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Opportunities to curb hydrological alterations via dam re-operation in the Mekong

Nature Sustainability volume 5, pages 1058–1069 (2022)Cite this article

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Abstract

In rivers around the world, hydropower development has altered the seasonal hydrological regime, which drives key ecosystem services. Dam re-operation efforts that minimize hydrological alterations are, therefore, critical to biological conservation, particularly in the tropics, where dam development is still booming. Here, we identify the limits and opportunities of alternative dam-management strategies in the Mekong, a biodiverse but rapidly developing river. We show that basin-wide efforts are needed to completely restore seasonal hydrological variability, probably an unfeasible solution in the Mekong’s institutional landscape. Instead, re-operation efforts focused on the Lower Mekong could yield tangible opportunities for partially restoring key elements of hydrological variability without affecting hydropower production. In fact, changing production plans across a few critical dams could raise Laos’ hydropower revenues by almost US$150 million per year (a third of the country’s hydropower revenues). Nexus solutions such as this one are a potential basis for safeguarding crucial economic interests and catalysing sustainable river management in international rivers.

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Fig. 1: Study site.
Fig. 2: Average annual hydropower production, firm production and deviation from natural flow conditions for 31 scenarios: BAU, MAX_MB, MAX_LMB and 28 optimized re-operation strategies.
Fig. 3: Relation between 30-day minimum and maximum flow conditions (at Stung Treng) and annual maximum flood extent in the Mekong.
Fig. 4: Flow conditions at Stung Treng under five hydrological scenarios.
Fig. 5: Performance of the Thai, Laotian and Cambodian power systems.

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Data availability

The data generated in this study have been deposited in Zenodo under the accession code https://doi.org/10.5281/zenodo.5895205.

Code availability

The hydrological water-management model VIC-Res is available at https://github.com/thanhiwer/VICRes. The implementation of the power system model (PowNet) for Thailand, Laos and Cambodia is available at https://github.com/kamal0013/PowNet.

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Acknowledgements

This research is supported by Singapore’s Ministry of Education (MoE) through the Tier 2 project ‘Linking water availability to hydropower supply—an engineering systems approach’ (award number MOE2017-T2-1-143). This manuscript was completed while M.E.A. was a McKnight Junior Faculty Fellow, sponsored by the Florida Education Fund.

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Authors and Affiliations

  1. Pillar of Engineering Systems and Design, Singapore University of Technology and Design, Singapore, Singapore

    Stefano Galelli, Thanh Duc Dang, Jia Yi Ng & A. F. M. Kamal Chowdhury

  2. Department of Civil and Environmental Engineering, University of South Florida, Tampa, FL, USA

    Thanh Duc Dang & Mauricio E. Arias

  3. Earth System Science Interdisciplinary Center, University of Maryland, College Park, MD, USA

    A. F. M. Kamal Chowdhury

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  1. Stefano Galelli
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Contributions

S.G. and M.E.A. designed the research; T.D.D., J.Y.N. and A.F.M.K.C. performed the research; T.D.D. and J.Y.N. analysed data; and S.G. and M.E.A. wrote the paper.

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Correspondence to Stefano Galelli.

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Nature Sustainability thanks Daniel Loucks, Ibrahim Nourein Mohammed and Yadu Pokhrel for their contribution to the peer review of this work.

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Galelli, S., Dang, T.D., Ng, J.Y. et al. Opportunities to curb hydrological alterations via dam re-operation in the Mekong. Nat Sustain 5, 1058–1069 (2022). https://doi.org/10.1038/s41893-022-00971-z

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