Riss

Riss

Country	Germany
Basin features
Main source	Upper Swabia 47°57′32″N 9°43′44″E / 47.95889°N 9.72889°E / 47.95889; 9.72889
River mouth	Danube 48°17′8″N 9°49′6″E / 48.28556°N 9.81833°E / 48.28556; 9.81833Coordinates: 48°17′8″N 9°49′6″E / 48.28556°N 9.81833°E / 48.28556; 9.81833
Progression	Danube→ Black Sea
Physical characteristics
Length	50 kilometres (31 mi)

The Riss (Ger: Riß) is a small river in Baden-Württemberg, south-western Germany, right tributary of the Danube. Its source is in Upper Swabia, between Bad Waldsee and Bad Schussenried. It flows north, through the town of Biberach an der Riss. It then flows into the Danube one mile north of Risstissen between Ehingen and Erbach, approximately 20 km upstream from Ulm. Its total length is approximately 50 km.

The Riss gave its name to the Riss glaciation, an ice age.