China’s dams are worsening drought conditions downstream the Mekong River, storing and controlling up to 50 percent of its waters, experts say.
China on average contributes around 14 percent of the Mekong River’s flow, “but an annual average can be misleading,” says Brian Eyler, director of the Southeast Asia Program at U.S.-based Stimson Center, which describes itself as a non-profit, nonpartisan think tank that aims to enhance international peace and security through a combination of analysis and outreach.
Eyler said that during the monsoon season, the wettest parts of the Mekong River, which flows through China, Myanmar, Thailand, Laos, Cambodia, and Vietnam before reaching the sea, are not in China but in Laos and Vietnam’s Central Highlands. Therefore, in the monsoon season, China’s ‘contribution’ of water is actually around just 7 percent.
“But during the dry season, China’s contribution is much more because there is no rainfall happening in the lower parts of the basin, and much of the water comes from melting glaciers in its Himalaya range, so China could contribute up to 40 percent of the water to downstream reaches,” he said.
Then, in times of extreme drought, China controls to 50 percent of the water that should flow to downstream countries, he said.
So when China’s dams are in control of that much water, they are undeniably impacting drought conditions downstream, Eyler told VnExpress in an exclusive interview.
The Mekong River flows 4,880 km from its origins in Tibet, 2,130 km of it in China, where it is called Lancang. Of the 19 hydropower projects it plans on the Mekong, China has completed 11 that are already operational.
For several months now, drought has severely hurt farming and fishing communities in Laos, Thailand, Cambodia, Myanmar, and Vietnam, and many say China’s dams are to blame, exacerbating climate change impacts.
Now, halfway into the dry season, which normally starts in late November and lasts until late April the next year in southern Vietnam, the Mekong Delta, the nation’s most fertile region, rice granary and aquaculture hub, has already suffered serious drought and salinity.
According to the National Center for Hydro-Meteorological Forecasting, salinity has risen to up to four grams per liter 40-90 kilometers inland in all branches of the Mekong River in the delta.
Drought and salinity have affected 30,000 hectares of crops in the delta so far, or 7.3 percent of the 2016 figure, when 600,000 people did not have access to freshwater and 160,000 hectares of land were affected by saltwater, causing losses of VND5.5 trillion ($237 million).
In China’s hands
Explaining further the figure of 50 percent, Eyler said China’s 11 mega-dams store an enormous amount of water, as much as 47 billion cubic meters, and some of that water can be used to relieve drought.
To strengthen his point, he cited data from the non-profit, non-governmental, environmental and human rights organization, International Rivers (IR).
IR had said back in 2014, when China had just seven operational dams on the Mekong’s upstream, the country contributed 45 percent of water to the Mekong basin in the dry season.
Elyer said that in previous years, China used to release water from its dams to relieve drought in downstream areas when countries like Vietnam or Thailand called for it.
“So far I have yet to see this happen, although China claims its dams began to release water on January 24, 2020.”
He was commenting on China’s move, announced by its Foreign Minister Wang Yi on February 20 at the fifth Lancang-Mekong Cooperation Foreign Ministers’ Meeting in Vientiane, Laos.
Yi said China would help its downstream neighbors cope with a prolonged drought by releasing more water from its dams on the Mekong River, adding that it would also consider sharing hydrological information in future.
China too, has suffered from drought, but has overcome its difficulties and increased water release in the river to help downstream countries cope, Yi said.
While noting that the biggest culprit and the key player in this year’s drought is a lack of rainfall from the El Nino weather phenomenon, Eyler said that the severity of the drought is “exacerbated by the impact of upstream dams.”
“Each dam adds incremental degrees of impact to the drought. Currently 100 dams are making the drought worse off and the bigger they are and the closer they are to the sources of water, in this case in China, the bigger the impact they deliver to the drought,” Eyler said.
The Stimson Center ASEAN Infrastructure Database, released in June last year, said 102 dams have been built on the Mekong River, including 11 in China and 64 in Laos, also invested in by China. Another 64 dams are under construction.
Those dams hold back water, sediments and fish that are supposed to move downstream during the annual flooding season.
The Mekong River Commission has estimated that the volume of sediments reaching the delta will drop from 143 million tons a year in 2007 to 47 million tons in 2020 and just five million tons in 2040, with all the dams going up.
“Now we are observing an increased reoccurrence of drought in the Mekong Delta on a very frequent basis, and the droughts are becoming more and more severe. Previously, 2016 was the worst drought in recent memory, and this current drought is even worse.
“Climate change is changing the weather patterns and volume of rainfall on an annual basis and dams make things much worse than they have to be. But it doesn’t have to be this bad,” Eyler said.
