The headwaters of Poiqu and Bhote-Sun Koshi River are arranged at the Zhangzangbo Glacier in Tibet. The conduit streams out of the Lumi Chimi lake. Exactly when entering Nepal, it is called Bhote Koshi. Progress downstream, from the town of Bahrabise onwards, it is called Sun Koshi.
In July 1981, a sudden ice exuberant slide realized a Glacial Lake Outburst Flood in the moraine-dammed . The accompanying refuse stream pounded frameworks, and sections of both the Arniko and the Nepal–China turnpikes