Vientiane Times, March 12, 2014
Water levels in the Mekong River are higher than normal, despite concern by some riverside communities in Thailand and Laos about the perceived low water level during this year’s dry season, according to river experts.
The Mekong River Commission (MRC) issued a statement on its website confirming that water levels along much of the Mekong River have been higher than normal (on long-term average) since November last year with unusual fluctuations observed in December and February.
The MRC’s statement comes after recent media reports suggested that some riverside communities along the riverine border between Thailand and Laos have raised concerns over unusual fluctuations in water levels along the Mekong, including what they consider to be lower-than-normal levels for this time of the year.
The Lao Ministry of Agriculture and Forestry said on Monday it has received no reports so far of drought elsewhere in Laos but observed that many natural rivers have maintained normal levels and conditions.
However 20 provinces in neighbouring Thailand have been declared as drought zones, Thailand’s Bangkok Post reported on Monday. The provinces are located in the north, northeast, central, east and southern regions. However, it did not say if the drought is in any way linked to the level of the Mekong.
The MRC’s data shows that water levels in the Mekong have been significantly above normal for most mainstream monitoring stations in Laos, Thailand and Cambodia since November 2013 and in many cases above the earlier highest record for this time of the year.
For example, water levels in Chiang Saen district, Chiang Rai province, in northern Thailand have almost continuously been 1.5 to 2 metres above the long-term average. Further down the Mekong in Vientiane, the water level is 1 to 1.5 metres above the average. In Kratie, Cambodia, the current water level is higher than what had consistently been observed during February and March in the past.
However, the MRC has observed unusual fluctuations in water levels and flows. As reported earlier, a sudden peak in water flows in mid-December 2013 saw water levels rise above the earlier recorded highest levels for this time of the year. This is believed to be caused by the unusually high rainfall in southern China and northern Laos.
During the first two weeks of February 2014 the water level in Chiang Saen dropped rapidly by 1 metre but the receded level was still far above the long term average. The water level then quickly returned to high levels and is currently much higher than ever recorded for this time of year.
The MRC said the rapid changes at the beginning of this year suggest the water level is influenced by human activities as there was no associated rainfall.
The unseasonably high flow and the rapid drop in water levels in the upper Mekong may be determined by water releases from cascade reservoirs on the Lancang for energy production and possibly navigation purposes.
It said local man-made activities, such as sand dredging, can change the sediment flow and morphology along certain stretches of the Mekong and can consequently cause unusually low water levels in some areas, although the water volumes remain high.