Mekong Dam Monitor (Update for September 2 - 8, 2024)

 

Update for September 2-8

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 August Mekong Flow: Wet extremes in the north, dry extremes in the south August brought two different realities to the Mekong Basin. Extreme precipitation in southern Yunnan, Myanmar, northern Laos, and northern Thailand raised August flow from Chiang Saen to Nakhon Phanom above normal levels. Dam restrictions in China and Laos dropped flow significantly from an extreme high down to a normal level. However those dam restrictions, combined with poor rainfall in Northeast Thailand and the 3S Basin, to drove flow downstream at Stung Treng 30% below normal. Without dam restrictions, flow at Stung Treng would have been 15% below normal and the Mekong Floodpulse would have been much stronger.

IMAGE OF THE WEEK River flow contributions from the lower basin were low in August This image shows how flow contributions from Northeast Thailand and the 3S Basin were abnormally low for August. Total estimated natural flow was also 15% lower than normal (see inset bar chart). Typically at this time of year, the lower portions of the basin contribute more water than the upper portions, sometimes accounting for more than half of all flow. But in August 2024, most flow came from central Laos (36%) and the portions of the basin above it such as northern Laos and Thailand (20%) and the China/Myanmar portion of the basin (21%).

Where is the water? Last week we observed a small cumulative restriction of flow of 344 million cubic meters throughout the basin. Major restrictions came from Xiaowan (CHN, 103 million cubic meters), Nam Ngum 1 (LAO, 201 million cubic meters).

Reservoir Storage Over Time

River Levels River levels throughout most of the Mekong are now back to below normal levels. However, rainfall and flash flooding from Typhoon Yagi will push levels upward over the coming week.

Chiang Saen Gauge Stung Treng Gauge

Weather & Wetness Some of the extreme drought conditions observed throughout the Mekong (red and orange) have been relieved by rainfall (blue/purple), but much of the basin remains in drought conditions. This map does not include effects of Typhoon Yagi which will show up on next week’s wetness map.

MDM OF THE WEEK

• Voice of America highlighted Mekong Dam Monitor analysis on the causes of recent flooding in northern Thailand