"Lowering the river" is what lies behind the design of most canal locks in the world. I've even seen canals built on viaducts, making the water travel over an obstacle, like railroad tracks or a road. But I've never quite seen the Italian solution to the problem illustrated above. In Manhattan, for example, if a work crew arrived, permits in hand, ready to dig a ditch for a sewer or communication cables, a call to the City's tow trucks solve the problem in no time at all. Tow the car out of the work zone. Done.
Besides, "Why have someone's car towed away and cause someone else problems? It might be my friend's cousin, or my cousin's cousin, or, Dio mio... someone's nonna!"