Alert: 02/22/2025
A sudden release of water at dams in China will cause the Mekong River to rise 0.50 meters at Chiang Saen, Thailand on February 24.
Spotlight
New Report Highlights Dam Impacts on Cambodia’s Flooded Forests The Stung Treng Ramsar Site in northeastern Cambodia is one of the Mekong River’s most important—and most threatened—flooded forest ecosystems. The MDM team and IUCN teamed up to develop a new report, Engineering the Mekong: How Upstream Dams are Reshaping Cambodia’s Flooded Forest, which shows how upstream hydropower operations fundamentally alter dry‑season river flows, driving widespread forest die‑off and erosion in a system that depends on seasonal low water to survive.
Through combined hydrological analysis, satellite‑based dam operations tracking, remote sensing of land and vegetation change, and community observations, the report documents an 18 percent loss of flooded forest, with some hotspots losing more than half their land and tree cover since 2018. These ecological changes are closely linked to dry‑season water releases from large dams in China and Laos that keep river levels unnaturally high for months at a time.
Beyond local impacts, the findings raise broader questions for transboundary river governance, data transparency, and the geopolitics of hydropower in the Mekong Basin. The report also outlines feasible operational adjustments that could help restore critical low‑flow windows without undermining regional energy security. Read the report here.
What Happened Last Week?
- Where’s the Water: Collectively, dams throughout the basin recorded exceptionally high releases over the last two weeks, totaling an estimated 3.1 billion cubic meters. Major releases last week came from Xiaowan (PRC, 200 million cubic meters), Nuozhadu (PRC, 304 million cubic meters), Jinghong (PRC, 216 million cubic meters), Nam Ou 7 (LAO, 162 million cubic meters), Nam Ngum 2 (LAO, 709 million cubic meters), Nam Ngum 1 (LAO, 230 million cubic meters), Nam Ngiep 1 (LAO, 144 million cubic meters), and Nam Theun 2 (126 million cubic meters). Where is the water?
- River Levels: Levels throughout the Mekong are between 1 and 1.5 meters higher than the long-term average upstream dam releases. Points in the lower reaches of the Mekong are particularly higher than normal due to higher-than-normal dam releases from Laos. See how this looks.
- Where’s the Water: Collectively, dams throughout the basin recorded exceptionally high releases over the last two weeks, totaling an estimated 3.1 billion cubic meters. Major releases last week came from Xiaowan (PRC, 200 million cubic meters), Nuozhadu (PRC, 304 million cubic meters), Jinghong (PRC, 216 million cubic meters), Nam Ou 7 (LAO, 162 million cubic meters), Nam Ngum 2 (LAO, 709 million cubic meters), Nam Ngum 1 (LAO, 230 million cubic meters), Nam Ngiep 1 (LAO, 144 million cubic meters), and Nam Theun 2 (126 million cubic meters). Where is the water?
Image of the Week
Stung Treng reaches all-time high levels for this time of year.
Upstream dam releases, particularly those from China’s Xiaowan Dam, have lifted river levels at Stung Treng, Cambodia to the highest levels recorded. High river levels during the dry season provide very few benefits to the countries of the Mekong as dry season irrigation is mostly only practiced in Vietnam’s Delta. High river levels, however, do much damage to local ecosystems. For example, in the Stung Treng flooded forest trees are rapidly dying due to their root systems remaining underwater throughout most of the year. Also, local people cannot practice farming along the river’s banks during the dry season due to high and unpredictable levels, placing limits on their own food production.
Where is the Water?
How Wet is the Mekong Basin?
How Much Water is in Reservoirs by Country?
Current volume (billion cubic meters) of usable water across the 45 largest reservoirs in the Mekong Basin.
- Click or hover over icons on map for more details.
How Much Water is in the Largest Reservoirs?
- Hover over chart to track reservoir volume for any particular week during the year.
How Strong is the Floodpulse?
How Wet is the Mekong Floodplain?
Where did River Flow Come From?
What Should River Levels Be?
Chiang Saen Gauge (Thailand) [UNDER MAINTENANCE]
Stung Treng Gauge (Cambodia)
Chau Doc Gauge (Vietnam)
For more info, click Natural River Flow Models in the top menu.
How do Dams Impact Different Points along the Mainstream?
How was the Weather Last Week?
- Click on maps to expand and for more details.
For more information, click Compare Maps and Data in the top menu.
Which Dams Impacted the Most?
- Click or hover over icons on map for more details.
Reservoirs with an estimated change of more than 50 million cubic meters (m³) of water over last 7 days.
For more info, click Virtual Gauges in the top menu.
Current Reservoir Volume for 58 Dams
- Hover over reservoir bars to see current or potential volume
For more info, click Virtual Gauges in the top menu.