DPA 14 March 2010
Bangkok - The Mekong River, South-East Asia's longest waterway, is at its lowest level in 50 years, raising questions about who is to blame – mankind or Mother Nature – for the region's diminishing water supply. The 4,350-kilometre-long river originates in southern China and meanders through Laos and Thailand into Cambodia, where it feeds Tongle Sap Lake before reaching southern Vietnam and emptying into the South China Sea.
Signs that the Mekong had sunk to unusually low levels began to emerge last month when travel had to be halted on sections of the river and Vientiane, the capital of Laos, reported water shortages.
Thai non-governmental organizations were quick to point the finger at China, which has built four hydroelectric dams on the upper Mekong and plans at least six more.
They urged Thai Prime Minister Abhisit Vejjajiva to demand a clarification from Beijing on how China's dams have affected the river downstream, a connection that the Chinese government has been reluctant to investigate in the past.
The Chinese government, which has assumed a leadership role in Asia in recent years, has been quick to deny responsibility.
"Changes on the Mekong River have nothing to do with our activities," said Chen Dehai, counsellor to China's embassy in Bangkok.
Chen argued that the Chinese dams were used just for hydroelectricity production, not irrigation, and that China accounts for only 13 per cent of the water that feeds into the river.
He blamed the low river levels on unusually low rainfall in Thailand, Laos and southern China since September.
It is true rain levels in the region have been unseasonally low, causing a regionwide drought this year that is affecting southern China and most of South-East Asia.
But environmentalists and scientists still question the role of Chinese dams in the Mekong River equation and are calling for more transparency from China in ruling out a link between the two phenomena.
"This is not the first time the low water levels on the Mekong have coincided with drought and upriver dam construction in China," said Carl Middleton, the Bangkok-based International Rivers Mekong programme coordinator.
"In 1992-93 when the Chinese were constructing their first Mekong dam, the Nam Wan, it coincided with a drought and the river's level fell dramatically," Middleton said. "Did it fall because of the dam or the drought? We still don't know."
He pointed out that last year, China completed construction on the Xiao Wan Dam, which, at 300 metres high, is the biggest dam to date on the Mekong, and it began filling the reservoir in October.
A lack of data on the dam construction makes it difficult to assessits impact and separate it from other weather phenomena.
"There was a cold spell that lasted longer than usual in southern China, so the ice caps feeding the Mekong melted less," said Smith Dharasaroja, director of Thailand's Disaster Warning Foundation.
"At the same time, the Chinese have built four dams on the Upper Mekong and are building more, so maybe they tried to keep the water in the dam that is under construction," he said.
There is some evidence of a link between upriver activities and downriver water levels.
In January, the Mekong River Commission recorded a sudden 1-metre rise in the Mekong's water levels that could only be attributed to a release of large quantities of water upstream.
Regional efforts to harness the Mekong as a means of transport, source of hydroelectricity, fisheries and – most importantly – water supply have been under way for decades.
Early efforts under the old Mekong committee were hampered by the Indochina War that pitted capitalist Thailand against communist Cambodia, Laos and Vietnam on the opposite side of the river.
Those ideological differences are now largely a thing of the past.
In April 1995, a new Mekong River Commission was established with Cambodia, Laos, Thailand and Vietnam as members. A year later, China and Myanmar became dialogue partners of the organization.
A Mekong River Commission Summit was to be hosted by Thailand April 2-5 with the prime ministers of Cambodia, Laos, Thailand and Vietnam and senior representatives from China and Myanmar to attend.
Better management of the regional waterway is to be high on the agenda.
"This regional drought has been brewing since September last year," Middleton said. "Why hasn't the Mekong River Commission with all the data it collects been more forthcoming about issuing warnings on the situation if the drought was so obvious?"