The launch of the Mekong Dam Monitor is likely to place further pressure on Beijing to provide timely, accurate and robust hydrological data on water levels and dam operations on the Mekong River.
After China promised to provide uninterrupted access to hydrological data on the Mekong River, Washington announced that it will also provide open access to remote sensing data related to water levels and dam operations on the river. The online Mekong Dam Monitor is hosted by the Stimson Center with funding from the State Department’s Mekong-US Partnership, which was launched in September 2020.
Beijing is critical of US research on the effects of Chinese dams on water availability in the Mekong basin. It argued that a research report from Eyes on Earth, a US-based research and consulting company, was flawed and presented a distorted view of its activities on the river. China has been reluctant to share hydrological data and, while it has promised to increase transparency, there are likely to continue to be significant gaps in its reporting.
The Eyes on Earth report, which was released in April, stated with a high degree of certainty that Chinese dams were a major factor in the severe drought that affected the lower Mekong basin in 2019. Water levels in some parts of the region declined to 50-year lows. Parts of northern Thailand experienced the lowest water levels on record, with some parts of the river drying up completely. Beijing maintains that its dams did not significantly contribute to the drought and that a very severe El Niño event was the main cause.
January-October rainfall in the lower Mekong basin was 25 per cent lower in 2019 and one-third lower in 2020, compared to 2018. There is no doubt that lower rainfall affected the region, but it is also probable that the hoarding of water in the upper portion of the river exacerbated the dry conditions. The Eyes on Earth report found that during 2019 there was an above-average amount of rainfall in the upper portion of the river but, due to the operation of dams in China, that water was prevented from flowing downstream. The report notes that China and the countries downstream of it could co-operate more closely to ensure that water flows better mimic the natural flow cycle of the river and avoid recreating the dry conditions experienced in 2019. Sharing hydrological data is the first step in that co-operation.
In November, China announced that it will share hydrological data with countries in the region at all times of the year. Previously it only shared some of that data sporadically. According to Brian Eyler, the project lead for the dam monitor at the Stimson Center, Beijing will only provide infrequent updates from the Chinese dam closest to the Thai border. China itself admits that most of the data is collected at two hydrological monitoring stations close to the Thai border. It will not provide a holistic view of hydrological conditions in the upper portion of the river, giving an incomplete picture of conditions in that part of the basin. The US dam monitor, however, will be updated weekly and will provide data on the entire Mekong basin, providing a more meaningful and useful indication of hydrological conditions.
China operates 11 dams on the upper portion of the Mekong River and aims to build another nine before 2030. Laos plans to build nine on its portion of the river, with at least another 130 planned for tributary rivers. It recently announced that it soon will begin construction of four dams on the mainstream of the river, despite crippling levels of debt with Chinese state banks. Cambodia, which is likely to be most adversely affected by the operation of all those dams (along with Vietnam), also has plans to build two dams within its borders. While it indicated that it would postpone construction of those dams, it could revive those plans at any time. A comprehensive, transparent and frequently updated view of the river system is required now more than ever.
Beijing is likely to dispute data from the US-based Mekong Dam Monitor, especially if it contradicts the data provided by Chinese hydrological monitoring stations. The US data is likely to be more robust, however, given that it is based on a more holistic view of the river than the data provided by China.