(May 28, 2009) China’s construction of big hydro-power dams on the Mekong River will be a great threat to the future of the river, a significant water source for Southeast Asia, a United Nations report said. Senior experts analysed the impacts on Vietnam’s Mekong River Delta.
According to AP, China has built eight dams on the upper Mekong River in Yunnan province. It recently finished the construction of the 292m Xiaowan Dam, the world’s highest arch dam. The UN report released on May 21 said that this dam’s capacity is equivalent to the entire capacity of all reservoirs in Southeast Asia.
At the same time, Laos has begun to build 23 dams on the lower Mekong River and its estuaries. This work is scheduled to finish in 2010.
The UN report stated that just the Xiaowan Dam alone can reduce the water volume and the running speed of water, lowering water quality and biodiversity in the Mekong River, which runs through six countries.
Young Woo Park, the UN Environment Programme director, warned the six governments to pay attention to the Mekong River, otherwise the future water resources of these countries may be threatened.
Ky Quang Vinh, director of the HCM City-based Centre for Observation of Natural Resources and the Environment, analysed the impacts of Chinese dams on the lower section of the Mekong River, particularly the Mekong River Delta of Vietnam.
He said: Dams of 15m height are quite big. It is unimaginable that the Xiaowant Dam is 292m. This dam may help draw water to serve some dry regions in China or to produce hydro-power. However, a vast area will be submerged, which will cause changes in the eco-system in this region. Some flora and fauna species may disappear, including rare ones.
The Mekong River is being cut into pieces, not only by the Xiaowan Dam in China, but dams in other countries like Laos, Thailand and Cambodia. These Southeast Asian countries plan to build 11 hydro-power dams on the main branch of the Mekong River. These dams will prevent flows of fish and cause disorder in the river, threatening the lives of millions of people who live along the river.
China’s dams on the upper Mekong River have caused serious environmental problems for the lower section like in Myanmar, northern Thailand and northern Laos. The decline of fish reserves and the change of the water level will make the lives of local people harder.
The Mekong River ranks behind only the Amazon in diversity of aquatic animals. It is one of the richest baskets of fresh-water fish in the world, which supports over 60 million people. It is estimated that the river yields income of more than $3 billion a year.
The construction of dams on the main stem of the river will threaten the extinction of rare animals, for example the Irrawaddy dolphin, Mekong giant catfish and others. Eco-regression will be a global disaster.
In Vietnam, there will be eco-changes. A huge volume of fish often moves to the Cuu Long River (the section of Mekong River in Vietnam) during the flood season. Dams prevent the flow of fish to Vietnam. In addition, ecological balance will shift. Perhaps the Mekong River Delta will not have a flood season anymore because there will not be enough water.
More dangerously, the river will be seriously short of fresh water. It happened in the recent dry season and will be more serious in the coming years. The water volume has also decreased. Measurements conducted last October showed that the flow was 28,000 cu.m per second while it was 40,000 cu.m in the past.
In the 2009 winter-spring crop, the flow of the Tien and Hau Rivers was only 1,600 cu.m per second, 100 cu.m per second less than required. In some areas in the lower section of the Cuu Long River, farmers lacked fresh water for irrigation. In coastal areas of Tien Giang, Ben Tre, Tra Vinh, Soc Trang, Bac Lieu and Ca Mau, salt water encroached 70km into the mainland.
In Vi Thanh town, Tien Giang province, for the first time the local people had to use salt water for 3-4 days continuously because tap water providers didn’t know that their sources of water were contaminated with salt water.
Prof. Ngo Dinh Tuan, chairman of the Institute for Southeast Asian Water Resources and Environment’s Scientific Council, said:
In the 1950s, China announced its strategy to move water from the south to the north. Since then they have constructed many dams on the Mekong River. These dams initially serve hydro-power production but according to many experts, they will serve to transfer water from the Mekong River to the Yangzi River and then to the dry northern region of China.
Other countries like Laos, Cambodia and Thailand are also building dams on the river. It is estimated that around 20 dams will be built on the river and these dams will greatly influence Vietnam, at the lower section of the Mekong River.
If China builds dams to serve power production, the first impact would be a remarkable reduction of aquatic resources and the volume of alluvium in the Mekong River Delta, resulting in landslides to balance the alluvial volume. It would be very dangerous for people who live in the lower section.
If China builds dams to transfer water from the Mekong River to the northern region, it would be very dangerous because the water volume going down to the lower section would be reduced considerably.
Some institutions have been established to deal with these problems, for example the Mekong River Committee of Vietnam and the International Mekong River Committee, which groups up Vietnam, Laos, Cambodia and Thailand. However, the role of these institutions is modest.
Anyways, the Mekong River Committee of Vietnam partly contributes to prevent adverse impacts on the lower section of the Mekong River. We have to take initiative in joining voices with the world in preventing countries on the upper part of the river from overexploiting water resources. We have to accept the construction of dams to produce hydroelectricity but we have to protest the transfer of water from the river to other regions, otherwise the impacts would be very serious, especially when Vietnam has to suffer from impacts of climate changes.
We need a national strategy on this issue. I think we have to build doors at the estuaries of nine branches of the Mekong River in Vietnam to prevent the encroachment of salt water. We also have to build reservoirs to stock up on water for the dry season.
This is a big issue that the government should address soon. It is not only a problem for the Cuu Long River, but the Red River as well, because China has also built dams on the upper Red River.
Dams on Mekong River
In the 1980s, China began drawing up plans to build cascade of dams on the Mekong River in its territory. China has put four of these dams into use. The construction of dams in China seriously harms the ecological environments of countries in the lower section like Myanmar, Thailand, Laos and Vietnam.
The Yunnan hydro-power information network named eight major hydro-power works which will be built on the Lancang River (Mekong River), the section running through Yunnan province. Among them, a dam named Guongguoqiao with the annual capacity of 4.04 million MW is 105m high. Geological exploration was conducted last November. China plans to store water as of June 2011.
Next to the Guongguoqiao dam is Xiaowan (19 million MW/year), which is 292m in height and will be put into operation in October 2009.
Another dam is Manwan (6.2 million MW/year), which started operating in 1993. This dam is 132m in height, and its reservoir can hold 920 million cu.m of river water.
Next to it is Daichaoshan dam (5.9 million MW/year), around 600km from Kunming city, 111m in height. It can hold 940 million cu.m of water. The dam was put into use in late 2001.
After Daichaoshan is 108m-high Jinhong dam (7.85 million MW/year). Construction was kicked off in mid 2003 and put into full operation in 2009.
Three other dams will be built from now to 2011: Nuozhado (located between Daichaoshan and Jinhong), Ganlanba and Manton.
Laos, Cambodia and Thailand also building dams
Laos, in which the Mekong River runs from the north to the south, has 23 hydro-power projects. Nine of them are located in northern Laos, including Pak Beng, Luang Prabang, Xayaboury, Pak Lay, Sanakham and Pak Chom, and Lat Sua, Donsahong and Ban Koum in the southern region. Ban Koum is the largest, with a capacity of 2,000 MW/year.
In Thailand, besides Sekamen 1 and 3 dams, the government announced it was resuming the construction of some dams on the Mekong River, worth around $11 billion, which can yield around 4,000 MW of power. According to the Bangkok Post, these dams will help provide water for agriculture in Thailand.
In the lower section of the Mekong River, Cambodia also has two hydro-power projects named Sambor and Stung Treng totalling around 3,600 MW.
VietNamNet/TT, May 28, 2009