The project site starts from confluence of the Songad river on the Bhagirathi River in the Garhwal Himalaya to down stream at Thirang gad confluence with Bhagirathi river. The barrage site is next to NH 108 at Loharinag Temple. The Project has a mountainous catchment area of , of which (56%) is covered in snow or glacier. The source of the Bhagirathi is about above the barrage.