It is the only natural river in Bologna. It originates in the hills and empties into canale Navile. Torrente Aposa is 7500 meters long.
Originally open, it has been covered during the centuries but it maintains its old shape.
From 1997 to 2000, it has been used as a trunk for drain water. Access from P.zza Minghetti and P.zza S.Martino were then opened. Under Via Rizzoli there is a splendid ruin of Roman bridge (not accessible at the moment) that once made the passage of the "decumanum maximum" (Via Emilia) possible.
Many small rivers originating from canale Savena flow into Torrente d’Aposa.