China Denies Lowered Mekong River Level Caused By Its Dams

[george]

China denies lowered Mekong River level caused by its dams

BANGKOK: -- China has denied that the lower water level of the Mekong River was caused by dams in China, saying that their construction had reduced the river's flow by only four per cent, according to a senior official at Chinese Embassy in Thailand.

Counsellor Chen Dehai of China's embassy in Bangkok said the accusation was baseless and incorrect. He said the water volume of Lanchang River that becomes the Mekong was only 13.5 per cent of the total.

Hydroelectric dam costruction in China had affected only 4 per cent of the overall water volume and would definitely not be the cause of the record low levels of the Mekong river as it flows through the Southeast Asian heartland.

The Lancang Jiang or Lancang River flows southward from China to Laos, Myanmar and Thailand. After leaving China, the name of the river changes to the Mekong River.

Mr Chen said he believed the dams were not to be blamed as the major cause of the problem was from the extremely low rainfalls since last year that cause the branches of Mekong River in Thailand to have insufficient water to replenish their flow into the Mekong River itself.

Meanwhile, he said, the three provinces in southwest China are also facing severe drought.

The water level of the Mekong River to its lowest in 20 years amd among the countgrries south of China the drought and the possible effects of the Chinese dams are believed to be the cause that reduces the water level in the reginal river that runs through China, Myanmar, Laos, Thailand, Cambodia and Vietnam.

According to the Mekong River Commission (MRC), more than 60 million people in the lower Mekong basin depend on the river system for food, transport and economic activity, and the river and lake system is home to the world's most valuable inland fisheries.

The record-low levels were posing a threat to water supply, navigation and irrigation.

Some agencies had accused Chinese dam operators of contributing to the low level of the Mekong by retaining water for irrigation and electricity generation.

As for the request for China to publicise its water level information to Mekong organisation, he said that China would check what agency had raised the issue and what Chinese agency had received the request.

However, China had not yet received the formal invitation letter to attend the MRC meeting early next month, he said.

China is home to eight dams that are either built or undergoing construction on the Mekong.

-- TNA 2010-03-11

[newsfooter][/newsfooter]

[Moonrakers]

I am no expert on the subject, but the title reads like an oxymoron to me.

[rainman]

Just blame it on Thaksin and make him pay billions in damages. That will solve the problem.

[johndpoole]

After the damns fill and the water gets run through the turbines ... doesn't the water continue down stream? Point being that yes they basically steal a lot of water to make a lake but then the flow should return to normal after they initially take the water to fill the lake. In time the same amount of water is lost at the end of the river when it flows into the ocean or larger river. I am certainly no expert but just not sure how a finished dam_n can continue to steal water.

[rogercw]

The lakes created by the dams will have larger surface areas than the portion of the river they replace. This will result in increased evaporation and a little less water flowing downstream.

It is my understanding that the lakes will also be used as a source of water for irrigation which if true will also reduce the flow downstream.

[Carib]

Well, it didn't really rain much now did it, so it cannot be just a dam.....

[ballpoint]

" The (Mekong) river supports one of the world’s most diverse fisheries, second only to Brazil’s Amazon River. China’s construction of dams and a navigation channel along the upper reaches of the Mekong threatens this complex ecosystem. Development of an 8-dam cascade is already well underway, with two dams completed and three currently under construction. The scheme will drastically change the river’s natural flood-drought cycle and block the transport of sediment, affecting ecosystems and the livelihoods of millions living downstream in Burma, Thailand, Laos, Cambodia and Vietnam. Impacts to water levels and fisheries have already been recorded along the Thai-Lao border".

http://www.internationalrivers.org/en/china/lancang-mekong-river

Every new dam will divert water while it is filled. Every existing dam will have water taken from its reservoir for irrigation purposes. Every existing dam will also divert water in times of drought in order to keep its reservoir at a working level.

