Hewa Khola is one of the tributaries of the Tamor River. The intake of the project lies at
approximately 87º49’39” E longitude and 27º 11’ 06” N latitude and at an elevation of 863.5
m amsl (the original river bed level). The powerhouse is located at approximately
87º 47′ 22” E Longitude and 27º 10’ 11” N Latitude and at an elevation of 655 m amsl. The
catchment area of this project is 208 sq. km.
Figure : Project Area (Google Earth)
The area lies in the Lesser Himalaya Zone, immediately south from the boundary with the
Higher Himalaya. The predominant rock types are sandstone, siltstone and mudstone. The
area is mostly covered with forest and cultivated land and tea gardens in the surrounding.
The weathered depth of Siwalik rock provides necessary environment for forest and
The project’s headworks is situated on the Hewa Khola between the border of two Village
Development Committees (VDCs) namely Yangnam and Bharapa of Panchthar District.
Right bank of the diversion dam lies in Bharapa VDC and the left bank in Yangnam VDC.
The powerhouse site is located at Nangin VDC approximately 2.75 km upstream from the
confluence of the Hewa Khola and Pheme Khola in Nangin VDC of Panchthar district. The
intake structures, gravel trap, approach canal, settling basin, headpond are compact and
are located on the left bank of the Hewa Khola. Headrace tunnel, surge shaft area,
penstock and powerhouse also lies at the left bank. The outdoor switchyard is located on
the right bank of Hewa Khola in Nangin VDC. After generating power , the water is
discharged back to the Hewa Khola approximately 40 m downstream of the powerhouse.