Mahakali river system lies to the westernmost boarder of Nepal. The river has its origin in Api Himal within the Himalayas. The river starts from Milan glacier of India and from the Lipulekh of Nepal and flows southward bordering Nepal and India for most of its length. Mahakali river is named “Sharda” in India. It is a part of Ghagra sub-basin of large Ganga basin. Chamelia and Surnagad river are the main tributaries of Mahakali basin towards Nepal side.
Most of the catchment area(15,260 sq. km) of Mahakali basin lies in India while 35.4 % falls within Nepal. The average discharge of Mahakali river in about 658 m3/s at Sharada Barrage while the flow fluctuates heavily during monsoon and winter season. There are altogether 9 glacial lakes and 164 glaciers within Mahakali river basin in Nepal (CBS 2019). Glacial lake outburst floods (GLOF), flash-flood, landslides and floods are major hazards within the basin. Chamaliya watershed of Mahakali ranks 18th on the overall vulnerability to climate change (Siddiqui et al. 2012).
Mahakali basin supports nearly 18.58 lakhs of population in India and Nepal. The Mahakali River is estimated to yield 2262 MW of hydropower and 14981 GWh of energy annually (Jha 2011).
Dams
Sharda Barrage, for irrigation purpose is installed within Indo-Nepal boarder. Mahakali irrigation project enabled Nepal to use its share from the river. Chameliya hydroelectric project of 30 MW capacity is under construction on Chameliya river, a tributary of Mahakali river. Tanakpur hydroelectric project of 120 MW has been installed in Sharda river at Tanakpur, India. Pancheshwar Dam, a multi-purpose project for irrigation and hydro-electric generation is proposed but final agreement has not been reached between Nepal and India government about the project. Dhauliganga project of 280 MW is also in upper catchment in India.
Biodiversity
In Nepal, Shuklaphanta national park and Api-Nampa conservation area lies within the Mahakali river basin boundary. Dudhwa tiger reserve of India also lies within the basin boundary.
References
Jha, R. (2011). Total run-of-river type hydro-power potential of Nepal. Hydro Nepal: Journal of Water, Energy and Environment, 7, 8-13. https://doi.org/10.3126/hn.v7i0.4226
Siddiqui, S., Bharati, L., Panta, M., Gurung, P., Rakhal, B., & Magarjan, L. D. (2012). Climate change and vulnerability mapping in Watersheds in Middle and High Mountains of Nepal. Department of Soil Conservation and Watershed Management (DSCWM), Government of Nepal.
Environics Trust (2017). State of Mahakali/Sharda catchment of Ganga basin in India and Nepal.
CBS. (2019). Environment statistics of Nepal. National Planning Commission, Government of Nepal