The Mekong River’s water levels have increased by nearly 1m over the last seven days from Stung Treng province to Prey Veng province’s Neak Luong. Levels are expected to further increase to nearly 3m due to heavy rainfall and dam releases upstream, the Mekong River Commission (MRC) reported.
“In Cambodia, water levels in the stretches from Stung Treng to Neak Luong in Prey Veng were reported to have increased by 0.85m,” MRC said in a press release on July 28. “In the next five days, levels are expected to increase to 2.60m.”
“Water levels in the Lower Mekong River Basin (LMB) increased significantly during the last seven days as a result of heavy rains and water releases from dams upstream. But levels across all monitoring stations are below their danger points,” it said.
Heavy rains in several areas of the LMB last week contributed to the rise, with river levels above their long-term averages, mostly at upper stations, noted the press release.
The region received in July about 40 per cent higher than average rainfall when compared to the same period between 2015 and 2020, it added.
“Due to heavy rains, dams in the lower Mekong, including those on tributaries, released a large volume of water from July 24–25, causing water levels to rise quickly,” said Lam Hung Son, head of the MRC Secretariat’s Regional Flood and Drought Management Centre, in the press release.
He added that it was not clear if these rises caused any damage.
“Sudden water releases from tributary dams pose a challenge to accurate forecasting of river levels,” Son said, noting that the MRC has installed 67 automatic hydrometeorological stations along the river and tributaries to collect rainfall and water level information.
Water from the Jinghong hydropower station in China’s Yunnan province will decrease by as much as 50 per cent due to construction, MRC quoted China’s Ministry of Water Resources as saying.
“Construction will result in a reduction of water outflow of 1,300 to 700 cubic metres per second from July 31 to August 20,”MRC quoted the ministry as saying.
The recorded outflow at the Jinghong dam on July 28 was 1,569 cubic metres per second, said MRC.
“We’re expecting a drop in water levels immediately downstream of the Jinghong dam,” Son said. “But this will also depend on the amount of rain we receive over the coming days.”
Chan Yutha, a spokesman at the Ministry of Water Resources and Meteorology, could not be reached for comment on July 28.