The Rienz is a river

River

A river is a natural watercourse, usually freshwater, flowing towards an ocean, a lake, a sea, or another river. In a few cases, a river simply flows into the ground or dries up completely before reaching another body of water. Small rivers may also be called by several other names, including...

 in South Tyrol

South Tyrol

South Tyrol , also known by its Italian name Alto Adige, is an autonomous province in northern Italy. It is one of the two autonomous provinces that make up the autonomous region of Trentino-Alto Adige/Südtirol. The province has an area of and a total population of more than 500,000 inhabitants...

, Italy

Italy

Italy , officially the Italian Republic languages]] under the European Charter for Regional or Minority Languages. In each of these, Italy's official name is as follows:;;;;;;;;), is a unitary parliamentary republic in South-Central Europe. To the north it borders France, Switzerland, Austria and...

. Its source is located at 2,180 m of altitude, in the Dolomites

Dolomites

The Dolomites are a mountain range located in north-eastern Italy. It is a part of Southern Limestone Alps and extends from the River Adige in the west to the Piave Valley in the east. The northern and southern borders are defined by the Puster Valley and the Sugana Valley...

 mountaines, south of Toblach

Toblach

Toblach is a comune/Gemeinde in South Tyrol in the Italian region Trentino-Alto Adige/Südtirol, located in the Puster Valley about 110 km northeast of the city of Trento and about 70 km northeast of the city of Bolzano, on the border with Austria.As of November 30, 2010, it had a...

: near Toblach it enters in the Puster Valley, and, after 90 km (56 mi), it meets the Eisack

Eisack

The Eisack is a river in Northern Italy, the second largest river in South Tyrol. Its source is near the Brenner Pass, at an altitude of about 1990 m above sea level. The river draws water from an area of about 4,200 km². After about 96 km, it joins the Adige river south of Bolzano. At first the...

 river in the city of Brixen

Brixen

Brixen is the name of two cities in the Alps:*Brixen, South Tyrol, Italy*Brixen im Thale, Tyrol, AustriaBrixen may also refer to:*Bishopric of Brixen, the former north-Italian state....

, at 550 m of altitude.

The Rienz flows through the following municipalities (source to mouth): Toblach, Niederdorf, Welsberg-Taisten, Olang

Olang

Olang is a comune in South Tyrol in the Italian region Trentino-Alto Adige/Südtirol, located about 100 km northeast of the city of Trento and about 60 km northeast of the city of Bolzano.-Geography:...

, Rasen-Antholz

Rasen-Antholz

Rasen-Antholz is a municipality in South Tyrol in the Italian region Trentino-Alto Adige/Südtirol, located about 110 km northeast of the city of Trento and about 60 km northeast of the city of Bolzano, on the border with Austria.-Geography:...

, Bruneck

Bruneck

Bruneck is the largest town in the Puster Valley in the Italian province of South Tyrol. Bruneck lies at the confluence of the Ahr with the Rienz Bruneck is the largest town in the Puster Valley in the Italian province of South Tyrol. Bruneck lies at the confluence of the Ahr with the Rienz...

, St. Lorenzen

St. Lorenzen

St. Lorenzen is a comune in South Tyrol in the Italian region Trentino-Alto Adige/Südtirol, located about 100 km northeast of Trento and about 50 km northeast of Bolzano...

, Kiens

Kiens

Kiens is a comune in South Tyrol in the Italian region Trentino-Alto Adige/Südtirol, located about 100 km northeast of Trento and about 50 km northeast of Bolzano.-Geography:...

, Vintl, Mühlbach, Rodeneck

Rodeneck

Rodeneck is a comune in South Tyrol in the Italian region Trentino-Alto Adige/Südtirol.Rodeneck borders the following municipalities: Kiens, Lüsen, Mühlbach, Natz-Schabs, St. Lorenzen and Vintl.-Origin:...

 and Brixen.

The most significant affluents are:

• Ahr
  Ahr (South Tyrol)
  The Ahr is a river in South Tyrol, Italy, which flows through the Tauferer Ahrntal.- References :* Information about the Ahr in and ....
  
  , forming the Ahrntal
  Ahrntal
  Ahrntal is a Gemeinde and valley in South Tyrol in the northern Italian region Trentino-Alto Adige/Südtirol.-Geography:The municipality lies about 120 km northeast of the city of Trento and about 70 km northeast of the city of Bolzano, on the border with Austria...
  
   and responsible of 1/3 of the total discharge
  Discharge (hydrology)
  In hydrology, discharge is the volume rate of water flow, including any suspended solids , dissolved chemical species and/or biologic material , which is transported through a given cross-sectional area...
  
  .
• Antholzerbach
  Antholzerbach
  - References :* Information about the Antholzer Bach in and ....
  
  .
• Gran Ega (Val Badia).
• Gsieser Bach
  Gsieser Bach
  - References :* Information about the Gsieser Bach in and .- External links :...
  
  .
• Pragser Bach
  Pragser Bach
  - References :* Information about the Pragser Bach in and ....
  
  .
• Pfunderer Bach
  Pfunderer Bach
  - References :* Information about the Pfunderer Bach in and .- External links :...
  
  .
• Wielenbach.

The maximum discharge of the Rienz is around 60 m³/s.