Counsellor Chen Dehai of China's embassy in Bangkok said the accusation was baseless and incorrect. He said the water volume of Lanchang River that becomes the Mekong was only 13.5 per cent of the total...

...

Mr Chen said he believed the dams were not to be blamed as the major cause of the problem was from the extremely low rainfalls since last year that cause the branches of Mekong River in Thailand to have insufficient water to replenish their flow into the Mekong River itself.

These may be true for the stretch around Nong Khai and downstream, but are deliberately misleading for the area around Chiang Rai, one of the worst affected parts, where the vast majority of the water comes from China.

[johndpoole]

The lakes created by the dams will have larger surface areas than the portion of the river they replace. This will result in increased evaporation and a little less water flowing downstream.

It is my understanding that the lakes will also be used as a source of water for irrigation which if true will also reduce the flow downstream.

That makes sense. Didn't even think evaporation too since that water is not really moving, getting hot and such a large surface area. I am still amazed at how fast water evaporates here considering the humidity. I lived in Southern California where the heat is the same but very limited humidity and things seem to dry there just as fast as here.

[neverdie]

Just blame it on Thaksin and make him pay billions in damages. That will solve the problem.

Come on rainman, get off, theres plenty of thaksin threads running at the moment, go spew this vial crap in one of those threads and leave all that rubbish out of this, please.

[Harcourt]

Just blame it on Thaksin and make him pay billions in damages. That will solve the problem.

Or blame it on GW Bush.....he MUST be behind this evil.

[Thongkorn]

Just blame it on Thaksin and make him pay billions in damages. That will solve the problem.

Or blame it on GW Bush.....he MUST be behind this evil.

Come on, its Chinas turn to be the big bad wolf,

[astewpot]

The lakes created by the dams will have larger surface areas than the portion of the river they replace. This will result in increased evaporation and a little less water flowing downstream.

It is my understanding that the lakes will also be used as a source of water for irrigation which if true will also reduce the flow downstream.

That makes sense. Didn't even think evaporation too since that water is not really moving, getting hot and such a large surface area. I am still amazed at how fast water evaporates here considering the humidity. I lived in Southern California where the heat is the same but very limited humidity and things seem to dry there just as fast as here.

Area goes up by the power of 2. volume by the power of 3. This ofsets increased area and means less loss by evaporation. Why elephants have big ears to keep cool!

[Mosha]

Watching a recent Discovery programme on the 3 gorges dam. It has altered the whole ecology of the river. It has changed how the river flows, it's more polluted as only the surface layer is now flowing at any rate. Erosion is increasing at it's mouth because the silt conent in the water has dropped. Fish species and the Yangtse Dolphin have disappeared. Entirely possible the Mekong's ills lay at the Chinese's door.

[animatic]

It is illogical that the China dams have little or no down stream consequences.

It is also illogical that China can claim they have no down stream responsibilities too.

[Xonax]

Its not the dams in China, but the draught in southern China which is the real problem. As a compensation for the missing rainwater, the chinese farmers use the water from the river, for their fields.

[bubba]

I saw this last week in a comment to a newspaper article website. It appears that even the Governor of Yunnan admits that China is taking water from the Mekong. Perhaps Governor Hu and Counsellor Chen Dehai should get their stories straight? :

According to Chinese Assistant Foreign Minister Hu "water in the river passing through China accounted for only 13% of the total amount of water along the river."

Does Mr. Hu think that Thai people are stupid? the Mekong runs 1200 km through China, and the 200km as the border between Laos and Burma before it enters Thailand at Sop Ruak. So 13% of the water entering Thailand originates in China while 87% arises during its 200 km traverse of Laos/Burma?

I for one an offended at this intentionally misleading statement, and it is clear evidence that China has something to hide regarding their dams and consumption of Mekong water, and the current situation of the Mekong in Thailand.

