Yamzhach (Russian: Ямжач) is a river in Perm Krai, Russia, a left tributary of the Kolva, which in turn is a tributary of the Vishera. The river is 34 kilometres (21 mi) long.[1] It flows into the Kolva 380 kilometres (240 mi) from the Kolva's mouth. The main tributaries are the Passavozh (left) and Zapadnaya (left) rivers.