- Thirty years after the 1995 Mekong Agreement, the treaty and the Mekong River Commission have failed to stop cumulative damage to the river from dams, sediment loss, sand mining and altered flows.
- Hydropower expansion and major projects such as Laos’s mainstream dams and Cambodia’s Funan Techo Canal are accelerating ecological decline, harming fisheries, sediment flows and the Tonle Sap–Mekong system despite consultation processes meant to prevent such impacts.
- “This is not cooperation,” the author writes of the agreement. “It is a rat race tearing the Mekong apart.”
- This post is a commentary. The views expressed are those of the author, not necessarily of Mongabay.
The 1995 Mekong Agreement was meant to be a cornerstone of cooperation for Cambodia, Laos, Thailand and Vietnam — promising equitable use, no significant harm, and joint management of the river. The Mekong River Commission was its steward, tasked with data sharing, project consultations, and protecting the basin’s health. Three decades on, the MRC’s 30-year milestone in November 2025 painted a picture of “shared prosperity.” Officials highlighted flood warnings, environmental studies, and even China’s data-sharing nods.
Despite the MRC’s claim that “working together is the only way forward” with “new solutions” to keep the Mekong a “river of life, not conflict,” this optimistic rhetoric has echoed for 30 years. In reality, the river faces “a death by a thousand cuts” — cumulative degradation from dams, sediment loss, sand mining, altered flows, and Lake Tonle Sap’s natural regulating role severely undermined — all of which the MRC’s 30-year approach has failed to stop.
The 1995 Mekong Agreement and the disasters of dam-building spree
Before 1995, the lower Mekong mainstream had zero large dams. The 1995 Agreement altered that. Laos built Xayaburi, operational since 2019, and Don Sahong, running since 2020. Those two alone sparked outrage from Cambodia and Vietnam over blocked fish routes and lost sediment. The PNPCA process, for prior notification and consultation, was supposed to lead to agreement. Instead, Laos treated objections as background noise and pushed ahead. Vietnam’s own tributary dams number 81; Laos, 75. Together, the basin’s total planned hydropower capacity is 23 gigawatts, drawing $50 billion in investments. China’s Lancang cascade led the way: 12 mainstream dams, 32 GW total capacity by 2025, starting with Manwan in the late 1990s. Beijing controls the tap upstream, releasing or holding water at will, controlling floods and alleviating droughts by design, but worsening natural floods and droughts, occasionally causing dry season floods and wet season droughts to downstream nations.
The drivers are clear and brutal. Thailand and Vietnam need power for booming cities; Laos sells it for export cash, branding itself Southeast Asia’s battery. Chinese firms build, Thai banks lend, all backed by government guarantees. It is a race where no one waits for consensus — because waiting means losing.
Its “consultation” has become a formality: notify, hear complaints, build anyway. Xayaburi’s PNPCA dragged on for years with studies showing fishery losses up to 80% for some species, yet no deal was struck. Don Sahong’s process was shorter, but the outcome was the same. Although at the highest level of authority, the MRC council members have the responsibility to resolve the conflict and reach agreement, yet no such agreement for any hydropower project has been reached. Instead, they agreed on study after study. This sets a dangerous pattern. Laos’s next projects — Luang Prabang under construction, Sanakham delayed but planned, Pak Beng slated for 2029 — follow the same script. Seven mainstream dams in the pipeline mean more irreversible cuts.
Overall assessment of costs and benefits of Lower Mekong River hydropower
Independent economic evaluation published by Oxfam, including the MRC council study, conclude that the net economic impact of lower Mekong mainstream dams is negative, with fisheries and sediment losses (totaling $17 billion or more cumulatively) outweighing power revenues. For the 11 planned mainstream dams plus tributaries, threats to the basin’s ecology could cost $7 billion annually in lost services, far exceeding the $3billion to $4 billion in hydropower gains. While Laos gains revenue, downstream Vietnam and Cambodia face disproportionate burdens, prompting calls for alternatives like solar/wind integration and better sediment management. Reports from 2024-2025 emphasize ongoing risks, urging sustainable planning to mitigate these imbalances.
Lake Tonle Sap: Fading flood pulse of a biosphere reserve
Lake Tonle Sap is the Mekong Basin’s beating heart. It swells five times in the wet season, storing floodwater; then it drains, feeding the Mekong Delta through the dry months. Article 6 of the 1995 Mekong Agreement demands cooperation to keep those natural flows intact: minimum dry-season levels and full wet-season reverse flow. The Procedures for Maintenance of Flows on the Mainstream (PMFM) spell out thresholds at stations like Kratie. Yet dams upstream trap water for power. A 2025 Nature Sustainability study shows reverse flows already down 40-50% to from 1998 to 2018. Projections hit 60% loss by 2038 if trends hold. Sand mining, rampant in Cambodia and Vietnam, deepens the riverbed further, slashing sediment flow that once rebuilt the delta. Fisheries have plunged; some areas have reported 70% drops in catches since dams blocked migrations. The delta’s coastline erodes, salt intrudes, and farms struggle. Climate change amps it all — drier dry seasons, wilder floods — while dams make buffering impossible.
