The Rienz (German pronunciation:; Italian: Rienza) is a river in South Tyrol, Italy. Its source is located at 2,180 m of altitude, in the Dolomites mountains, south of Toblach: near Toblach it enters the Puster Valley, and, after 90 km (56 mi), it meets the Eisack river in the city of Brixen, at 550 m of altitude.
The Rienz flows through the following municipalities (source to mouth): Toblach, Niederdorf, Welsberg-Taisten, Olang, Rasen-Antholz, Bruneck, St. Lorenzen, Kiens, Vintl, Mühlbach, Rodeneck and Brixen.
The most significant affluents are:
- Ahr, forming the Ahrntal and responsible of 1/3 of the total discharge.
- Antholzer Bach.
- Gran Ega (Val Badia).
- Gsieser Bach.
- Pragser Bach.
- Pfunderer Bach.
- Wielenbach.
The maximum discharge of the Rienz is around 60 m3/s.
