Spatial heterogeneity in basin hydrology and hydropower potential: Implications for climate resilience and economic development in Nepal

Abstract

Nepal's vast hydropower potential is central to its long-term economic development; however, it exhibits pronounced spatial heterogeneity and is increasingly vulnerable to climate-induced risks. This study employs an integrated, Basin-scale analytical framework to evaluate the hydrological productivity and economic viability of major river Basins, explicitly linking these indicators to climate resilience. The results reveal a strong spatial concentration of water and energy resources, with the Koshi, Gandaki (Narayani), and Karnali Basins collectively contributing over 68% of the national runoff and accounting for more than 94% of the country's economically feasible hydropower potential. A key finding is the decoupling of Basin size from hydrological efficiency. The Mahakali Basin demonstrates the highest runoff intensity (4.07 million m³/km²/year), whereas the much larger Karnali Basin exhibits the lowest (1.08 million m³/km²/year). While theoretical and economic hydropower potentials are strongly correlated (R² = 0.94), conversion efficiencies vary substantially across Basins due to site-specific topographic, geological, and infrastructural constraints. Climate projections further indicate significant threats to hydropower reliability, including Basin-specific reductions in mean annual flow of up to 48%, accelerated glacier retreat, and increased sediment loads. These risks are particularly acute given Nepal's heavy reliance on run-of-river hydropower projects. The study concludes that realizing hydropower potential in Nepal under a changing climate requires a strategic shift toward climate-adaptive, Basin-specific planning, emphasizing storage-based hydropower, diversification of renewable energy sources, and strengthened transboundary water governance to ensure resilient and sustainable development.

Keywords

climate vulnerability / hydrological productivity / hydropower potential / integrated water resources management / Nepal river basins / run-of-river hydropower / transboundary water governance

References

[1] ADB. (2023). Climate change action plan, 2023–2030. Asian Development Bank. https://www.adb.org/sites/default/files/institutional-document/920956/climate-change-action-plan-2023-2030-boardpaper.pdf

[2] Adhikari, D. (2021). Hydropower development in Nepal. Economic Review, 18(4), 70–94. https://www.nrb.org.np/contents/uploads/2021/09/vol18_art4.pdf

[3] Andermann, C., Bonnet, S., Crave, A., Davy, P., Longuevergne, L., & Gloaguen, R. (2012). Sediment transfer and the hydrological cycle of Himalayan rivers in Nepal. Comptes Rendus. Géoscience, 344(11–12), 627–635. https://doi.org/10.1016/j.crte.2012.10.009

[4] Arriagada, P., Dieppois, B., Sidibe, M., & Link, O. (2019). Impacts of climate change and climate variability on hydropower potential in data-scarce regions subjected to multi-decadal variability. Energies, 12(14), 2747. https://doi.org/10.3390/en12142747

[5] Aryal, S., Ghimire, S., Tiwari, S., Baaniya, Y., & Pandey, V. P. (2024). Evolution and future prospects of hydropower sector in Nepal: A review. Heliyon, 10(10), e31139. https://doi.org/10.1016/j.heliyon.2024.e31139

[6] Aryal, S., & Pokhrel, Y. (2025). Spatio-temporal heterogeneities in hydrologic dynamics across the Asian Water Tower. Journal of Hydrology, 662, 133951. https://doi.org/10.1016/j.jhydrol.2025.133951

[7] Bajracharya, S. R., Pradhananga, S., Shrestha, A. B., & Thapa, R. (2023). Future climate and its potential impact on the spatial and temporal hydrological regime in the Koshi Basin, Nepal. Journal of Hydrology: Regional Studies, 45, 101316. https://doi.org/10.1016/j.ejrh.2023.101316

[8] Baral, S., Nepal, S., Pandey, V. P., Khadka, M., & Gyawali, D. (2023). Position paper on enhancing water security in Nepal. Prepared for the United Nations 2023 Water Conference, March 22–24, 2023, New York.

