A newly released Situation Report from the Mekong River Commission (MRC) calls for improved data sharing among the riparian nations. “We call on the six Mekong countries to increase data and information sharing on their dam and water infrastructure operations in a transparent and speedy manner with the MRC. It is time to walk the talk [sic] and to act in the common interest of the entire Mekong River Basin and the affected communities". Dr An Pich Hatda, the MRC Secretariat’s Chief Executive Officer, said 7 August.
The Mekong is Southeast Asia's longest river and acts as a lifeline to 60 million people.
The report examines hydrological conditions in the Lower Mekong Basin (LMB) between January and July 2020 and warns the six Mekong countries to address regional low water flows for the second consecutive yedar, identifying abnormal low rainfall affected by the El Nino weather patterns, carry over of low flow conditions from 2019, and lower water flow contributions from Mekong tributaries.
Combining available monitoring, rainfall and weather data, the report suggests that operation of Upper Mekong Basin (UMB) dams may have contributed the current low flow situation. Official verification is not included in the report as relevant data and information is not available.
The new report observes the low flows could have severe impact on Cambodia with loss of fisheries and additional irrigation issues. Vietnam’s rice bowl in the Mekong Delta could be adversely impacted and agricultural productivity, while Laos and Thailand will also be affected.
The report highlights the impact of low water flows on Cambodia’s Tonle Sap Lake which is the largest and most productive inland lake in Southeast Asia. As a biodiversity “hotspot”, it is the main breeding ground in the Mekong. Ecological imbalance due to disruption of timing, duration and extents of water flow could affect the reproductive cycles of fish and aquatic animals and plants in the region, leading to a threat to food security.
Cambodia, Laos, Vietnam and Thailand are urged to consider warning water users and operators of the situation to ensure water use is managed carefully. Importantly, the report suggests Member Countries to request hydropower operators and irrigation operators to adjust their near-term operations and monitor potential bank erosion.
As a last resort, if low flows persist, the four countries should consider requesting China to discharge a “water supplement”, as they did in 2016, to relieve the situation in the LMB, especially during the upcoming dry season.
The Commission's annual report, published 16 June, includes a noteworthy statement calling for increased transparency from China over upstream dam operations on the river.
MRC noted that China has previously agreed to continue providing water-level and rainfall data to the Commission during flood season, starting from June 1 until October 31, every year for five years. This near real-time data provided by China, MRC says, has enabled downstream Cambodia, Laos, Thailand and Vietnam to strengthen river water-level monitoring and improve the accuracy of flood forecasting as well as mitigate the negative effects of flooding.
The Annual Report said “While the MRC appreciates China’s sharing of the data during the flood season, it has always expressed the need to have all year-round data for effective monitoring and reporting on flood and drought, and on other emerging hydrological changes”.
China was accused in an April 2020 study of restricting water flow from 11 upstream dams, affecting approximately 60 million people live in the Lower Mekong where agriculture and fishing are the principal sources of support. Ordinarily, seasonal drought in China eventually becomes a seasonal drought in Myanmar, Thailand, Laos, Cambodia and Vietnam, while abundant water in China causes floods in the Mekong basin, as water is released from dams.