Tehri Dam is situated at the confluence of the Bhagirathi and Bhilganga rivers in Garhwal district of Uttarakhand. Tehri Dam is the highest dam in India and the fourth highest dam in the world. This dam has submerged the town of Tehri, which was well known as the seat of Garhwali culture.

River Bhagirathi originates in the Garhwal Himalayas near Gaumukh. It transverses through two districts of Uttarakhand state, viz., Uttarkashi and Tehri, to reach Devprayg, where another head stream, the Alaknanda, joins it to form River Ganga.

Bhilangna River is the major tributary of the Bhagirathi River. Bhilangna rises at the foot of the Khatling Glacier, south of Gaumukh.