The water levels along the Mekong River in Thailand, Laos and Cambodia are set to drop due to decreased outflows at the Jinghong hydropower station in China’s Yunnan province as China conducts maintenance on its power grid infrastructure from January 5 to 24.

A statement from the inter-governmental Mekong River Commission (MRC) on January 6 announced that the maintenance would result in a reduced water flow of 1,000 cubic metres per second (m3/s) from January 5-24, citing information from China’s Ministry of Water Resources.

The flow rate will gradually return to normal from January 25, but the ministry did not specify river levels before the reduction or the volume to be restored, the statement said.

The MRC observed that the outflow level at Jinghong began decreasing from 1,410m3/s on December 31 to 768m3/s on January 1, representing a nearly 50 per cent drop. The flow rate rose slightly to 786m3/s between January 1-4.

“As a result, water levels along the Mekong River are likely to drop by about 1.2m, according to MRC’s observations and forecasting of water level data,” it said.

Water levels had already dropped by almost 2m during January 2-4 at the Chiang Saen monitoring station in Thailand, located approximately 300km downstream from Jinghong. The level is expected to rise 0.05m from January 5-11.

“In Cambodia, Mekong water levels in Stung Treng, Kratie, Kampong Cham, Phnom Penh, Koh Khel [in Kandal province] and Neak Loeung [connecting Kandal and Prey Veng provinces] did not experience any apparent decrease until January 5. The river level at these locations is expected not to change significantly, dropping only 0.03-0.07m during January 9 to 11,” the MRC said.

MRC’s Regional Flood and Drought Management Centre head Lam Hung Son said navigation activities on the Mekong River, particularly in areas near Jinghong, may be affected during this period. He said the centre will continue to monitor the situation closely.

In October, China’s water resources ministry signed an agreement with the MRC committing to share more hydrological data with Mekong countries to ensure they can prepare for potential floods and droughts.