[9] Basheer, M., Nechifor, V., Calzadilla, A., Ringler, C., Hulme, D., & Harou, J. J. (2022). Balancing national economic policy outcomes for sustainable development. Nature Communications, 13(1), 5041. https://doi.org/10.1038/s41467-022-32415-9

[10] Baurzhan, S., Jenkins, G. P., & Olasehinde-Williams, G. O. (2021). The economic performance of hydropower dams supported by the World Bank Group, 1975–2015. Energies, 14(9), 2673. https://doi.org/10.3390/en14092673

[11] Bhandari, R., Saptalena, L. G., & Kusch, W. (2018). Sustainability assessment of a micro hydropower plant in Nepal. Energy, Sustainability and Society, 8(1), 3. https://doi.org/10.1186/s13705-018-0147-2

[12] Bhattarai, U., Devkota, L. P., Marahatta, S., Shrestha, D., & Maraseni, T. (2022). How will hydro-energy generation of the Nepalese Himalaya vary in the future? A climate change perspective. Environmental Research, 214, 113746. https://doi.org/10.1016/j.envres.2022.113746

[13] Bookhagen, B., & Burbank, D. W. (2010). Toward a complete Himalayan hydrological budget: Spatiotemporal distribution of snowmelt and rainfall and their impact on river discharge. Journal of Geophysical Research: Earth Surface, 115(F3), F03019. https://doi.org/10.1029/2009JF001426

[14] Dahri, Z. H., Ludwig, F., Moors, E., Ahmad, S., Ahmad, B., Ahmad, S., Riaz, M., & Kabat, P. (2021). Climate change and hydrological regime of the high-altitude Indus basin under extreme climate scenarios. Science of the Total Environment, 768, 144467. https://doi.org/10.1016/j.scitotenv.2020.144467

[15] Development Asia, (2025). Enhancing transboundary cooperation in river basin management for climate adaptation. Development Asia. https://development.asia/insight/enhancing-transboundary-cooperation-river-basin-management-climate-adaptation.

[16] Dhaubanjar, S., Lutz, A. F., Smolenaars, W. J., Khanal, S., Jamil, M. K., Biemans, H., Ludwig, F., Shrestha, A. B., & Immerzeel, W. W. (2023). Quantification of run-of-river hydropower potential in the Upper Indus basin under climate change. Frontiers in Water, 5, 1256249. https://doi.org/10.3389/frwa.2023.1256249

[17] Flores, J. A., Gleason, C. J., Brown, C., Vergopolan, N., Lummus, M. M., Stearns, L. A., Li, D., Andrews, L. C., Basnyat, D., Brinkerhoff, C. B., Ducusin, R., Feng, D., Friedmann, E., He, X., & Girotto, M. (2025). Accelerating river discharge in High Mountain Asia. AGU Advances, 24(1), e2024AV001586. https://doi.org/10.1029/2024AV001586

[18] Gao, J., Li, C., Zhou, X., Yi, Y., Wang, X., & Liu, Q. (2025). Climate change and human activities amplify runoff variability risks in lower reaches of large rivers. Communications Earth & Environment, 6(1), 794. https://doi.org/10.1038/s43247-025-02759-3

[19] Giri, I., KC, R., & Khadka, U. R. (2022). Water quality status in Bagmati River of Kathmandu Valley, Nepal. In Ecological significance of river ecosystems (Chap. 23, pp. 481–502). Elsevier. https://doi.org/10.1016/B978-0-323-85045-2.00017-0

[20] Gouli, M. R., Hu, K., Khadka, N., & Talchabhadel, R. (2023). Hazard assessment of a pair of glacial lakes in Nepal Himalaya: Unfolding combined outbursts of Upper and Lower Barun. Geomatics, Natural Hazards and Risk, 14(1), 2266219. https://doi.org/10.1080/19475705.2023.2266219

[21] Grill, G., Lehner, B., Thieme, M., Geenen, B., Tickner, D., Antonelli, F., Babu, S., Borrelli, P., Cheng, L., Crochetiere, H., Ehalt Macedo, H., Filgueiras, R., Goichot, M., Higgins, J., Hogan, Z., Lip, B., McClain, M. E., Meng, J., Mulligan, M., Zarfl, C. (2019). Mapping the world's free-flowing rivers. Nature, 569(7755), 215–221. https://doi.org/10.1038/s41586-019-1111-9