The Funan Techo Canal: The complete decline of the Mekong spirit
Cambodia’s Funan Techo Canal is the boldest recent violation. With its groundbreaking in August 2024, this 180-kilometer (110-mile) waterway intersecting both main channels of the Mekong will divert Mekong flows to the Gulf of Thailand by 2028. Vietnam warns it will worsen delta salinity, cut sediment, and hit rice paddies hard. Studies from the Stimson Center project dry season flows will be reduced by 20% in some stretches. Cambodia labeled it a tributary project (which it is not) to sidestep full consultation, shared minimal data, and ignored MRC requests for feasibility reports. The commission noted the issue but did nothing to enforce or escalate. It is the same toothless response that has let dams multiply.
Successes and challenges of the Mekong River Commission
The 1995 agreement voids the veto power in the 1975 agreement with the definition that: “Prior consultation is neither a right to veto the use nor unilateral right to use water by any riparian without taking into account other riparians’ rights.” Thus, it is reasonable to consider that Laos’s blatant disregard of Cambodia’s and Vietnam’s rights, and Cambodia’s ignorance of Vietnam’s interests, violated the spirit and letters of the agreement.
The MRC’s successes are real but minor compared to its missions. It runs a flood-forecasting system that saves lives, shares data on water levels, and produced the 2021-2030 integrated strategy. The new 2026-2030 plan pushes for real-time dam info and closer China ties. Yet these tools have not stopped harm. They have often given projects a cloak of legitimacy: studies filed, consultations held, then construction begun. The commission lacks power to block or punish. China’s upstream role stays outside the fold; Myanmar’s too. Without full membership and binding rules, the agreement’s promise of basin-wide equity is hollow.
Overall verdict: A flawed foundation for sustainable Mekong management
The 1995 Mekong Agreement is not just paper — it is a solemn pledge by Cambodia, Laos, Thailand and Vietnam to share the river fairly, avoid harm, and cooperate genuinely. They signed it with eyes open, binding themselves to international law. Yet three decades later, the spirit of that treaty lies shattered. Dams rise without consensus, flows are diverted, and neighbors’ warnings are ignored. This is not cooperation; it is a rat race tearing the Mekong apart. These countries must stop exploiting the river for short-term gain and start upholding what they promised.
The agreement demands equitable use and no significant harm — obligations they are legally bound to meet. Laos must halt mainstream dam construction that ignores Cambodian and Vietnamese objections. Cambodia must recognize that the Funan Techo Canal is diverting water from two main Mekong channels, faithfully follow the PNPCA procedure and review the transboundary impact to the delta of Vietnam. All four need to enforce the consultation process as a path to agreement, not a rubber stamp. They must end the cycle of building first and talking later.
China’s upstream grip adds pressure: its dams control water and push debt through loans. The lower countries must resist that trap, refusing projects that chain them to Beijing’s terms. Falling risks turning neighbors into rivals, each grabbing what is left of the river. Instead, they should unite against this adversarial drift. Put the treaty’s spirit first: honor Tonle Sap’s flows, protect fisheries, save the Mekong Delta. Only then can they rebuild trust and show the world that signed words still matter.
Taking responsibility with a vision to the future
The Mekong countries risk making the MRC a “talk shop” that prioritizes dialogue over action, leaving the Mekong, Tonle Sap and its people to bear the heaviest costs of this sad reality. For people on the ground, the gap between rhetoric and reality is painful. Fishers in Tonle Sap villages see nets come up empty. Delta farmers watch fields turn salty. The MRC’s “shared prosperity” sounds like a distant echo when your livelihood shrinks. The agreement’s flaws — no sanctions, weak enforcement, easy loopholes — have turned it into an enabler of national grabs over collective good. Fixing it needs radical steps: mandatory arbitration, enforceable flow limits tied to Tonle Sap needs, sediment controls, upstream inclusion, and creation of a Mekong Fund, a compensatory vehicle for victims of floods and droughts in the Mekong River Basin, funded by taxes on hydropower revenue, technically possible. Without them, the MRC stays a forum for talk while the river dies. Thirty years in, Lake Tonle Sap is fast shrinking, the Mekong Delta is fast sinking, and the Mekong’s people deserve more than celebration — they deserve accountability.
Banner image: The water in Tonle Sap Lake in Cambodia, home of one of the world’s largest inland fisheries, is channeled from the Mekong and its tributary during the wet season. Image by Carolyn Cowan/Mongabay.
Pham Phan Long is the former chair of the Viet Ecology Foundation and a professional engineer and researcher specializing in Mekong River environmental protection and energy solutions.
Farmers fear displacement, drought, flooding tied to Cambodia’s Funan Techo Canal
Citations:
Ang, W. J., Park, E., Pokhrel, Y., Tran, D. D., & Loc, H. H. (2024). Dams in the Mekong: A comprehensive database, spatiotemporal distribution, and hydropower potentials. Earth System Science Data, 16(3), 1209-1228. doi:10.5194/essd-16-1209-2024
Quan, L. Q., Hackney, C. R., Vasilopoulos, G., Coulthard, T., Hung, N. N., Darby, S. E., & Parsons, D. R. (2025). Sand-mining-driven reduction in Tonle Sap Lake’s critical flood pulse. Nature Sustainability, 8(12), 1455-1466. doi:10.1038/s41893-025-01677-8
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