by Michael Lenz

www.spektrum.de/news/der-mekong-leidet-durch-chinesische-wasserkraftwerke/1738074

The sluggish Mekong has always been flowing through the wide plains in a muddy brown color. But this time it was different. At the end of 2019, in northern Thailand, the river suddenly shone in bright aquamarine. As pretty as the new color was, residents saw little reason to celebrate. An algae bloom had changed their river ﹣ another symptom of a deeper illness. The mighty Mekong is not well.

A total of 13 dams along the course of the river are the reason for the trouble. Coupled with a long drought that goes back to an El Niño, they gave the 4350 km-long river crossing six countries the lowest water level in decades. The approximately 70 million residents, who depend on the Mekong water for agriculture and fishing, are now suffering. The main beneficiary is China. Only 2 of the 13 dams are not in the People's Republic. The country is using huge dams to draw electricity from the river and plans to install at least seven more facilities. The leadership in Beijing vehemently rejects the accusation that it is at least partly to blame for the precarious situation of the Mekong.

People in the villages and communities on the banks of the river see things differently. And environmental organizations also come to a different conclusion. A study by the US research company Eyes on Earth, which specializes in the analysis of earth surface temperatures, moisture and snow cover, provides the scientific counter-evidence. "The severe water shortage in the lower Mekong during the 2019 rainy season is largely due to the limited inflow from the upper reaches of the Mekong at that time," said a report released in April 2020 and funded by the US government.

Less water arrives in the lower reaches
The effects of the eleven Chinese reservoirs, with an estimated water volume of more than 47 billion cubic meters, have long been a topic of scientific discussion. Exact statements are difficult to make due to the lack of data: Beijing does not allow its water management maps to be looked at.

Thus he researchers at Eyes on Earth used satellites to measure how wet the surface along the Lancang (that the river is called in China) was in the past. A group of scientists led by Alan Basist and Claude Williams were able to prove that the Chinese province of Yunnan even had slightly above-average rainfall and water from snowmelt during the rainy season from May to October 2019. However, the water levels in the lower reaches along the Thai-Laotian border were up to three meters lower than normal.

Measurement data were provided not only by the scouts in orbit, but also by a hydrological station of the Mekong River Commission in Chiang Saen, Thailand. It is closest to China and has recorded water levels every day since 1992. In the first 20 years, surface moisture and river water levels fluctuated in unison. That changed in 2012 when the larger Chinese dams started operating. "The difference was particularly clear in 2019," says Basist. 2019 was also the year in which the first two mega dams went into operation in Laos.

Over and over again, the Chinese promise the neighboring countries to cooperate in the management of the river. So far, however, the promises have proved hollow and empty. The Lancang-Mekong Cooperation Forum, founded in 2016, is dominated by Beijing. However, the Communist People's Republic is neither a member of the Mekong River Commission (MRC), which has existed since 1995, nor of the Lower Mekong Initiative (LMI), which the United States launched in 2009 with the other Mekong states.

The MRC has been doing a lot of scientific studies for years, issuing warnings about dams and advices on cheap ways to avoid them. But the Commission lacks power to force member states to implement the recommendations. "The Mekong River Commission has failed," said Pou Sothirak, director of the Cambodian Institute for Cooperation and Peace and former Cambodian energy minister, during a panel discussion on the Mekong's problems at the Club of Foreign Correspondents in Thailand (FCCT).

Lack of water causes empty nets
2.6 million tons of fish are caught in the Mekong in a year, says Brian Eyler of the Stimson Center in Washington. In 2019, however, the river "has dried out from the golden triangle to the delta and the natural flow of sediments and fish is missing," says the expert of the Mekong region and China's economic relations with Southeast Asia at the Thai press event. Fish is the main source of protein for people along the Mekong. Cambodia is particularly hard hit. The Khmer meet 70 percent of their protein needs by eating fish that they catch in the Mekong and in Asia's largest freshwater lake, Tonle Sap. "The Tonle Sap is the world's largest domestic fishing region and requires the entire monsoon cycle to produce this amount of fish," says Eyler. The lake used to be good for around 500,000 tons of fish. Now fishermen complained about a drop in catches of up to 70 percent.