[22] Gupta, N., Dahal, S., Kumar, A., Kumar, C., Kumar, M., Maharjan, A., Mishra, D., Mohanty, A., Navaraj, A., Pandey, S., Prakash, A., Prasad, E., Shrestha, K., Shrestha, M. S., Subedi, R., Subedi, T., Tiwary, R., Tuladhar, R., & Unni, A. (2020). Rich water, poor people: Potential for transboundary flood management between Nepal and India. Current Research in Environmental Sustainability, 3, 100031. https://doi.org/10.1016/j.crsust.2021.100031

[23] He, B., Chang, J., Guo, A., Wang, L., Li, Z., Zhai, D., & Gao, F. (2025). Spatial and temporal runoff variability in response to climate change in alpine mountains. Journal of Hydrology, 654, 132779. https://doi.org/10.1016/j.jhydrol.2025.132779

[24] Hidalgo, H. G. (2021). Climate variability and change in Central America: What does it mean for water managers? Frontiers in Water, 2, 632739. https://doi.org/10.3389/frwa.2020.632739

[25] Hussain, A., Sarangi, G. K., Pandit, A., Ishaq, S., Mamnun, N., Ahmad, B., & Jamil, M. K. (2019). Hydropower development in the Hindu Kush Himalayan region: Issues, policies and opportunities. Renewable and Sustainable Energy Reviews, 107, 446–461. https://doi.org/10.1016/j.rser.2019.03.010

[26] ICIMOD. (2011). Glacial lakes and glacial lake outburst floods in Nepal. International Centre for Integrated Mountain Development (ICIMOD). https://lib.icimod.org/records/2kqn5-yrm13

[27] ICIMOD. (2025). Together we have more power: Status, challenges, and the potential for regional renewable energy cooperation in the Hindu Kush Himalaya. ICIMOD. https://doi.org/10.53055/ICIMOD.1090

[28] Immerzeel, W. W., van Beek, L. P. H., Konz, M., Shrestha, A. B., & Bierkens, M. F. P. (2012). Hydrological response to climate change in a glacierized catchment in the Himalayas. Climatic Change, 110(3–4), 721–736. https://doi.org/10.1007/s10584-011-0143-4

[29] Immerzeel, W. W., Lutz, A. F., Andrade, M., Bahl, A., Biemans, H., Bolch, T., Hyde, S., Brumby, S., Davies, B. J., Elmore, A. C., Emmer, A., Feng, M., Fernández, A., Haritashya, U., Kargel, J. S., Koppes, M., Kraaijenbrink, P. D. A., Kulkarni, A. V., Mayewski, P. A., … Baillie, J. E. M. (2020). Importance and vulnerability of the world's water towers. Nature, 577(7790), 364–369. https://doi.org/10.1038/s41586-019-1822-y

[30] International Crisis Group. (2024). Dammed in the Mekong: Averting an environmental catastrophe (Asia Report No. 343, 7 October 2024). International Crisis Group.

[31] Jha, A. N., Bhattarai, U., Lamichhane, M., Mehan, S., Ghimire, S., & Bhattarai, P. K. (2025). Assessing hydropower production potential with multisite hydrological modeling in the Koshi River Basin, Nepal. Energy Conversion and Management: X, 28, 101283. https://doi.org/10.1016/j.ecmx.2025.101283

[32] Joseph, G., & Shrestha, A. (2020). Glaciers, rivers, and springs: A water sector diagnostic of Nepal. World Bank Group. https://documents1.worldbank.org/curated/en/099605103232250863/pdf/P17157506ca2380d5096a90d786e1c2d560.pdf.