And a revealing quote from Yunnan's governor earlier this week from: [link deleted]

"The Yunnan governor sent a reply saying he could not release the water to the lower part of the river because he needed to reserve water for agriculture during the dry season."

So indeed China is holding back water with all their dams for themselves while Thai and also Burmese, Lao, Cambodian, and Vietnamese people suffer the consequences.

Edited March 12, 2010 by bubba

[Latindancer]

Public statements by the communist Chinese are usually like this. Remember the Great Leap Foward, which was actually a giant leap backward, with millions starving ?

Who can we turn to for correct figures regarding water flow ?

[TerraPosse]

Firstly, the Mekong River Commission (MRC) is the regional body evaluating the impacts any developments along the river and its tributaries have and tasked to ensure "reasonable and equitable use" of the Mekong River System. Now, there are two notable countries absent from this commission, China and Myanmar. I leave you to draw your own conclusion as to why they won't participate in this endeavour.

Secondly, large dams along a river system and its tributaries do have a lasting impact and can change the local ecology sometimes drastically. The whole flow of water downstream of the dam(s) is regulated by the dams, meaning there will be very little seasonal variation. The natural cycle of high flows in the rainy seasons (with high levels of silt) and low flows during the dry season are changed. Sometimes this may initially be beneficial as far as flood protection goes. Long-term though the loss of silt deposits may cause lasting damage to agricultural land further downstream (in another country by all likelihood). Fish-stocks, breeding grounds and migration routes may also be severely impacted.

We were discussing this last week in a Cambodian forum as well and one of the members working on agricultural projects in the countryside pointed out that the 2008 rainy season was indeed poor but not so the 2009 rainy season. For him at least it didn't make sense blaming the 'poor' rains for the low level of the Mekong.

Edited March 12, 2010 by TerraPosse

[oldthaihand]

The lakes created by the dams will have larger surface areas than the portion of the river they replace. This will result in increased evaporation and a little less water flowing downstream.

It is my understanding that the lakes will also be used as a source of water for irrigation which if true will also reduce the flow downstream.

That makes sense. Didn't even think evaporation too since that water is not really moving, getting hot and such a large surface area. I am still amazed at how fast water evaporates here considering the humidity. I lived in Southern California where the heat is the same but very limited humidity and things seem to dry there just as fast as here.

Area goes up by the power of 2. volume by the power of 3. This ofsets increased area and means less loss by evaporation. Why elephants have big ears to keep cool!

Not sure of your logic Astewpot.

My understanding is that elephants have large ears to increase the surface area so the underlying tissues which are infused with blood carrying capillaries are able to dissipate heat to the surroundings (Usually air) at a faster rate. The only reason that this example is relevant to the subject at hand is because of the idea of increased surface area.

I agree with rogercw and johnpoole. i.e. more surface area -> increased rate of evaporation -> less water -> less flow downstream

Of course, the flow rate after the dam can be regulated. But in order to keep the water at a given height before the dam, the volume of water passing through the dam will be less than that that passed the same spot before the dam was erected.

Edited March 12, 2010 by oldthaihand

[Tejas]

The lakes created by the dams will have larger surface areas than the portion of the river they replace. This will result in increased evaporation and a little less water flowing downstream.

It is my understanding that the lakes will also be used as a source of water for irrigation which if true will also reduce the flow downstream.

That makes sense. Didn't even think evaporation too since that water is not really moving, getting hot and such a large surface area. I am still amazed at how fast water evaporates here considering the humidity. I lived in Southern California where the heat is the same but very limited humidity and things seem to dry there just as fast as here.

Area goes up by the power of 2. volume by the power of 3. This ofsets increased area and means less loss by evaporation. Why elephants have big ears to keep cool!

Evaporation is a factor but a very complicated one.

Even without a dam, increased population means increased rice production.

Increased rice production means lots of water in a large area evaporating.

Farmers also create ponds and new "streams" = more evaporation.

Increased heat from global warming means more evaporation.

