For example one of its tributaries, the Aniene was navigable in ancient times and played an important role in terms of quarying.
The Tiber river’s major tributaries are:
Chiascio (near the city of Perugia)
Paglia (near the city of Orvieto)
Nera (near the city of Orte)
Farfa (near Rome)
Aniene (north side of Rome)
The river is essentially a stream or torrent until it reaches the Nera near Orte.
It is important to note that the 5 tributaries mentioned above are only the major ones. The geography of Rome and the geological structure of Rome is such that once the river reaches the alluvial plane to the north of the city and the hilly region on which the city was built it is relatively close to sea level and hence involves a more complex region of small water courses. In the earliest period of the city’s development the water around the hills of Rome was collected into drainage systems which were gradually covered into underground streams doubling up as the city’s sewage system, the major of these was the “Cloaca Maxima”.
Principal tributaries into the river tiber around Rome include:
Aniene river: latin name “Anio”, source is on the border between Latium and Abruzzo. It is 99km long)
Almone river: comes from the Alban hills and Alban lake)
Monte Antenne: A 67m high hill to the north of the city. Used to have a settlement on top.
Tor di Quinto: An area on the north side of ancient Rome, built up since the 19th century.
Prati: Like Tor di Quinto it is an area on the north side of Rome, built up during the 19th/20th century.
Vatican hill: the Vatican city is actually situated on what was a hill on the right bank of the Tiber.
Trastevere: area on the right bank of the river, towards the south side of the old city.
Gianniculum: a hill, south side of the Vatican hill.