[33] Karki, R., ul Hasson, S., Gerlitz, L., Talchabhadel, R., Schickhoff, U., Scholten, T., & Böhner, J. (2020). Rising mean and extreme near-surface air temperature across Nepal. International Journal of Climatology, 40(4), 2445–2463. https://doi.org/10.1002/joc.6344

[34] Kuntla, S. K., Saharia, M., & Jain, S. K. (2025). The changing magnitude and timing of riverine floods in India. npj Natural Hazards, 2(1), 44. https://doi.org/10.1038/s44304-025-00099-y

[35] Llamosas, C., & Sovacool, B. K. (2021). The future of hydropower? A systematic review of the drivers, benefits and governance dynamics of transboundary dams. Renewable and Sustainable Energy Reviews, 137, 110495. https://doi.org/10.1016/j.rser.2020.110495

[36] Mani, A., Tsai, F. T. C., Kao, S. C., Naz, B. S., Ashfaq, M., & Rastogi, D. (2016). Conjunctive management of surface and groundwater resources under projected future climate change scenarios. Journal of Hydrology, 540, 397–411. https://doi.org/10.1016/j.jhydrol.2016.06.021

[37] Marahatta, S., Devkota, L. P., & Aryal, D. (2021). Impact of flow variation on hydropower projects in Budhigandaki River Basin of Nepal. Journal of Institute of Science and Technology, 26(1), 89–98. https://doi.org/10.3126/jist.v26i1.37831

[38] Moraga, J. S., Peleg, N., Fatichi, S., Molnar, P., & Burlando, P. (2021). Revealing the impacts of climate change on mountainous catchments through high-resolution modelling. Journal of Hydrology, 603, 126806. https://doi.org/10.1016/j.jhydrol.2021.126806

[39] Morris, G. L., & Fan, J. (1998). Reservoir sedimentation handbook: Design and management of dams, reservoirs, and watersheds for sustainable use. McGraw-Hill.

[40] Mulay, R. (2025). Integrated river basin management in the Hindu Kush Himalaya: Emphasising a multi-scale approach. ICIMOD. https://blog.icimod.org/cryosphere-water-risks/integrated-river-basin-management-in-the-hindu-kush-himalaya-emphasising-a-multi-scale-approach/.

[41] NEA, (2025). A year in review fiscal year 2023/24. Nepal Electricity Authority. https://www.nea.org.np/admin/assets/uploads/supportive_docs/60896609.pdf.

[42] Neupane, L., & Neupane, K. (2025). Turning water wealth into climate prosperity. My Republica. https://myrepublica.nagariknetwork.com/news/turning-water-wealth-into-climate-prosperity-80-59.html

[43] Niroula, Y. R. (2025). Nepal's hydropower landscape: Strengths, vulnerabilities, and growth; Project management update from Nepal. PM World Journal, XIV(VIII), 1–21. https://pmworldjournal.com/wp-content/uploads/2025/08/pmwj155-Aug2025-Niroula-Project-Management-Update-from-Nepal.pdf

[44] Ojha, K. P. (2020). An analysis of hydro-energy deficit in Nepal. Pravaha, 26(1), 101–108. https://doi.org/10.3126/pravaha.v26i1.41864

[45] Opperman, B. (2023). Reducing hydropower investment risk depends on minimizing social and environmental risks. Forbes. https://www.forbes.com/sites/jeffopperman/2023/12/14/investment-risk-for-hydropower-depends-on-minimizing-social-and-environmental-risks/

[46] Pandey, V. P., Babel, M. S., Shrestha, S., & Kazama, F. (2010). Vulnerability of freshwater resources in large and medium Nepalese river basins to environmental change. Water Science and Technology, 61(6), 1525–1534. https://doi.org/10.2166/wst.2010.751

[47] Pandey, V. P., Shrestha, N., Urfels, A., Ray, A., Khadka, M., Pavelic, P., McDonald, A. J., & Krupnik, T. J. (2023). Implementing conjunctive management of water resources for irrigation development: A framework applied to the Southern Plain of Western Nepal. Agricultural Water Management, 283, 108287. https://doi.org/10.1016/j.agwat.2023.108287

[48] Pokhrel, A. (2025). Melting peaks—Major challenges for the future of hydropower and economic growth in Nepal. Urja Khabar. https://www.urjakhabar.com/en/news/1805205688

[49] Pradhananga, S., Nepal, S., Kamal, S. K., & Hafeez, M. (2025). Climate change will exacerbate seasonal flow variability in the Karnali River Basin: Implications for water, energy, and agriculture sectors. Hydrology Research, 56(6), 471–491. https://doi.org/10.2166/nh.2025.193

[50] Rai, D. K., & Linkha, T. R. (2020). The Saptakoshi high dam project and its bio-physical consequences in the Arun river basin. Geographical Journal of Nepal, 13, 167–184. https://doi.org/10.3126/gjn.v13i0.28157

[51] Rampini, C. (2016). Impacts of hydropower development along the Brahmaputra River in Northeast India on the resilience of downstream communities to climate change impacts (Doctoral dissertation, University of California, Santa Cruz). https://escholarship.org/uc/item/7qv162sc.

