A name given to a part of the river that flows from the east of Anotatta, before it ultimately divides into the five great rivers, Gaṅgā, Yamunā, etc.

The Ummagga-Gaṅgā is the continuation of the Bahala-Gaṅgā and flows for sixty leagues under the earth, until it reaches the rock named Vijjha. SnA.ii.439; AA.ii.760; UdA.302.