• Society

Mekong water levels sink to record low

• Thmey Thmey
• July 18, 2019 10:07 AM

MRC blames ‘very deficient rainfall’ this year and says another factor may be reduced flows from upper Mekong due to power grid maintenance in China 

PHNOM PENH — Mekong water levels since June have fallen below their historical long-term minimum levels, the Mekong River Commission (MRC) said Thursday.

“But the situation is expected to get better at the end of July,” the Vientiane-based intergovernmental agency said.

In a statement, the MRC said water levels from Laos and Thailand down to Neak Luong in Cambodia were “all below those that occurred in 1992, which was by far the year with the lowest flow on record."

At 9.31 meters, it said, the level in Kratie is about 5.40 meters below its long-term average — the average water level measured from 1961 to 2018.

But it is about 0.16 meters higher than the minimum level ever recorded, the agency said. 

‘Unprecedented’ decline

“The relatively rapid and sustained decrease in water levels and discharge from June to July 2019 has been unprecedented,” the statement said.

But “it does not reflect the natural recession of the seasonal flows when during this period the water should be slowly increasing."

Low rainfall

One of the key factors is “very deficient rainfall over the Mekong basin since the beginning of this year,” the statement said. 

Average lower-than-normal rain volume in the lower Mekong basin during June-July could also cause  deficient groundwater in the region. 

"This means there is insufficient groundwater contributing to the Mekong mainstream,” the statement said.

Less water from China

Another factor could be less water flowing from the upper part of the Mekong basin in China.

The MRC noted that China had advised that water flows out of the Jinghong hydro dam in Yunnan Province would fall from 1,050 – 1,250 cubic meters per second to 504 – 600 cubic meters per second between July 5 and 19 due to power grid maintenance.

Improved outlook

"The current state of the lower water in the basin is anticipated to improve at the end of this month, with rain in the forecast,” the statement said.

It added that wetter-than-average conditions may develop over parts of the region between the Indian and Pacific Oceans and the eastern Mekong sub-region, including the four lower Mekong countries — Cambodia, Laos, Thailand, and Vietnam — as well as Myanmar.