Gandak Canal is a joint irrigation and power project between India and Nepal on the river Kali Gandaki. Kali Gandaki is one of the major rivers of Nepal and a left bank tributary of the Ganges in India.
Gandak Project at located Valmikinagar (Bhainsaloton), intercepts water of a catchment (37,410 km2 – 90% area is in Nepal) which lies partly in Nepal and partly in India. This project was started in 1959 after joint agreement between nepal and India on 4 December 1959. As a part of bilateral agreement, the Gandak Barrage, a part of Gandak Project, has been built (1968/69.) over the Gandak river for providing irrigation to Nepal, U.P. and Bihar. The irrigation potential of this project is 11,510 km², spread in the district of West Champaran, East Champaran, Muzaffarpur, Samastipur, Saran, Siwan & Gopalganj. The Eastern Gandak Canal Project was taken up in 1960 and Main Canal system was completed in 1975 for flow irrigation in Nepal for the gross commanded area estimated to be 103,500 acres. Hydroelectric potential of the project is minimal i.e. 15 MW (3x5 MW).