The river Hemavati is a tributary of the river Kaveri. It flows to the north of Kodagu and also marks part of Kodagu's northern border. It is a main water supply for the Harangi reservoir near Hallagunda. A tributary (or affluent or confluent) is a contributory stream, a river that does not reach the sea, but joins another major river (a parent river), to which it contributes its waters, swelling its discharge. ... The Cauvery (sometimes written as Kaveri) is one of the major rivers of southern India. ... Kodagu (also called Coorg, especially in English) is a district of Karnataka state, India. ...