History of Koshi River
The Kosi River, called Koshi in Nepal (कोशी नदी), is a transboundary river between Nepal and India, and is one of the largest tributaries of the Ganges. The river, along with its tributaries, drains a total area of 69,300 km2 (26,800 sq mi) up to its confluence with the Ganges in India (29,400 km2/11,400 sq mi in China, 30,700 km2/11,900 sq mi in Nepal and 9,200 km2/3,600 sq mi in India). The watershed also includes part of Tibet, such as the Mount Everest region, and the eastern third of Nepal. The river basin is surrounded by the ridges separating it from the Brahmaputra in the north, the Gandaki in the west, the Mahananda in the east, and by the Ganges in the south. The river is joined by major tributaries, approximately 48 km (30 mi) north of the Indo-Nepal border, breaking into more than twelve distinct channels with shifting courses due to flooding. Kamlā, Bāghmati (Kareh) and Budhi Gandak are major tributaries of Koshi in India, besides minor tributaries like Bhutahi Balān. Over