Budhi Gandaki

The Budhi Gandaki — the 'old' or 'wise' Gandaki — drains the Manaslu massif and the western Ganesh Himal along the Tibet border in northern Gorkha. From the high valleys of Nubri and Tsum it cuts a deep, narrow gorge south between the Gorkha and Dhading hills, joining the Trishuli at Benighat on the Prithvi Highway, roughly 80 km west of Kathmandu by road.

Its catchment of around 5,000 km² collects heavy monsoon rain on the south side of the range and snow- and glacier-melt from Manaslu, giving the river a strong, sustained flow squeezed through a valley that is rarely more than a gorge — geometry that dam engineers prize.

That geometry made it the chosen site for the Budhi Gandaki Storage Hydroelectric Project: a 1,200 MW scheme identified in the Gandaki basin studies of the late 1970s, with a dam around 263 m tall planned near Benighat between Ghyalchok (Gorkha) and Salang (Dhading). Its reservoir would stretch some 45 km up the valley, covering about 50 km² and holding roughly 3.3 km³ of water — seasonal storage that would firm up Nepal's dry-season power supply, which run-of-river plants cannot do. Compensation and resettlement for the thousands of families in the reservoir area have been under way for years while financing is settled.

Until the dam comes, the valley remains one of Nepal's quieter corners: the restricted-area trek around Manaslu follows the Budhi Gandaki's gorge almost from the Trishuli confluence to its glacial headwaters.