By: Our Correspondent

The prime ministers of the low-lying countries through which the Mekong River runs – Thailand, Laos, Cambodia and Vietnam – have been meeting this week to attempt to reach agreement on strategies to address major challenges and opportunities facing the river’s huge basin, now and into the future, overshadowed by China, which clearly intends to exert greater influence over the river and its riparians, according to critics.

It is questionable whether any of the four, who began the meeting on April 4, demonstrate any real commitment to health of the river, which is vital to the wellbeing of 60 million people whose ancestors have for centuries relied on it for their livelihoods as well as for transport, water for cooking, irrigation, cleaning, and sanitation.

Over the past two decades, most of the four countries’ leaders have instead demonstrated a willingness to build more dams on the river because population pressures and the burgeoning thirst for additional hydropower across Southeast Asia. There is little doubt that the character of the river, Southeast Asia’s largest, is under intense stress.

The main aim of this week’s meeting, at Siem Reap in Cambodia, is a discussion of the Mekong River Council Study, a massive 3,600-page attempt to assess the impacts of mainstream hydro projects begun in 2011. The analysis includes hydropower, irrigation, agriculture and land use, transportation, domestic and industrial water use, flood protection and includes climate change. It is described as an “an integrated, cross-sectoral, comprehensive and state-of-the-art study supporting sustainable development in the Mekong Basin.”

Unfortunately, the study findings conclude that the series of 11 large hydropower dams on the lower mainstream of the river and the 120 tributary dams planned by 2040 pose a serious threat to the ecological health and economic vitality of the region.

”Major detrimental impacts resulting from current hydropower plans will in turn produce massive trade-offs between water, energy and food,” according to International Rivers, a Berkeley, Calif-based NGO dedicated to protection and preservation of the world’s rivers,  which has dealt exhaustively with the council study. “Predicted impacts include, by 2040; a 30-40 percent decrease in Mekong fisheries — a loss of about 1 million tonnes per year and a staggering 97 percent reduction in the sediment load reaching the Mekong Delta. These impacts are expected to result in a drastic reduction in food security and agricultural productivity, alongside increased poverty levels and heightened climate vulnerability in much of the Lower Mekong Basin.”

Not only are fish populations expected to fall, the study suggests that there will be drastic changes in fish species with  migratory “white fish” species predicted to disappear entirely from Thailand and Laos and being pushed to the brink in Cambodia. Invasive species are expected to take their place, putting pressure on ecosystems.

To date, decisions on hydropower projects have been made by member country governments on a project-by-project basis, without regard to basin-wide impacts. The lower Mekong governments meeting at Siem Reap “must now ensure that the findings of the Council Study meaningfully inform decisions on future projects,” according to International Rivers.

Certainly, the stakes on the river have increased. The unsettling tendency of the Chinese government to throw its weight around in the lower Mekong basin as well as its frenetic dam-building in the upper reaches, in addition to development on the mainstream of the lower delta are of rising concern. Climate change is becoming an issue as is private funding, particularly by Thai interests, of dams in Laos.

“Beijing has continued to support those countries that are determined to develop dams on the river at any cost,” according to  Mervyn Piesse, Research Manager, Global Food and Water Crises Research Program for Future Directions International, an Australian research institute. “China provides funds, materials and labor for dam construction in Laos and Cambodia. While both countries see hydroelectric dams as an integral component of their economic development, Laos plans to graduate from least-developed country status mainly by exporting surplus hydroelectricity to its neighbours. China has been willing to help fund those ambitions, as it believes that it will help to further its interests across greater South-East Asia.”

One major issue is the so-called “run-of-river” concept, generally applied to hydroper projects that have only a small reservoir or no reservoir for storing water in contrast to mega-dams that store vast amounts of water and cost billions of dollars to build. The idea is to create sustainable hydro energy while minimizing the impact on the surrounding environment and nearby communities.

The “ROR” dams are theoretically able to harness the energy potential efficiently and without a major environmental impact. Without large reservoirs, they eliminate methane and carbon dioxide emissions caused by the decomposition of organic matter in conventional reservoirs.

Proponents argue that because proposed Mekong dams have limited storage capacity, the hydrological impacts will be minimal, as they allow a ‘natural’ flow of water through the dam, thus aiding the movement downstream of sediment and allowing for the migration of fish .

But, according to International Rivers, “focusing on the overall amount of water passing through a dam does not take into account impacts on flow patterns, including increased water levels during dry season and decreased levels during wet season. The ways in which dams alter seasonal flow patterns has severe adverse implications for downstream ecosystems and agricultural systems that are built around the seasonal flood pulse.”

ROR dams can have equally harmful impacts as conventional facilities, International Rivers says, “particularly on ecosystems and communities downstream. Some of these impacts are inherent; others depend on how a dam is operated. Unfortunately, the impacts of ROR dams tend to be overlooked and understudied, an oversight in part due to the assumption that ROR are less destructive than traditional dams.”

The NGO has published a fact sheet entitled ‘Swindling the Mekong: Run-of-River Hydro’ seeking to address what it calls some of the misconceptions that surround ROR dams, and examines specific case studies in the Mekong Basin.