How to Kill a River

How the Mekong is being destroyed and why its so hard to save

Xiaowan Dam, Lancang (upper Mekong) River, China. Credit: Credit: Guillaume Lacombe/Cirad

I recently finished

Khải Đơn

’s book of poetry, Drowning Dragon Slips by Burning Plains. I enjoyed her work but don’t often read poetry, so I’ll spare the world a ham-fisted attempt at literary analysis. However, a central theme of much of her work is nostalgia for the life-giving Mekong River Delta and the communities it nourishes. These communities are slipping away under the twin pressures of development in Vietnam’s race to prosperity and the environmental devastation affecting the Mekong at every bend in the river from its origins on the Tibetan plateau to its terminus in the South China Sea. The ecological impacts of the river’s unbridled exploitation are both devastating and larger than life. Literature has a way of helping us humanize the impacts we have on our world and can hammer home how region-wide shifts in ecology affect us at the community and personal levels.

Few issues in Southeast Asia are as pressing across the range of geopolitics, environmental stability, and community well-being as the fate of the Mekong. The Mekong shapes the entire region by flowing nearly 5000 kilometers, touching six countries, providing energy, food, and irrigation for many, and creating a transit corridor for commerce and crime. Many issues affect the Mekong, but the most alarming is the construction of mega dams on the river in China. China began damming the upper Mekong in Yunan province in the late 1990s. However, dam construction exploded after 2010 in response to China’s rapidly expanding power needs. These dams create a host of environmental issues for the Mekong. Most importantly, for the countries lower on the river, it essentially gives China a valve to control flow on the river, disrupting its natural patterns and altering flows outside of the logic the region’s irrigation and fishing patterns are based around.

For riverine states that depend on the Earth’s great rivers for their food and water supply, there are few issues more pertinent to their security than the flow of that river. That’s why some of the most contentious issues in international relations today focus on water rights for rivers and aquifers that transit international boundaries. There are few mechanisms in international law for sharing these waterways. Those with upstream control can broadly do as they’d like. Many countries will work together to create equitable water arrangements, but the dynamic always favors those upstream and with more power. In the case of the Mekong, China’s control over much of the river’s upper portion and burgeoning state power limit the ability of Southeast Asian countries to alter the situation.

How dams are changing the Mekong

The Mekong has more than a dozen dams in the Chinese portion of the river alone, but they’re not the only party negatively impacting the river. Laos has also jumped on the potential for hydroelectric power, taping Belt-and-Road initiative funds to build its own network of dams on the Mekong and its tributaries. Other countries through which the river flows are more limited in their ability to build dams due to the river’s function as an international border and also because of the flatter topography through which the river flows in its lower stretches.

Dams alter the river's flow by lowering it during the rainy season, as reservoirs are filled when the river runs high. This impact can be most dramatically seen in Cambodia on the Tonle Sap River. The Tonle Sap is a tributary that flows from central Cambodia and empties into the Mekong. However, for five months a year during the flooding season, the river reverses its flow as the Mekong’s water volume exceeds its capacity. This creates a giant lake in the center of the country that is an ideal breeding ground for fish and, throughout history, has fed the Khmer people. With reduced wet season flows on the Mekong, this cycle is now in grave danger.

Dams can also raise the flow of the river unpredictably. To produce power, dams release water downstream to spin their turbine, producing electricity. While industrial operations tend to produce consistent power demands, other aspects of society create variable demands on the grid. In particular, in the evenings, when families return home, they use power to light and heat their homes while cooking and entertaining themselves. To accommodate the urban energy needs in cities as far away as Shanghai, Chinese dams will engage in a practice called hydropeaking, where large volumes of water are released to increase the dam's power output during periods of increased demand. This can unexpectedly raise the water level downriver, creating dangers to humans, infrastructure, and the river’s fish stocks.

The shifts in water level, coupled with the physical obstructions dams create on the river, also mean less sediment washes down from the Tibetan plateau. The Mekong is a historically silty river due to its glacial origins. That silt flows downriver, contributing to the basin’s fertile agricultural land and sustaining the delta. Without that continual replenishment, the river’s delta and banks erode, wiping out vital agricultural land and displacing the communities that live there.

Of course, dams are not the only source of environmental calamity on the river. Humans alter the environment in big and small ways, with expected and unexpected consequences. Crucially, these often take the form of tradeoffs between development or commercial interests and environmental concerns.

Examples include sand dredging, the promotion of rotational rice and shrimp farming in the delta region, and the dynamiting of rocks to make the river more navigable. Such changes alter aspects of the river, such as its flow rate, erosion, and salinity of the water and soil around the river. In particular, the fragile delta region is eroding at an alarming rate due to unregulated development coupled with impacts on the river ecosystem, dams, and rising sea levels. In short, the environmental situation for the Mekong and the populations that depend on it looks increasingly desperate, driven by a combination of macro and micro factors.

Cooperative forums to manage the Mekong

International cooperation between the countries in the region on how to manage the river’s resources sustainably remains underdeveloped. Today, international efforts at river management are governed by the power disparities inherent in the relationship between China and the countries of Southeast Asia. In particular, homegrown forums to manage the river remain absent or under-invested. ASEAN has struggled to rally its focus on the Mekong, much as it has in the South China Sea. For a time, the ASEAN-Mekong Basin Development Cooperation (AMBDC) provided exactly that forum and included China. However, it was allowed to languish and has not met in a decade.

With the mothballing of AMBDC, the Mekong countries have had to rely on two foreign-born institutions. For decades, the Mekong River Commission (MRC) has provided an international framework for managing the river. It was created in the 1950s with roots in the French colonial administration and retains backing from the US and Japan. However, China never joined the MRC, leaving it impotent as a forum to discuss some of the biggest challenges facing the river. In 2016, China formed a separate governing body called the Lancang-Mekong Cooperation to facilitate cooperation. This forum at least includes all the stakeholders. However, as with Chinese diplomacy in the South China Sea, the organization emphasizes bilateral initiatives where China can exercise greater leverage over its neighbors while preventing a more comprehensive focus on the region's issues.¹ A quick tour of the Lancang-Mekong Cooperation’s website supports this, emphasizing bilateral initiatives over multilateral meetings or agreements.

The Mekong River exists as many things to the communities and nations through which it flows. It is a bread basket and a fishery, a source of electricity, a highway, and a cultural touchpoint. Because it is all of these things, the Mekong is geopolitically significant as a source of security for the populations that depend on it and, if you’re upriver, a source of leverage over those countries downstream. Sadly, because it is all of these things, its role in geopolitics and commerce will almost certainly continue to supersede the needs of the river’s fragile environment. Returning to the often melancholy tone of Drowning Dragon Slips by Burning Plains, the geopolitical state of the river today offers few solutions to the maladies facing the river and the communities that depend on it.

1. For a more thorough examination of China’s approach to diplomacy in Southeast Asia, see “Where Great Powers Meet” by David Shambaug, Chapter 5.