Mekong Dam Monitor (Update for April 22 - 28)

 

Update for April 22-28

Please note that the Mekong Dam Monitor platform is temporarily down, but will be restored in coming days along with all the local language and data access.

SPOTLIGHT Flooded Forest Levels are Lower Than Recent Years but Not Normal In response to last week’s Spotlight, Mekong expert Dr. Ian Baird reached out to remind us that although river levels in the flooded forest are lower than in recent years, they have not returned to a normal low level. The data confirms his point. When compared to 1910-2007, a period when large storage dams had little effect on river levels at Stung Treng, mid-April 2024 river levels in Cambodia’s flooded forest were at least 0.60m above normal. The last time river levels at the flooded forest were close to normal in mid-April was 2010 (see image), when most of the islands in the river’s channel were significantly exposed. Compare 2010 and 2024’s images to 2022, when the river saw its highest ever levels for mid-April due to major dam releases upstream. So while the current river level at Stung Treng is the lowest in 10 years, it is still far from normal and this will deliver negative ecological consequences to the flooded forest – to what degree requires further study.

Where is the water? Dry season releases for hydropower production were significant throughout the basin last week with a net release of about 1 billion cubic meters. The most significant releases came from Nam Ngum 1 (LAO, 134 million cubic meters), Theun Hinboun Expansion (LAO 155 million cubic meters), and Lower Sesan 2 (CAM 127 million cubic meters).

Most Impactful Dams

River Levels River levels are at normal or slightly higher than normal levels throughout the entirety of the Mekong. This is a rare occurrence for the dry season when upstream dam releases typically lead to river levels much higher than normal.

Chiang Saen Gauge Stung Treng Gauge

Weather & Wetness Extremely high temperatures expanded into much of Cambodia and much of Savannakhet province in Laos last week, worsening drought conditions there. Much of the basin is experiencing drought conditions. Irrigation for farming in Vietnam is still making most of the Mekong Delta extremely wet, but pockets of extreme dryness are observed along the coast particularly in Ca Mau and Bac Lieu provinces.