Mekong Dam Monitor (Update for August 19 - 25, 2024)

 

Update for August 19-25

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 Severe flooding hits Mekong tributaries in Thailand’s northern provinces Parts of Chiang Rai province recorded over 500mm of rainfall after two weeks of persistent heavy rain across northern Thailand and Laos, making this month one of the wettest Augusts on record. At Chiang Saen, the Mekong River peaked at five meters below flood stage, but this image shows severe flooding in the Ruak, Kok, and Ing tributaries of the Mekong covering about 1,580 square kilometers across Chiang Rai and Phayao provinces. The floods have caused severe damage to communities and at least four deaths. According to local people, these tributaries have not experienced such flooding since 2008. A preliminary analysis suggests that dam operations in this part of the river basin did not contribute to extra flooding, but further study is required.

PHOTO OF THE WEEK Pak Chom, Thailand is approaching flood stage The image shows a pulse of water forming from July through late August 2024 at Pak Chom, Thailand, with the greatest rise occurring last week as floodwaters from northern Thailand pass through the Mekong system. Currently the river levels at Pak Chom are about one meter above normal and one meter below flood stage. The high river levels along the Thai-Lao border will likely subside over the coming week.

Where is the water? Last week we tracked a large net cumulative restriction of flow of over 1.457 billion cubic meters of water across 17 dams throughout the basin. Major restrictions came from Nam Theun 2 (LAO, 538 million cubic meters), Nam Ngum 1 (LAO, 490 million cubic meters), and Nuozhadu (CHN, 300 million cubic meters). These restrictions have a devastating effect on the Mekong’s fisheries and agricultural outputs, which rely on high river levels throughout the wet season.

Most Impactful Dams

River Levels River levels along the Thai-Lao border are high from extreme precipitation over the last two weeks. These levels are predicted to subside in the coming week, but levels in southern Laos and Cambodia will rise and could push water up into the Tonle Sap Lake to boost the lake’s expansion process.

Chiang Saen Gauge Stung Treng Gauge

Weather & Wetness Despite extreme precipitation and flooding in the Golden Triangle area, most of the Mekong Basin is experiencing severe drought. The Mekong’s headwaters are extremely dry as is most of the lower basin.