[52] Rasul, G., & Molden, D. (2019). The global social and economic consequences of mountain cryospheric change. Frontiers in Environmental Science, 7, 467318. https://doi.org/10.3389/fenvs.2019.00091

[53] Sharma, L., Gupta, S. N., & Basnayake, S. (2021). Water sector policies and guidelines of Nepal: Review report. ADPC. https://www.adpc.net/igo/category/ID1811/doc/2022-otj7NA-ADPC-Water_Sector_Policies_and_Guidelines_of_Nepal.pdf

[54] Shin, S., Pokhrel, Y., Talchabhadel, R., & Panthi, J. (2021). Spatio-temporal dynamics of hydrologic changes in the Himalayan river basins of Nepal using high-resolution hydrological-hydrodynamic modeling. Journal of Hydrology, 598, 126209. https://doi.org/10.1016/j.jhydrol.2021.126209

[55] Shrestha, A. B., Agrawal, N. K., Alfthan, B., Bajracharya, S. R., Maréchal, J., & Oort, B. (2015). The Himalayan climate and water atlas: Impact of climate change on water resources in five of Asia's major river basins. ICIMOD. https://lib.icimod.org/record/31180

[56] Shrestha, M. (2025). Climate change threatens Nepal's hydropower future. Nepal Economic Forum (NEF). https://nepaleconomicforum.org/climate-change-threatens-nepals-hydropower-future/

[57] Shrestha, S., Neupane, S., Mohanasundaram, S., & Pandey, V. P. (2020). Mapping groundwater resiliency under climate change scenarios: A case study of Kathmandu Valley, Nepal. Environmental Research, 183, 109149. https://doi.org/10.1016/j.envres.2020.109149

[58] Singh, R., Bhattarai, N., Prajapati, A., & Shakya, S. R. (2022). Impact of variation in climatic parameters on hydropower generation: A case of hydropower project in Nepal. Heliyon, 8(12), e12240. https://doi.org/10.1016/j.heliyon.2022.e12240

[59] Stewardson, M. J., Walker, G., & Coleman, M. (2021). Hydrology of the Murray–Darling Basin. In P. J. Hocking, B. C. P. Walker, & R. J. Kingsford (Eds.), Murray-Darling Basin, Australia: Its future management (Vol. 1, Ecohydrology from Catchment to Coast) (pp. 47–73). Elsevier. https://doi.org/10.1016/B978-0-12-818152-2.00003-6

[60] Supriyasilp, T., Pongput, K., & Boonyasirikul, T. (2009). Hydropower development priority using MCDM method. Energy Policy, 37(5), 1866–1875. https://doi.org/10.1016/j.enpol.2009.01.023

[61] Talchabhadel, R., Karki, R., Thapa, B. R., Maharjan, M., & Parajuli, B. (2018). Spatio-temporal variability of extreme precipitation in Nepal. International Journal of Climatology, 38(11), 4296–4313. https://doi.org/10.1002/joc.5669

[62] Thatte, C. D. (2009). Sedimentation and sustainable use of reservoirs and river systems (ICOLD Bulletin 147). International Commission on Large Dams (ICOLD). http://www.icold-cigb.org/GB/publications/bulletins.asp

[63] Timpe, K., & Kaplan, D. (2017). The changing hydrology of a dammed Amazon. Science Advances, 3(11), e1700611. https://doi.org/10.1126/sciadv.1700611

[64] Turner, S. W. D., Ghimire, G. R., Hansen, C., Singh, D., & Kao, S. C. (2024). Hydropower capacity factors trending down in the United States. Nature Communications, 15(1), 5445. https://doi.org/10.1038/s41467-024-49553-x

