Chinese dams aren’t the problem causing droughts for downstream nations along the Mekong River – they are part of the solution – says a Chinese study released in July.

The study is an attempt to pour water on claims by a rival US-backed investigation that blamed dams in China for water shortages suffered by Southeast Asian countries on the river’s lower reaches.

The Chinese study, a collaboration between Tsinghua University and China’s Institute of Water Resources, argues that the dams help alleviate the problem by storing water from the wet season and releasing it in the dry season.

The claim has sparked an academic discussion about the root cause of shortages so severe that Vietnam declared a state of emergency and Thailand enlisted its military in relief efforts.

Analysts say the competing claims are signs of a battle to control the narratives framing China’s relations with its smaller Southeast Asian neighbors, if not turning the Mekong into another front in the US-China rivalry.

Competing narratives

The Mekong, a life source for 60 million people, originates in China before running through Myanmar, Laos, Thailand, Cambodia and Vietnam.

Media reports in these downstream countries have linked the droughts to Chinese dams that use water from the Mekong’s upper reaches for domestic hydropower or irrigation. 

These claims appeared to gain weight in April when a report by the consultancy Eyes on Earth concluded that Chinese dams had been holding back 47 billion cubic meters of water.

The report was commissioned by the United Nations-backed Sustainable Infrastructure Partnership and the Lower Mekong Initiative, a partnership between the United States and all the Mekong nations bar China.

However, the Chinese study, based on the work of eight researchers led by Professor Tian Fuqiang, painted a very different picture, claiming that the droughts were due to environmental factors, including high temperatures and decreasing rainfall. 

It argued that human-made reservoirs that store water in wet seasons and release it in dry seasons, such as dams, helped with drought relief along the Mekong’s entirety and not only its upper reaches.

While the Chinese study did not explicitly mention the Eyes on Earth report, Beijing’s state-run English-language daily Global Times said Tian’s findings stood in contrast to the “reckless allegations by some foreign researchers which blamed China for the drought in countries on the lower reaches of the river.”

The Chinese study also argued that China, of all Mekong nations, faced the highest risk of a drought. It said the overall frequency of severe droughts in the Mekong was about 7%, but this reached 12% in the upper and middle sections where China’s dams are located.

A Flood of questions

Some experts and environmental groups are now questioning the findings of the Chinese report.

Marc Goichot, who leads the WWF Greater Mekong Regional Water Initiative, agreed with the Chinese assertion that irregular rainfall was a reason for the droughts. However, he said human activities also played a significant role.

Brian Eyler, director of the Southeast Asia program at Stimson Center  – a Washington-based think tank – pointed out that droughts had occurred even in the wet season and said the Chinese report had failed to address this point.

Eyler pointed to an investigation by his center that had found China’s upstream dams at Nuozhadu and Xiaowan had restricted around 20 billion cubic meters of water between July and November last year.

The investigation was based on satellite images and a public announcement by the China Southern Grid regarding the “optimization” of the dams. This suggested more droughts were on the way, he said.

“Today, satellite images show those dams are once again poised to restrict a similar amount of water from July 2020 through the end of this year … Portions of the Mekong mainstream are once again dropping to historically low levels,” Eyler said.

Out of sync with nature 

Analysts also questioned the Chinese claim that reservoirs such as dams that stored water in the wet season and released it in the dry were a viable form of drought relief for the entire Mekong region.

Eyler, the author of Last Days of the Mighty Mekong, said the changing seasons played a vital role in local ecosystems. “The natural transition from the dry to the wet season and the accompanying wet season floods produce between 15% and 20% of the world’s freshwater fish catch and underpin the economic security of all downstream countries,” said Eyler.

Meanwhile, the Thai Mekong People’s Network has described storing water for release during the dry season as being “out of sync” with nature, as floods are a natural occurrence during the rainy season.

