Mekong Dams Monitor (Update for March 25 - 31)

 

Update for March 25-31 Notable changes on the Mekong in the last week. Visit the Monitor home for more, including Burmese, 中文, Khmer, ພາສາລາວ, ไทย, and Tiếng Việt translation.

SPOTLIGHT Tuoba Dam Filling in China Causes Low Levels Downstream Recent imagery from the Tuoba Dam in China shows that its reservoir has expanded significantly since it began filling in early February. As the reservoir fills it prevents water from flowing downstream, and this is causing significantly lower-than-usual river levels along the Thai-Lao border from Chiang Saen to Nakhon Phanom. Typically river levels along the Mekong are much higher than the long-term average at this time of year due to hydropower releases. China’s other largest dams have been slow to release water this year, likely due the Tuoba Dam filling upstream.

Where is the water? Dry season releases for hydropower production were significant throughout the basin last week with a net release of just under 1 billion cubic meters of water. The most significant releases came from Xiaowan (PRC, 166 million cubic meters), Nam Ngum 1 (LAO, 136 million cubic meters), Nam Ngum 2 (LAO, 355 million cubic meter), Nam Ngiep 1 (LAO 114 million cubic meters), Theun Hinboun Expansion (THA, 171 million cubic meter), Pleikrong (VNM, 117 million cubic meters), and Ubol Ratana (THA 155 million cubic meters).

Most Impactful Dams

River Levels River levels are very low from Chiang Saen to Nakhon Phanom. From Pakse downstream, river levels are normal and are lifted by releases from large dams in Laos, Thailand, and Vietnam. The Tonle Sap is slightly lower than normal for this time of year.

Chiang Saen Gauge Stung Treng Gauge

Weather & Wetness Most of the Mekong Basin is hotter and drier than normal for this time of year with severe dryness observed around the Tonle Sap Lake. There is much evidence to suggest a dry season drought is forming. The Mekong Delta is excessively wet due to irrigation from canals into agricultural fields as farmers prepare for the spring rice crop.

Mekong Dam Monitor in the News Voice of America highlights that uncertainty is the "new normal" for the Tonle Sap amid impacts from climate change, upstream dams, and illegal fishing. The Straits Times focuses on China's recent filling of the Tuoba Dam and impacts on the Mekong River downstream