Q. which of these 9 lakes are not man made during the last century?
They are the first two, named Lake Viverone and Lake Sirio, lakes of the morenic glacial area, that was once the main gold open sky mine of the Romans. (see the Bessa near Mongrando). The Romans deviated the river Elvo in order to have the water to wash the morenic sands, a nearby village called Camburzano, has the roman tent in the coat of arm, curious the trivial dispute about the name origine Camp of Burzio or maybe Camp of good health.
All other lake have been built during about half century. The Lake Trebecco was commissioned during Mussolini pre war era. The last lake to be built and completed is the Lake Bilancino near Florence.
The alignment follows the geographical direction of the Appenines Range. Points from Geneve to Monte Sant'Angelo Apulia in the Gargano Peninsula.
Odds?