Mekong at Risk: The Devastating Toll of Hydroelectric Dams
Eve Register is a Research Fellow at the Asia-Pacific Foundation and member of NATO Defence Education Enhancement Programme’s Global Threats Advisory Group
Hydropower is currently the world’s largest renewable energy source and accounts for over half of renewable electricity production globally. Dam construction skyrocketed in the late 1970s, driven by the reliability and cost-effectiveness of these projects in harnessing water power. By the decade’s end, an average of 1,500 large dams were being built each year. By 2020, however, this number had declined to about 50, as studies increasingly highlighted the potentially devastating environmental and longer-term impacts of large-scale hydropower projects, revealing the risks associated with the rapid expansion of this industry.
In recent years, global attention has turned to Asia’s Mekong River as a prime example for how this crisis may unfold. The river is nearly 5,000km long and flows from its headwaters in the Tibetan Plateau, through to China’s Yunnan province and on to Myanmar, Laos, Thailand, Cambodia before finally reaching its delta in southern Vietnam. The river is second only to the Amazon River in terms of fish biodiversity and is estimated to sustain the lives of at least 60 million people who live along its banks. The river is thus often described by energy experts as the ‘lifeblood’ of these communities.
Since the early 2000s, however, the construction of hydroelectric dams has intensified, particularly along the Chinese section of the river, known as the Lancang River. According to the Mekong River Commission, a multilateral organisation that works towards the sustainable development of the Mekong, China currently owns 12 operational dams on the mainstream of the river, while two are located in Laos and one in Cambodia. China’s drive to advance its hydroelectricity infrastructure is part of its goal to achieve carbon neutrality by 2060.
These dam-building developments have disrupted the river’s natural flow and seasonal cycles, causing a number of serious problems for those living downstream of these dams. While there are in fact hundreds more dams located along the Mekong’s tributary rivers, these dams are less of an ecological concern as they have a lesser impact on the broader flow of the river.
A 2022 documentary by Singaporean news channel CNA investigates the impact of what it calls ‘mega dams’ on the Mekong River, sharing testimonies from various communities along the river to underscore the extensive damage already inflicted. Individuals describe how their family businesses in fishing, agriculture and construction had been successful for many generations until the building of these dams disrupted the river’s natural downstream flow.
Fishermen describe how the ten boats their businesses used to take out onto the river each day have reduced to a mere two or three as the migration of fish has been disrupted and they are unable to reach their breeding areas. Farmers relate how growing crops has become extremely difficult, with sudden droughts and floods destroying their produce.
The Mekong also plays a pivotal role in supplying sediment essential for the construction of Southeast Asian communities and is particularly crucial for the development of their larger cities. Between 2003 and 2009 however, the sediment load in Thailand’s stretch of the Mekong reduced by 83%. Sudden and artificial changes in water levels are also eroding the banks of the river and destroying existing infrastructure in these communities.
Local NGOs substantiate these patterns and highlight even greater concerns. A Laotian woman living 10km downstream of the Nam Beng dam describes how she lost her 150 chickens and eight pigs to extreme flooding, was refused government compensation and then had to leave her home. Another member of the same Laotian community describes losing her home in the same flooding and then being threatened by Lao officials: “If you said that this was the water from the dam, we’ll put you in jail”. This individual describes how these officials insisted the water causing the flooding came from a natural source even though the dam had released water continuously for three days and nights just prior to the flooding.
While it was initially predicted in expert reports that downstream countries would benefit from these dams and were projected to reap $30 billion back in the early 2000s, this assessment has recently been revised to forecast that these countries will instead lose $7 billion if proposed dam projects go ahead. The ability of dams to control water flow was also intended to help downstream communities experiencing drought. However, Mekong expert Brian Eyler has emphasised that, in terms of this proposed water flow advantage, “downstream countries should not have to ask China to release water to relieve drought” and the very existence of this dynamic leaves downstream countries “at the mercy of those upstream”.
Either way, testimony from the communities in question seems to indicate that these supposed benefits have not materialised in practice and that flooding and drought periods have in fact intensified since the building of these dams. There has also been a lack of communication regarding the construction and operation of these dams, which has further exacerbated the suffering of affected downstream groups.
Communities have explained that they are not notified when upstream dams are opening and closing and they are thus unable to prepare for the changes in water level. The D.C-based Stimson Centre Mekong Dam Monitor has been set up to monitor reservoir levels and convey this crucial information to local communities and make up for a lack of communication, particularly on the Chinese side.
There also seems to be an alarming lack of due diligence performed prior to the construction of these dams. A European Parliament report found that impact assessments required by environmental laws to ensure the safety of an upcoming project are seen as “a mere formality” and that in some cases, construction began before these assessments had reached completion.
In a similar case of safety oversights, environmental activists discovered that a Chinese company’s report on the cross-border impact of a major dam project in Laos included sections copied directly from an older report on an entirely different project. This kind of shortcut in pre-construction assessments is deeply troubling, as the safety and stability of such projects are directly tied to the well-being of nearby communities. This connection was demonstrated unequivocally when a dam collapsed mid-construction in Laos back in 2018, displacing over 7,000 people, destroying dozens of villages and killing more than seventy people.
While China may be driven by its goal of carbon neutrality and Laos intends to boost its fragile economy by becoming the “battery of south-east Asia”, scientists are warning that further dam building may kill the Mekong River altogether. This would devastate the lives of the 60 million people who directly depend on the river to sustain themselves, and the many more millions who benefit indirectly from the Mekong’s resources. It would also render all the existing dam projects futile and waste the billions of dollars invested in their construction. A proposed plan to build Cambodia’s biggest dam back in 2018 was forecast to “literally kill” the Mekong River in a leaked assessment that had been commissioned for the project. The project is set to be completed by 2027 and it is unclear whether the warnings of this assessment have led to alterations in the planning of the new dam.
In reality, it is within the interests of all the countries that share the Mekong River to preserve its health. China’s priority has always been to harness the river’s hydropower potential as the river runs too fast and steep to be of any other use to its local communities. For downstream countries, the river’s natural resources, fishing capacity and transport facilitation have historically been of greater interest.
Communities must come together to reconcile these different priorities, all while safeguarding the river’s ecological health – the foundation of all the benefits the river provides. There are already a number of suggestions of alternatives to dam-building in the Mekong from energy experts, including the installation of floating solar panels in existing Mekong reservoirs. In the coming years, it will be essential to direct more time and funding into this line of research. Alternative solutions clearly exist – but is there the commitment to prioritise the Mekong’s health?
The opinions expressed are those of the contributor, not necessarily of the RSAA.
