The Nyang has a length of 307.5 km and originates at 5,000 meters above the sea level from the Cuomuliangla in the Goikarla Rigyu, west of the Mila Mountain. The river joins the Yarlung Tsangpo in Cemeng, Nyingchi, 2,580 meters below its source. With an average flow of 538 cubic meters per second, it has an aquatic power potential of 2.08 million kilowatts. Its largest tributary is the Ba River. It flows past the town of Bayi where it is crossed by the Bayi Zanchen bridge.