Record-low water levels have sparked widespread salinization in the Mekong Delta, leaving tens-of-thousands without adequate water supplies, experts have warned.
Local hydro-meteorologists have reported that saline water had crept 30-40 kilometers upstream from the coast, salinizing farmland that relies on the Mekong River's distributaries as their life blood.
At the same time, river water levels in An Giang were 10 centimeters below average.
The salt levels in Hau Giang Province rivers on February 26 were 3.1-5 parts per thousand and were forecasted to increase to 6-8 parts per thousand soon, while any level above one part per thousand can be damaging to rice fields.
Severe salinization was also reported in the city of Can Tho and the provinces of Tien Giang, Ben Tre, An Giang and Kien Giang.
Ngo Van Thu, chairman of Thanh Phuoc Commune People's Committee in Ben Tre, said more than 10,400 locals had to buy fresh water at VND2,000 per 40-liter can for daily use while experts expect the situation to do nothing but worsen through May.
The drying Mekong River, together with an early dry season and severe drought, has dried out a number of irrigation canals in An Giang Province's Tri Ton District that feed off the mighty waterway's distributaries. Tri Ton residents are now buying water for use in their homes and fields.
Damn those dams
At a recent conference on the Mekong River environment in Can Tho, scientists said the biggest threat to the stretch of water that supplies life and sustenance to millions was the collection of upstream hydropower dams slowly sucking it dry.
Carl Middleton, International Rivers' Mekong Program Coordinator, told the conference that the construction of dams in the Mekong would eliminate between 700,000 and 1.6 million tons of fish per year.
A report from the Saigon Giai Phong newspaper quoted Chu Thai Hoanh of the International Water Management Institute (who did not attend the above-mentioned conference) as saying that based on their designed capacity, existing and planned dams in Vietnam would use up 16 percent of the rivers' annual flow of 475 trillion liters.
Experts said the river's reduced flow was also transporting less silt and forcing Vietnamese farmers to invest more in fertilizers.
Michael Richardson, senior research fellow at the Institute of Southeast Asian Studies in Singapore, has said concerns about possible environmental impacts in the region were rising fast as China races to finish its fourth hydroelectric dam on the upper reaches of Southeast Asia's biggest river.
He said the sheer scale of China's engineering to harness the power of the Mekong and change its natural flow was setting off alarm bells, especially in Vietnam, Cambodia, Thailand and Laos, the four countries of the lower Mekong basin where more than 60 million people depend on the river for food, water and transportation.
The Mekong River Commission (MRC) has reported that the current water levels on the mainstream Mekong River are significantly below average in northern Laos and Thailand.
"Levels at mainstream measuring stations at Chiang Saen, Chiang Khan, Luang Prabang, Vientiane and Nong Khai are below those that occurred in the low flow season of 1993, which followed the most extreme regional drought on record in 1992," said the intergovernmental body that deals with all Mekong River-related activities including fisheries, agriculture and flood management.
"River tour operators have stopped offering services on the stretch of river between Houiesay and Luang Prabang in Laos and it has been reported that Yunan provincial authorities have halted the operation of Chinese cargo boats which will affect regional trade," it said.
"The flows are much lower than we've got records on in the last 20 years," Jeremy Bird, MRC secretariat chief executive officer, told AFP. "Now what we're seeing is these flows are reducing even more."
More than 60 million people in the lower Mekong basin depend on the river system for food, transport and economic activity, the MRC says, adding that it is home to the world's most valuable inland fishery.
He said 21 cargo boats have reportedly been stranded because of the shallow river water in southern China.
Officials in Laos have started advising people to reduce water consumption.
Thai non-governmental groups believe the unusually low levels are caused by Chinese dams, according to reports in the Bangkok Post.
There are eight existing or planned dams on the mainstream Mekong in China, the MRC has said.
"It's difficult for us to say categorically that there's no link" [between the low water levels and those dams], Bird said.
The Nation newspaper in Bangkok reported that Thailand will ask the MRC to negotiate with China for the release of more water from its Mekong dams to alleviate downstream drought.
Bird said the commission has not yet received any formal request from Thailand. If it does, the MRC would discuss with China the possibility of releasing water.
"This is one area where the dams upstream would actually be beneficial," he said, because once the hydropower projects are in service they should lead to 30-40 percent more dry-season water flow.