The Tonle Sap also hangs on the Mekong. During the rainy season, the level of the river becomes so high that water is pushed into the Tonle Sap River, which forms an appendix to the lake. The direction of flow is reversed, and the upward flowing water brings fish from the upper reaches of the Mekong into the lake. This water delivery typically lasts three to four months. In 2019, however, the lake only drew water from the Mekong for about six weeks. "The breeding effect of the Tonle Sap simply didn't take place in 2019," says Eyler. This highlights another impact of the dams in Laos and China: most of the more than 850 species of fish in the Mekong are migratory fish. "But the dams block the path of the eggs and juveniles from the Mekong and its tributaries downstream into the Tonle Sap," says Eyler.

With the massive increase in the water level, Lake Tonle normally submerges half of Cambodia, flooding the country with fertile sediments, a kind of fertilizer for agriculture. That was also missing in 2019, which further increases concerns about food security in Cambodia.

Countless dams in the entire river system
In total, China, Laos, Thailand, Vietnam and Cambodia operate more than 100 dams in the entire Mekong basin. China, whose part supplies the river with 40 percent of its water during the dry season, has 11 dams, Laos has 2 plus 62 on the tributaries on the Mekong, Cambodia has 2 dams, Thailand 9 and Vietnam 16. 63 further dams are under construction in Laos. Pou Sothirak is amazed at the dam boom in the Mekong Basin. "Everyone knows that dams kill the Mekong. So why are more dams being built?" says the editor of the Journal of Greater Mekong Studies. In the first place, the dams benefit the construction companies and the politicians associated with them. "They are not interested in the social impact and damage to the environment."

This is where the geopolitical component comes into play lately, as the engagement of the US in the Mekong shows. It is less about the environment and climate, but more about competition with China for geostrategic influence in a very important region of the word. With massive financial support of billions in loans for all kinds of projects, the Middle Kingdom has kept the states on the Mekong dependent on it. Its recipe is simple: be my friend, or I will want my money back. The Chinese also use the dams to secure control of the water and, thus, life in the Mekong basin. The Association of Southeast Asian Nations (ASEAN) has so far been unable to counter this due to the lack of a Mekong policy. "For ASEAN, the increasing dominance of China on its doorstep in the South China Sea has been a priority," says Pou Sothirak.

But there are signs of changes. In February 2020, Thailand said goodbye to the Lancang-Mekong Navigation Channel Improvement Project, which has been pursued together with China, Laos and Myanmar since 2000. Rapids were to be blown up and the riverbed dredged to make the Mekong between Yunnan and the Thai-Lao border navigable for 500-ton freighters.

Can the construction boom still be stopped?
Piaporn Deetes, a Mekong expert from International Rivers Thailand, celebrates this as a victory for civil society, environmental activism and science. According to Sothirak, however, security concerns were the main reason for the government in Bangkok: "The Thais did not want to see Chinese gunboats at their border."

In March 2020, Cambodia imposed a ten-year moratorium on the construction of hydroelectric dams in its part of the Mekong, despite the fact that the country desperately needs electricity. The government in Phnom Penh now say that they want to rely on solar energy and imported coal and liquefied natural gas for electricity production, following the recommendations of a Japanese study.

Sand is becoming a scarce commodity
Another huge problem in the Mekong is illegal sand mining. According to the United Nations Environment Program (UNEP), sand is the world's most traded raw material by volume. Illegal sand export, vulgo sand smuggling, has long been a big business of the internationally operating sand mafia, which became even more lucrative due to the ban on sand exports by Cambodia and Indonesia.

The supply of sediments from the middle and upper reaches of the Mekong is already too low to compensate for sand extraction in the delta, according to a recent study by the Ludwig Franzius Institute for Hydraulic Engineering, Estuarine and Coastal Engineering (LuFI) at Leibniz University in Hanover .

When fresh sand from the north is missing, the problems caused by climate change become worse in the delta. The consequences of rising sea levels, coastal erosion and salinization of the soil could be mitigated if the Mekong continued to deposit its muddy cargo there. But now the food production of the approximately 18 million inhabitants of the delta and beyond is threatened. As the "rice bowl of Vietnam," agriculture in the Mekong Delta supplies around 50 percent of the country's food.

Powerful currents act like forces of nature that humans cannot stop. The Mekong is now in danger of becoming the first great river on earth destroyed by humans.