Gandak, a river of northern India. It rises in the Nepal-Himalayas, flows south-west until it reaches British territory, where it forms the boundary between the United Provinces and Bengal for a considerable portion of its course, and falls into the Ganges opposite Patna. It is a snow-fed stream, and the surrounding country in the plains, lying at a lower level than its banks, is endangered by its floods. The river is accordingly enclosed by protective embankments.
The Little Gandak rises in the Nepal hills, enters Gorakhpur district about 8 m. west of the Gandak, and joins the Gogra just within the Saran district of Bengal.
The Burhi (or old) Gandak also rises in the Nepal hills, and follows a course roughly parallel to and east of that of the Gandak, of which it represents an old channel, passing Muzaffarpur, and joining the Ganges nearly opposite to Moughjr. Its principal tributary is the Baghmati, which rises in the hills N. of Kathmandu, flows in a southerly direction through Tirhut, and joins the Burhi Gandak close to Rusera.
