Answer: Gandak
Notes: Triveni canal is built on Gandak river. Under this project, a 740 m long barrage has been built on Gandak river near Triveni Ghat. It covers the regions of Nepal, Bihar and Uttar Pradesh. In Bihar, It covers districts like Champaran, Saran, Chhapra, Muzaffarpur, Darbhanga, Siwan and Vaishali.