[65] UNCTAD (2014). The state of commodity dependence 2014. United Nations Conference on Trade and Development. United Nations. https://unctad.org/publication/state-commodity-dependence-2014

[66] UNW (2015). Consolidated technical input from UN agencies on water and sanitation related indicators. UN-Water. https://sdgs.un.org/sites/default/files/publications/2076Consolidated%20Technical%20inputs.pdf

[67] Viviroli, D., Kummu, M., Meybeck, M., Kallio, M., & Wada, Y. (2020). Increasing dependence of lowland populations on mountain water resources. Nature Sustainability, 3(11), 917–928. https://doi.org/10.1038/s41893-020-0559-9

[68] Wang, Z., & Hu, C. (2009). Strategies for managing reservoir sedimentation. International Journal of Sediment Research, 24(4), 369–384.

[69] WECS. (2003). Water resource strategy Nepal. Water and Energy Commission Secretariat. Kathmandu, Nepal.

[70] WECS. (2010). Energy sector synopsis report, Water and Energy Commission Secretariat. Government of Nepal. http://www.wecs.gov.np/storage/listies/October2020/snyopsis.pdf

[71] WECS. (2011). Water resources of Nepal in the context of climate change 2011. Water and Energy Commission Secretariat (WECS). https://giwmscdnone.gov.np/media/pdf_upload/water-recource-climate-change_cn9bmcj.pdf

[72] WECS. (2020). National water plan - Nepal. Government of Nepal, Water and Energy Commission Secretariat, Ministry of Energy, Water Resources and Irrigation. 613097e4e9a1f_national_water_plan.pdf.

[73] WECS. (2023). Energy sector synopsis report 2023. Water and Energy Commission Secretariat, Government of Nepal. http://wecs.gov.np/source/Energy%20Synopsis%20Report%2C%202023.pdf

[74] World Bank. (2025). Enhancing the safety and resilience of dams in the context of climate change and extreme hydrological events: Technical note (Safety of dams and downstream communities series). https://hdl.handle.net/10986/43980

[75] World Commission on Dams (2000). Dams and Development: A New Framework for Decision-making - The Report of the World Commission on Dams (1st ed.). Routledge. https://doi.org/10.4324/9781315541518

[76] Wu, Y., Yin, X., Zhou, G., Bruijnzeel, L. A., Dai, A., Wang, F., Gentine, P., Zhang, G., Song, Y., & Zhou, D. (2024). Rising rainfall intensity induces spatially divergent hydrological changes within a large river basin. Nature Communications, 15(1), 823. https://doi.org/10.1038/s41467-023-44562-8

[77] Yadav, A., Sapkota, S. C., Dhungana, S., Dumre, P., & Bhattara, D. (2025). Climate change impact on hydropower: A comparative study of SWAT and BiLSTM-based river discharge forecasting in the Sunkoshi River Basin, Nepal. Bulletin of Computational Intelligence, 1(1), 89–103. https://doi.org/10.53941/bci.2025.100006

[78] Yu, Y., Yu, P., Wang, Y., Tu, X., Zhang, X., Zhang, S., Xu, L., Wang, X., Liu, Z., & Wang, B. (2020). Dependence of annual runoff coefficients on basin size and other properties in a climate transition zone from semi-humid to arid and semi-arid on the Loess Plateau, China. Journal of Hydrology, 591, 125727. https://doi.org/10.1016/j.jhydrol.2020.125727

[79] Zhang, Z. Y., & Sato, M. (2024). Conjunctive surface water and groundwater management in a multiple user environment. Environmental Economics and Policy Studies, 26(4), 803–841. https://doi.org/10.1007/s10018-024-00402-7

[80] Zhu, J., Zhang, J., Wu, H., Yi, X., & Liu, Y. (2024). Sustainability assessment of small hydropower from an ESG perspective: A case study of the Qin-Ba Mountains, China. Journal of Environmental Management, 350, 119523. https://doi.org/10.1016/j.jenvman.2023.119523.

Rights & permissions

2026 The Author(s). River published by Wiley-VCH GmbH on behalf of China Institute of Water Resources and Hydropower Research (IWHR).