The Mekong River Commission (MRC) has expressed concern that water levels in the river have dropped significantly, changing the colour of the water in some areas, and warned that this situation could impact agricultural production and wildlife migration in Cambodia and the other countries in the region.
In a report released on February 12, the MRC detailed worrisome water levels in the Mekong between the Jinghong hydropower station in China’s Yunnan province and the delta in Vietnam.
“Water levels have dropped considerably since the beginning of the year due to lower rainfall, flow changes upstream, hydropower operations in the Mekong tributaries, and outflow restrictions from the Jinghong dam,” it said.
The drop in the water levels impacts Cambodia, Thailand, Laos and Vietnam. In Cambodia, water levels along the Mekong in Stung Treng and Kratie provinces have fluctuated slightly but remain higher than the long-term average.
According to the MRC, “river levels in Kampong Cham [province], Neak Leung [connecting Prey Veng and Svay Rieng provinces], Bassac [tributary] in Phnom Penh, and Prek Kdam [in Kandal province’s Ponhea Leu district] have been declining steadily and have remained lower than their long-term averages since November. Since January, they have seen average daily falls of 0.20m”.
Dr Winai Wangpimool, director of the MRC Secretariat’s Technical Support Division, said: “Continuing this flow pattern could have an impact on river transport, fish migration, agriculture and river weed collection.”
“To help the Lower Mekong countries manage risks more effectively, we call on China and the Lower Mekong countries themselves to share their water release plans with us,” he said.
The MRC explained that the low level of the river, combined with a slow drop in river sediments and the presence of algae on the river bottom, has resulted in the river taking on an aquamarine colour – an occurrence which happened previously in late 2019.
“Just like the situation in 2019, today’s blue-green water phenomenon is likely to spread to other stretches of the Mekong where low flows are experienced,” said MRC chief environment management officer Dr So Nam.
He said this could, in turn, affect the productivity of aquatic biodiversity, reducing fish catches and threatening the livelihoods of local communities.
Ministry of Water Resources and Meteorology spokesman Chan Yutha could not be reached for comment on February 14, but at a press conference in August last year he said the Mekong and Tonle Sap rivers were low because of the El Nino weather pattern which brought reduced rainfall.
In October, the ministry signed an agreement with the MRC committing to share data on water usage for irrigation with the other Mekong River countries as part of joint efforts to better prepare the region for floods and drought.
The MRC said that its monthly rainfall observations show that since November, rainfall has been consistently below average, falling 25 per cent.
The commission noted that the Mekong River spans 4,000km, and its tributaries support nearly 70 million people in the Lower Basin, providing livelihoods, food security and a rich ecosystem.
In early January, the MRC issued a statement expressing concern about reduced river levels due to restricted outflows from China’s Jinghong hydropower station scheduled from January 5-24 in connection with maintenance of power grid and transmission lines.
Mok Bunthoeun, an official at the NGO Forum, told The Post that the drop in the Mekong River water levels was likely to impact the agricultural sector in Cambodia. He urged the government to focus attention on solving this problem for the common good.
“The agricultural sector is impacted, and so are most Cambodians farm crops. We have seen that over the last few years, the Mekong River water level has fluctuated abnormally both during the rainy and dry seasons.
“This demands that the Cambodian government and as well as those of other regional countries meet for talks to find a proper solution to minimise possible impacts,” Bunthoeun said.