“This is when fish and other aquatic animals swim upstream to the upper reach of the Mekong and its tributaries for spawning and reproduction,” it said in a statement to the Chinese embassy July last year detailing how the lives of people in Thailand’s eight provinces had been adversely affected by the practice.

“As the upper reach dams store water during the rainy season, less water flows downstream, upending the natural life cycle of fish, preventing water flowing into wetlands, which in turn has impacts on the people and the environment.”

It noted that the rapids, boulders and shoals that usually emerged during the dry seasons served vital ecological needs, such as providing places for millions of birds to lay their eggs. These animals had lost their habitats and had their reproduction cycles disrupted by the dams, it said.

Unseasonal fluctuations in water levels caused by the dams had also resulted in a loss of vegetation, food sources and income for local communities.

“[The dams] have even upended local cultures and traditions and deprive local people of recreational spaces,” the network added.

Gary Lee, program director of the non-profit International Rivers’ Southeast Asia group, said that contrary to the claims in the Chinese report, dams such as Jinghong, China’s most downstream dam, in Yunnan province, had reduced the amount of water released during parts of July and August last year. 

“The 11 [Chinese dams on the Mekong] have disrupted downstream flows of water, sediments and vital nutrients, which in turn have had devastating impacts on the ecosystem and aquatic resources important for communities living in the lower Mekong countries,” Lee said.

Floods can be good

Eyler said floods were historically not seen as disastrous events in the Mekong, citing a 2017 Mekong River Commission (MRC) study, which estimated that wet season flooding provided $8 billion to $10 billion in annual economic benefits while costing less than $70 million in damage. 

The MRC is an inter-government group that works to jointly manage the Mekong’s water resources on behalf of Cambodia, Laos, Thailand and Vietnam.

“As such, the benefits of natural flow outweigh the damage [of flooding] by more than 100 times. The natural flow of the Mekong River underpins the economic security of the Lower Mekong, and China’s quest to undo natural flow through upstream dam operations and exporting this dangerous discourse to the downstream will undo the stability of the Mekong region,” Eyler said.

WWF’s Goichot said storing water upstream had caused other problems by trapping sediments such as sand and gravel.

The MRC estimates that sediment loads in the river have dropped nearly 77%, compared to near-natural conditions in the early 1990s.

“As a result, the river bed of the Mekong is losing elevation … This means the delta is sinking and shrinking, further reducing the availability of freshwater supply,” Goichot said.

The MRC did agree with the Chinese report on one thing: that droughts could be expected to increase both in severity and frequency.

A way out of the battleground 

Sebastian Biba, who is the author of a book on China’s hydro-politics in the Mekong, said the conflicting reports were a sign the river had turned into a geopolitical battleground between the US and China.

The point has also been alluded to by water and energy governance firm Amperes, which in an April report said the Eyes on Earth study was not definitive and that its conclusions went beyond what the evidence suggested. 

Warning against what it called the politicization of data, it said the selective distortion or suppression of data “represents efforts from actors on all sides to influence the debate and align outcomes with their own interests.”

“Incidences of water scarcity offer strategic opportunities for stakeholders to use data to escalate or de-escalate the issue in an attempt to achieve their political ends,” the Amperes report said.

Biba said that China was not doing itself any favors with its unwillingness to share information with other countries.

“The data exists, therefore it could be shared. China’s reluctance to do so strongly suggests that the Chinese side has something to hide … It is no longer important if China actually stores water or not, the damage is already done.

“Downstream countries, regional activist groups, riparian communities, etc, they all start to distrust China and its intentions,” Biba said.

Goichot agreed, suggesting a water-level monitoring system managed by all six Mekong countries could help overcome the trust problems.

“Currently, China only shares flood season data, not data on dry season flows, nor sediment data.

“When there is no data available, this leaves room for speculation, and makes it difficult to evaluate the impact of dams on downstream flows,” Goichot said.

At a meeting of the Mekong region’s foreign ministers in February this year, China said it would consider sharing whole-year hydrological information with Mekong countries and ensure what it called a “rational and sustainable” use of water resources.