The main problem......and least for the long term........is the glaciers in China that are melting and are the source of these large rivers.

Global warming = climate change = disaster (economic, social, environmental)

[tonglen]

China is about as responsible for the Dam problem as they are for the tainted melamine powdered milk.

Uh, erm, oh yeah, they were responsible for tainted milk.....

Maybe its just a case of chinese beavers......

[craigt3365]

China is about as responsible for the Dam problem as they are for the tainted melamine powdered milk.

Uh, erm, oh yeah, they were responsible for tainted milk.....

Maybe its just a case of chinese beavers......

Dang...and I have always been fond of beavers!

To see what dams do to rivers, look at the Colorado in the US. What a mess. The water, at times, never makes it to the gulf of mexico. Just dries up due to all the straws in the upriver dams....

[tonglen]

China is about as responsible for the Dam problem as they are for the tainted melamine powdered milk.

Uh, erm, oh yeah, they were responsible for tainted milk.....

Maybe its just a case of chinese beavers......

Dang...and I have always been fond of beavers!

To see what dams do to rivers, look at the Colorado in the US. What a mess. The water, at times, never makes it to the gulf of mexico. Just dries up due to all the straws in the upriver dams....

Yes, I too am a big fan of beavers, ahem, and dams do change the entire formation of rivers. In the USA, Ive done some kayaking on the Missouri River and since the Army Corps of Engineers got their little paws on it, many farmers have been affected negatively through the channelization of the river. Its helped with the transportaion of goods but hurt everything else.

[elkangorito]

Dam those Chinese!

...but some people do like 'em

Edited March 14, 2010 by elkangorito

[otherstuff1957]

Area goes up by the power of 2. volume by the power of 3. This ofsets increased area and means less loss by evaporation. Why elephants have big ears to keep cool!

That equation only works if the things being measured have the same shape. Also, evaporation occurs over time, so if you slow down the flow of the river, you will have greatly increased evaporation. As others have mentioned, the reservoirs are also used for irrigation and drinking water. All of these factors, along will lower than average rainfall will result in significantly lower water levels.

[Bizz]

I have commented on this matter illustrating a list of dams on the Mekong previously.

I will include a video we are I fear blind to so many cover-up's

it is time Greenpeace gets involved.

[LaoPo]

I saw this last week in a comment to a newspaper article website. It appears that even the Governor of Yunnan admits that China is taking water from the Mekong. Perhaps Governor Hu and Counsellor Chen Dehai should get their stories straight? :

According to Chinese Assistant Foreign Minister Hu "water in the river passing through China accounted for only 13% of the total amount of water along the river."

Does Mr. Hu think that Thai people are stupid? the Mekong runs 1200 km through China, and the 200km as the border between Laos and Burma before it enters Thailand at Sop Ruak. So 13% of the water entering Thailand originates in China while 87% arises during its 200 km traverse of Laos/Burma?

I for one an offended at this intentionally misleading statement, and it is clear evidence that China has something to hide regarding their dams and consumption of Mekong water, and the current situation of the Mekong in Thailand.

And a revealing quote from Yunnan's governor earlier this week from: [link deleted]

"The Yunnan governor sent a reply saying he could not release the water to the lower part of the river because he needed to reserve water for agriculture during the dry season."

So indeed China is holding back water with all their dams for themselves while Thai and also Burmese, Lao, Cambodian, and Vietnamese people suffer the consequences.

Many people are completely ignorant about the Mekong and yet they chose to comment with nonsense without having studied the facts; facts also published by the MRC themselves: The Mekong River Commission

The bold phrases above need comment because they are incorrect:

* The Lancang Jiang River (only later called the Mekong) runs for about 2,000 km in China, not 1,200, and has it's source in Qinghai province/China at around 5,000 meters high.

