The 307.5 km long Niyang River, the largest one of Yaluzhangbu among its five tributes, originates from the Cuomuliangla, west of the Mila Mountain. Its origin, 5,000 meters above the sea level, took its form by the function of the ancient glaciers. The river flows eastwards and joins Yaluzhangbu in Cemeng, Nyingchi. With a drop height of 2,273 meters, an average flow of 538 cubic meters per minute and a yearly flux of 22 billion cubic meters the river boasts an aquatic power of 2.08 million kilowatts.

The river is the sad tear of the holy mountain as the legend says. Viewed as the mother river of the people in Gongbu, its water is crystal clean owing to the well-preserved vegetation in the river reaches.