crossed by an amazing network of water canals, all managed from an important naval port.
The water that currently flows inside the city comes, for the most part, from the river Reno, deviated in Casalecchio by the sluice itself.
The water canal starting at the sluice enters Bologna through Via della Grada. The street takes its name from the big gate (grata) that controlled the hydric flux and the passing of commercial vessels. Controlling who used the canals to get inside and out of the city was of an extreme importance in order to avoid the entrance of no-tax products inside the city’s market, which would have been disloyal competition.
In the surroundings of the sluice of Casalecchio we find a highly populated area, near the so-called Lido di Casalecchio. The lido was the place where the Bolognese went to get fresh air and relax during the hot summer days of the sixties, and it was full of dancing floors, hotels and restaurants.
Because of its age and amazing work of engineering, the Unesco has recognized the importance of the sluice of Casalecchio, awarding it as a symbol of "a culture of peace in favour of young people”. The commemorative plaque placed on the sluice on March 26th, 2011 explains that “water is a life source, its conservation and sharing are a source of peace”.