It was the great hydraulic intervention (271 b.Ch.) of the Roman consul Curio Dentato who brought to life the Falls, had not only the merit to receive the Velino waters that became swampy in the Sabina (the Reatina Plain), but also connected the two catchment basins (Nera-Velino) and the two rivers became one with one attributing to the other. If on one hand the so-called “Curiano Channel” made life easy for the Sabina inhabitants, on the other hand it created many inconveniences to the lower Valnerina and for the Interamna Plain ( Terni ) inhabitants. It was, during the overflowing periods of the two rivers that the territory underneath was often subjected to flooding.
For the functioning of the channel, famous is the legal battle (54 b.Ch.) of which we don’t know the final result, between Marco Tullio Cicerone, defender of the Sabina inhabitants (they want the enlargement of the channel) and Aulo Pompeo, defender of the Interamnati (they were against improved interventions). Always to confirm the risks of the flooding, the historian Caius Cornelius Tacitus refers of a great flooding of the Valnerina and of Interamna until Rome, (the Nera is one of the greatest attributes of the Tiber) which happened around the 15 b.Ch., under the Emperor Tiberius.
With the Fall of the Roman Empire, the barbaric invasion and the development of the feudal system the planed territories and the countryside were gradually abandoned. The lack of maintenance of the Curiano channel caused the raising of the base level and as a consequence the re-swamping of the Reatina Plain. We need to wait till beginning of the XV century to re-do a new land reclamation.
In 1418 after some battles with the Ternan people who were against the intervention because they were afraid of further overflowing, Braccio Fortebraccio da Montone, in that time, lord of a large part of the church territories which included Terni and Narni, gave the work to the engineer Aristotile Fioravanti who concluded it.
in 1422 creating a new channel called “Reatino”. The following year (1547) on the commission of Pope Paolo III, a third channel was created by the Florentine Architect Antonio da Sangallo the Younger. The intervention, made 40 years later, wasn’t sufficient and in 1596 the Pope Clemente III decided to commission a group of engineers and plumbers for doing a general recognition of the whole territory.
In 1601 the architect Giovanni Fontana inaugurated the last and definitive “Clementino channel” excavated in accordance to the ancient Curiano channel characterized by a strong inclination in the last 400 metres and from the presence of a regulatory bridge which had to control the Velino waters during the overflow periods.
In 1787 the architect Andrea Vici made a diagonal cut to the second drop, deviating part of the water and creating a lateral cataract in order to increase the surface volume of the water and to diminish the impact at the bottom of the Nera Valley . This is the last adjustment which gave to the Falls the present day aspect, and therefore is considered one of the most beautiful and suggestive sceneries in Italy.