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Dams will kill Mekong River downstream, say experts
Thanh Nien News. May 26, 2009.
http://www.thanhniennews.com/features/?catid=10&newsid=49157
As part of a series of eight dams on the upper half of the river,
China recently completed the Xiaowan Dam, which is the worlds tallest
at 292 meters and whose storage capacity is equal to all Southeast
Asian reservoirs combined.
Chinas extremely ambitious plan to build a massive cascade of eight
dams on the upper half of the Mekong River, as it tumbles through the
high gorges of Yunnan Province, may pose the single greatest threat to
the river, AP cited a United Nations report released last Thursday.
Ky Quang Vinh, head of the Center for Natural Resources and
Environment in the southern city of Can Tho, told Tuoi Tre newspaper
that dams are already big at heights of 15 meters.
And 292 meters is unbelievable, he said.
The Mekong River runs through six countries: China, Myanmar, Thailand,
Laos, Cambodia and Vietnam. The last four nations are also planning to
build damns on the rivers main flow through their countries.
The Mekong is being cut into pieces, Vinh said, adding that the dams
will disturb the life of fish in the river, partly by blocking their
movement.
They also pose the threat of extinction to rare fish species such as
fresh water Irrawady dolphin, the Mekong giant catfish, and numerous
other kinds of migrant fish.
The river, which is one of the highest fresh-water fish suppliers in
the world, is providing fish to more than 60 million people.
In Vietnam, the river is known as the Cuu Long River as it flows
through the southwestern region.
As the Cuu Long is the final part of the Mekong, Vinh said it will be
severely disturbed by the dams along the river, which are expected
to go beyond 20 in number.
Construction of the dams means no more profit from fish in the river
and a big drop in ecosystem-balancing creatures such as seaweed and
microorganisms, he added.
Recent statistics have shown a dramatic drop of fish in the river.
The UN report found increasing shortage of water at several river
basins such as Tonle Sap in Cambodia, Nam Khan in Laos and Sekong-
Sesan Srepok in Cambodia and Vietnam.
Ngo Dinh Tuan, scientific council chairman of the Southeast Asia
Institute of Water Resource and Environment (SAIWRE), said people
should have built the way for fish to swim through the dams.
He said the dams will retain the silt and thus, land in the downstream
area will become susceptible to land erosion and landslides.
China had started building dams on the Mekong from 1950 onwards to
bring water northward for hydropower production, Tuan said.
But according to many experts, the move aims to switch water from the
Mekong to the Yangtze River to supply water to dry areas in northern
China.
Tuan said this would mean that the Cuu Long River dries up. That will
be extremely dangerous.
Vinh also said the most visible impact of the dam construction is
severe shortage of fresh water.
Mekong Delta residents have suffered severe water shortages in the dry
season last month and will suffer more in the coming years, he said.
The water flow during the annual flooding of the river has also
reduced from 40,000 cubic meters a second in the past to 28,000 cubic
meters last October.
Farmers in the river delta had to struggle to find water for the
winter-spring crop earlier this year, Vinh said.
Coastal provinces of the delta such as Tien Giang, Ben Tre, Tra Vinh,
Soc Trang, Bac Lieu and Ca Mau have experienced saline intrusion of up
to 70 kilometers into the mainland during the dry season.
Vinh said the Chinese 292-meterhigh dam can in the long-term direct
water to dry areas in China, and be used for irrigation or hydropower
plants.
But for now, it is going to cause flooding in a large area on the dam,
which will change the local ecosystem and probably kill several rare
species in the river, he said.
According to the UN, the dam development will lead to changes in
river flow volume and timing, water quality deterioration and loss of
biodiversity.
Less fish and unpredictably changing water flows in the river will
jeopardize already difficult livelihoods for locals, Vinh said.
Vinh cites official figures saying the river generates incomes
exceeding US$3 billion a year, but adds its true value is much more as
its aquatic creatures are diverse, second only to the Amazon, and
ensures food security for dozens of millions of people.
Almost 800,000 square kilometers of the river network is home to
dozens of rare bird and marine species, including the Mekong giant
catfish, and provides food and jobs for 65 million residents in the
river basin.
The Mekong River Commission, a riparian organization on issues of
common concern, will have very little influence on this issue as long
as China and Myanmar do not join it, Tuan said.
China even argues that the river is national, not international, the
council chairman added.
The two countries also conceal their hydropower operations and such
noncooperation is dangerous, Saigon Tiep Thi newspaper on Monday
cited Dr. Le Anh Tuan from the Research Institute for Climate Change
of Can Tho University as saying.
The dam construction now joins hands with climate change to worsen
droughts, salinity intrusion, landslides and land erosion, he said.
China has built big dams on the rivers main flow while other
countries have only built them on tributaries so far, he added.
Tuan of SAIWRE said Vietnam should cooperate with international
organizations to stop upstream overexploitation of water.
We have to accept if a country builds dams for hydropower production
but have to strongly protest when the water flow is turned away.
The Vietnamese government must create a national strategy for
protecting the river downstream, not only for the Cuu Long River but
the Red River as well, Tuan said, since China has started to build
dams on it.
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