‘Abnormally low’ rainfall
Concurring with Eyler on the main cause for drought difficulties in the Mekong Delta, To Van Truong, former deputy head of the Southern Institute of Water Resources Research, said the amount of rainfall during the rainy season last year “was abnormally low,” and that drought and salinity has arrived sooner and been more severe compared to previous years.
Last year, due to El Nino, Southeast Asia recorded less rainfall than normal and drought of historic levels hit most regional countries. In Vietnam, the most heavily affected areas were the southern and central regions.
Vietnam’s Ministry of Agriculture and Rural Development said last month that the rainy season arrived late last year and was shorter than usual, with rainfall 8 percent lower than normal at 1,240 mm.
Water levels in the Mekong’s sections in the delta have decreased rapidly since the dry season began in late November and are currently 2.33 meters lower than in previous years, it said.
It is expected that the water level in the Kratie station in Cambodia will be 35 percent lower than in previous years in the first two months of 2020 and storage in Lake Tonle Sap, the largest freshwater body in Southeast Asia, is now at 5.1 billion cubic meters, 15.7 billion cubic meters less than normal.
Dao Trong Tu, former deputy head of the Vietnam National Mekong Committee, said Mekong downstream countries have not been able to accurately evaluate the impacts of Chinese dams on their drought condition as China does not provide them with the operating procedures of its dams.
“The major problem is that China does not want to cooperate, and has never shared its actual data on hydropower projects,” he said.
Eyler predicted that “droughts will only recur more frequently in the future.”
However, El Nino weather patterns can be forecast and it seems that Vietnam was more prepared this year than in previous years, he noted.
“El Nino impacts can be predicted about six months before they take hold, which makes plenty of time for preparation in a country with the capacity to do so,” he said.
He highly appreciated Vietnam’s Resolution 120 issued in 2017, saying it “will be very effective if properly implemented” as it will restore nature-based processes related to the river’s natural flood cycle to the delta and help people there transition to more productive livelihoods.
The approach outlined in the resolution would help farmers in the delta adjust to rising sea levels and increased salinity intrusion.
The plan is now moving into its implementation phase and many development partners such as the Dutch, Israelis, and the Americans have signed up to support the process.
As the Mekong Delta is a major provider of food for 10 countries in Southeast Asia, it should be on top of the agenda of ASEAN, not just this year when Vietnam is the chair, but every year because the future of the Mekong River is at stake, Eyler said.
“The Mekong’s ecology and resource base is really threatened now so it’s high time for Vietnam, as the chair of ASEAN, to take this issue to the top of the agenda. Vietnam should outline the Mekong as a regional security issue because a crisis in the Mekong could undo regional stability,” he stressed.
As for the MRC, Eyler said it has conducted numerous studies that show how future dams built on the lower mainstream of the Mekong Delta and dams that already exist impact the Mekong basin at large.
The MRC Secretariat has never been able to have direct and timely access to China’s upstream dam data, but new cooperation provides an opportunity that it should take to investigate the real impacts of China’s dams and not allow China to steamroll the downstream countries with false data (on impacts of its mainstream dams), he said.
China has an outsized presence in the region and can easily dominate in its relationship with downstream countries and stakeholders through a variety of means, he added.
For his part, To Van Truong said that Vietnam’s first priority should be to save water.
Vietnam should store as much fresh water as it can, including groundwater, and upgrade the inland drainage system to make sure it could lead water to fields when needed.
In the long term, Vietnam needs to have a system to control the intrusion of saltwater at river gates, as well as a system to push water into fields during high tides, he said.
It also needs solutions to change the structure of crops and livestock in the direction of adapting to changing weather conditions and saving water.
He also suggested that Vietnam establishes close connection with other Mekong nations to build general plans that could benefit each nation in long term, with reference to MRC’s assessments of 11 Chinese mega dams’ impacts on the downstream area.
“I believe each nation has already known what they would gain and what they could lose in this situation,” he said.
In order to deal with China, the MRC could use the 1995 Mekong Agreement, which was signed by the governments of its four member countries – Cambodia, Laos, Thailand and Vietnam – with a focus on sustainable development and management of the Mekong River basin’s water and related resources.
Preparation of a long term Basin Development Plan and Strategy is a key part of the 1995 Agreement along with procedures for data sharing, water use monitoring, maintenance of flows and water quality, and the MRC could use that as a legal framework to demand for cooperation from China, Truong suggested.
Tu also proposed that Vietnam make use of the Lancang – Mekong Cooperation pact between the MRC and China to discuss issues of the Mekong River as water, economy and security are its three main planks.