The Mekong River Commission (MRC) warned on August 9 that water levels in the Mekong from Stung Treng to Kratie are likely to drop significantly. The decrease is expected to be from 0.20m to 1m over the next five days.

At the same time, water levels in the lower Mekong river basin have risen sharply. This trend is expected to continue, especially from Chiang Khan to Khong Chiam in Thailand, and Vientiane to Savannakhet in Laos.

Heavy rainfall since August 5 has caused this surge. As MRC observes, river levels in most monitoring stations are now above their long-term averages.

“The region has received more than average rainfall in August alone, or approximately 40 per cent higher than it was in 2021 and 2022 during the same period,” said Sothea Khem, a flood forecasting specialist at the MRC secretariat.

Low pressure in the lower Mekong river basin has contributed to this phenomenon, Khem added.

Flash floods hit parts of Laos and Thailand particularly hard last weekend, causing water levels to rise and affecting properties and livelihoods.

In Thailand’s Chiang Khan district, water levels leapt from 7.70m to 12.26m during the first week of August.

A further rise of 0.50m is expected over the next five days, edging closer to the alarm level of 14.5m.

In Laos’ capital Vientiane, the river level increased by 4.30m during the same period, a rise of about 40 per cent. In the next five days, it is projected to rise between 2.34m and 3.32m, reaching alarm levels.

Meanwhile, from Nakhon Phanom in Thailand to Pakse in Laos, the river levels rose by more than 2.50m and are expected to increase by about 2m in the coming days. The water level at Nakhon Phanom is expected to hit its alarm level soon.

“In Cambodia, water levels from the stretches in Stung Treng to Kratie provinces increased from 0.92m to 2.59m over the same period. Over the next five days, the levels are likely to drop from 0.20m to 1m,” MRC explained in a press release.

The view under the Monivong Bridge of resident’s houses along the Tonle Bassac River in Phnom Penh’s Chamkarmon district on August 9. The Mekong River Commission has issued alerts about increasing water levels. Heng Chivoan

In Vietnam’s Mekong delta, fluctuations have been observed in water levels, but they remain lower than their long-term values, according to the MRC.

Fluctuations in water levels were also noted at China’s Jinghong hydrological station in the upper Mekong basin. Between mid-June and the end of the month, there was an average daily dip of 1.33m in the water level.

In related news, the operator of the Xayaubri Hydropower Project has warned of a possible water release from its dam. Downstream communities should be prepared for changes in river levels, according to a notification to the Lao Ministry of Energy and Mines.

The notification, dated August 7, said that due to continuous heavy rainfall in Laos, affected by Typoon Khanun and water discharge from other upstream hydropower plants, the inflow at the Xayaburi Dam has increased.

The situation across the region continues to warrant close observation and vigilance.

The Xayaubri Hydropower Project operator has warned communities both upstream and downstream of the dam to be prepared for further changes in river levels, especially for any “short notice” of water releases.

The operator reassured that it had already “activated the appropriate emergency action plan”, highlighting the seriousness of the situation and the proactive measures being taken to manage it.