The Package-2, encompasses the execution of critical civil and hydro-mechanical works integral to the Lower Arun Hydro-Electric Project. This includes the construction of Adit-5 and Adit-6 leading to the Head Race Tunnel, as well as the Part Head Race Tunnel itself, measuring 10.5 meters in diameter and extending 5.41 kilometers. The scope further covers the Surge Shaft and its gates, the Pressure Shaft along with the Butterfly Valve Chamber and Access Adit, and the Power House, Switchyard, Surface Pothead Yard, and Tail Race Channel. Additionally, the package involves installation of steel liners for the Pressure Shafts, Draft Tube Gates and hoists, and the completion of associated road works and supporting infrastructure. Together, these components form the backbone of the project, ensuring efficient water conveyance, energy generation, and long-term operational reliability.

The project is scheduled to be completed within 54 months and the site is strategically located near Tumlingtar in Sankhuwasabha District of Nepal, approximately 264 km from Siliguri, India.