Attachments
What is happening? Exploitation of the Mekong River basin’s natural resources, especially through hydropower and sand mining, is causing escalating harm to the region’s ecosystems and endangering the livelihoods of millions of people. The effects of development are distributed unevenly, with many of the costs borne by the poor and marginalised.
Why does it matter? Environmental damage from rampant hydropower development and climate change threaten the river’s seasonal movements, supply of sediment, fish stocks and the physical security of people living along the Mekong in Cambodia, Laos, Thailand and Vietnam. These populations could be at risk of large-scale displacement.
What should be done? Policymakers should pay greater heed to the ecological value of the natural flow of the Mekong and its tributaries. They should accelerate adoption of solar and wind power. Greater transparency, data sharing and participatory decision-making – including consultation with riparian communities – in infrastructure development would improve transboundary resource governance.
Executive Summary
Environmental degradation caused by infrastructure development in the Mekong basin, especially large-scale hydropower and sand mining, threatens the region’s ecological balance and the livelihoods of 70 million people. Over the past 30 years, developers have largely ignored the natural ecosystems’ environmental and social value, while the emergence of new infrastructure and industries has deepened inequality within states. None of the Mekong basin states – China, Myanmar, Laos, Thailand, Cambodia and Vietnam – has achieved a satisfactory balance between the imperatives of economic growth and environmental preservation, while climate change has resulted in higher temperatures and severe droughts, exacerbating the harmful effects of new infrastructure. Greater understanding of environmental change is needed, with large-scale hydropower giving way to solar and wind. More effort should be invested in transboundary governance of the basin’s resources and in strengthening the participation in decision-making of the communities hardest hit by damage to the Mekong.
China’s cascade of twelve mainstream dams in the upper basin are arguably the source of the greatest environmental harm. But the countries of the lower Mekong basin – Laos, Thailand, Cambodia and Vietnam – are hardly blameless when it comes to damming rivers. Laos has staked its economic development on hydropower. There are already 75 dams on Lao tributaries, with 61 more planned, and two dams on the Mekong mainstream, with at least seven more on the drawing board. Thailand is the largest investor in Lao dams and the largest purchaser of Lao electricity. Cambodia announced a moratorium on Mekong mainstream dams in 2020, but it continues to dam tributaries. Vietnam, which bears the brunt of downstream impact of this construction, is itself an upstream dam builder, and Vietnamese public-sector companies invest in Lao dams. Sand mining, particularly in Vietnam and Cambodia, also threatens the delta, causing riverbank and coastal erosion and exacerbating salt-water intrusion.
People living along the Mekong and many of its major tributaries are already contending with irregular fluctuations in water levels, declining fish catches and the loss of traditional livelihoods. Studies and modelling point to the dire and intensifying environmental harms of hydropower and other human activity on the basin. Dams trap sediment that is crucial for nourishing soil, flora and fauna, with knock-on effects on the basin’s ecosystems and biodiversity and particularly on rice farming. Fragmentation of the river also disrupts fish migration and reproductive cycles, threatening the world’s largest freshwater fishery and endangering a vital source of protein for local communities.
Irregular flows of water and sediment pose a risk to the Mekong’s annual flood pulse, which normally sees Cambodia’s Tonle Sap Lake expand six-fold in size. This annual phenomenon is vital to sustaining Mekong fisheries, healthy wetlands and agricultural productivity. Reduced flows of water (in the wet season) and sediment also compound land subsidence and salt-water intrusion into the Mekong Delta, home to seventeen million people and Vietnam’s most productive agricultural region, most of which may be submerged by 2100.
The social and political consequences of projected environmental crises are necessarily speculative, but the worst-case scenarios are alarming. Over time, destruction of livelihoods could spur large-scale involuntary migration, boosting illicit economies, undermining government legitimacy and fomenting social discord in large parts of the lower Mekong basin.
Oversight, regulation and transnational cooperation to address the threats to the Mekong’s future are sorely missing. To the credit of the basin’s states, tensions between upstream and downstream states over water use and other conflicting interests simmer but have so far not escalated, despite the intrusion into the Mekong of major-power competition between China and the U.S. That said, cooperation among states has not always improved matters, instead often compounding environmental damage and smothering public participation in decision-making.
Shunting the costs of development onto the poor and marginalised, frequently ethnic minorities in their respective countries, has become standard practice across the Mekong. These communities, whose livelihoods and identities are bound up with the river and its tributaries, are most directly affected by environmental changes, yet largely lack the capacity to influence policy. Decision-making in the region is top-down and participatory mechanisms are weak. Civil society groups have challenged development policies and advocated for alternatives when they can, notably in Thailand, but the region’s governments have accorded them little space and given them a limited hearing.
The Mekong River Commission, the basin’s only treaty-based organisation, has no regulatory role, as its member states are unwilling to cede sovereign authority to supranational bodies. Meanwhile, states and institutions across the region have adopted the rhetoric of “sustainable development” without honouring its substance. Hydropower is being driven by governments and international networks of private enterprises and investors who are largely divorced from accountability mechanisms and local knowledge of riverine livelihoods. These actors have deep vested interests in expanding hydropower regardless of the harm caused.
The failure of governments thus far to grapple with the looming environmental catastrophe is not for lack of scientific consensus. There is broad agreement among researchers on the damage caused by large-scale hydropower as well as measures that could improve development planning and help safeguard the environment. These include ensuring participatory governance to involve local communities in decision-making; conducting research and sharing data at a basin-wide level; and accelerating adoption of solar and wind power, which are increasingly affordable and available at scale, to substitute for new hydropower. More broadly, all new development plans along the river should be informed by an appreciation of the value of the basin’s natural ecosystem and the long-term costs of harnessing nature for short-term economic gains.
A more fundamental problem is that sensible recommendations to protect the environment are meaningless without policy processes that could accommodate them. Comprehensive solutions targeting the causes of the basin’s degradation must contend not only with other priorities backed by national governments, but also constraints on the ability of states to coordinate across public and private sectors and national boundaries. Policymakers would better serve the public – not just those living alongside the Mekong but the many millions who depend on its resources across mainland South East Asia – by anticipating the problems of over-exploiting the river and its tributaries than by reacting to the catastrophic consequences.