681 mw power to be generated from Humla Karnali Cascade Hydropower Project

By Rajan Rawat, Humla, June 15: Electricity will be generated at two different locations under the Humla Karnali Cascade Hydropower Project. During a public hearing held in the presence of local stakeholders on the Environmental Impact Assessment (EIA) report of the project on Saturday, officials said that 681.2 megawatts of electricity would be produced from two sites.

According to Jayaram Mishra, a forest and environmental expert from Desired Engineering Consultancy, electricity will be generated at Yalbang of Namkha Rural Municipality, Dharapori of Simkot Rural Municipality-7 and Chipra of Kharpunath Rural Municipality-4 in Humla district.

He said that, at the first site, a dam measuring 92 metres in length and 46.5 metres in width will be constructed on the Karnali River at Yalbang (Namkha-4). The dam will allow water to be stored for six hours, creating a reservoir of 3.4 kilometres in length.

From the dam, water will be channeled through three intake structures measuring 7 metres high and 6.5 metres wide, with a designed flow of 100 cubic meters per second. The water will then pass through a 13.543-kilometre-long tunnel to a surge tank.

From there, it will flow through a 2,849-metre-long penstock pipe with a diameter of 4.7 metres to the proposed surface powerhouse at Kholaasi village in Simkot Rural Municipality-8, generating 252.4 megawatts of electricity.

Similarly, for the second site, the outflow will pass through a 100-metre-long tailrace canal into a 120-metre-long, 20-meter-wide and 12-meter-deep pond. From there, water will flow through a headrace canal measuring 625 metres in length, 6 metres in width, and 6 metres in height, and then through a 15.97-kilometre-long tunnel with a diameter of 7.4 metres to an underground circular surge tank (20 metres in diameter and 70 metres in height).

Finally, the water will pass through a 425-metre-long penstock pipe with a diameter of 5.2 metres into an underground powerhouse located at Lalichaur in Kharpunath-4, generating 228.8 megawat ts of electricity.

The water will then be returned to the Humla Karnali River via a 425-metre-long tailrace tunnel. The pre-feasibility study for the project was conducted by the consultancy with investment from the Department of Electricity Development under the Ministry of Energy, Water Resources and Irrigation, Government of Nepal. The total estimated cost for both projects is USD 131.762 million dollars.