* the remainder part through all the other 5 countries is 2,800 km since the Mekong is around 4,800 km long. (there are reports claiming the river is either shorter or longer)

* The inflow of river water into the Mekong WITHIN China is not 13% but 16% -see MAP**-;

and to be clear: this chart is provided by the MRC - the Mekong River Commission.

You can see that the Mekong water supply is for 16% from China and the rest (84%) indeed from the other countries: from Myanmar: 2%, Laos: 35%, Thailand: 18%, Cambodia: 18% and Vietnam: 11%. This water is coming from thousands of small streams and smaller or larger rivers, all ending up in the Mekong.

DAMS:

There has been a lot of comment about Dams in the region and especially about the Dams in China as the cause for the water shortage in the other countries. But the droughts in Yunnan Province*** (45-50 million people) are at least as severe as in parts of Thailand.

"Yunnan has been experiencing the worst drought in six decades since last autumn due to lack of rainfall and high temperatures."

from:

http://www.chinadaily.com.cn/2010-02/25/content_9502642.htm

Yet, I hear nor see anything about Dams in Thailand...

Reservoirs and dams in Thailand (by the esteemed member Kan Win)

http://www.pbase.com/win13/dams

**

*** Drought hit villagers queue for water:

http://www.chinadaily.com.cn/photo/2010-03...ent_9524772.htm

LaoPo

[bubba]

If you look a the Bangkok Post article on 9 March 2010, it was Yunnan Governor Hu who stated that 13% of the Mekong's water comes from China. But who really knows within ±5%? He also stated that they are taking water from their dams...it is not all being released downstream.

But I do have one question for you, LaoPo: how much of the water in the Mekong comes from China when it enters Thailand? That is the percentage that matters to people in Chiang Rai.

I have to agree with the commenter who stated that Mr. Hu's mention of 13% is a feeble attempt at presenting some misleading data and China is being blatantly dishonest about the situation. Probably more than 95% of the water shared by Thailand and Laos at Chiang Saen comes from China, and all of that must pass through Chinese dams, and Governor Hu is on record as saying they are taking water from those dams.

[LaoPo]

If you look a the Bangkok Post article on 9 March 2010, it was Yunnan Governor Hu who stated that 13% of the Mekong's water comes from China. But who really knows within ±5%? He also stated that they are taking water from their dams...it is not all being released downstream.

But I do have one question for you, LaoPo: how much of the water in the Mekong comes from China when it enters Thailand? That is the percentage that matters to people in Chiang Rai.

I have to agree with the commenter who stated that Mr. Hu's mention of 13% is a feeble attempt at presenting some misleading data and China is being blatantly dishonest about the situation. Probably more than 95% of the water shared by Thailand and Laos at Chiang Saen comes from China, and all of that must pass through Chinese dams, and Governor Hu is on record as saying they are taking water from those dams.

Didn't you have a closer look at the image I included in my last post ? Why ask if I presented the map with (written) answers to you already ?

The image, with details of the water streams/inflows is presented by the Mekong River Commission.

That map is from the MRC, not China, and shows the water supply into the Lancang Jiang River, later called the Mekong when it enters Laos/Burma/Thailand, from China is 16% and not 95% as you presume.

That 95% would be silly since you forget to include all the thousands of small and larger streams/rivers that are sourced within Burma, Thailand, Laos, Cambodia and Vietnam itself and end up in the Mekong...and THAT Bubba, is a LOT of water !

But to be nice I post the map again:

Map with water supply percentages into the Mekong by 6 countries: China 16%, Myanmar: 2%, Laos: 35%, Thailand: 18%, Cambodia: 18% and Vietnam: 11%.

The MRC also published a detailed report about the present Mekong situation:

PRELIMINARY REPORT ON LOW WATER LEVEL CONDITIONS IN THE

MEKONG MAINSTREAM

5 March 2010

http://www.mrcmekong.org/download/REVISED_...lows-5mar10.pdf

You can read/see on page 2 how dramatic low the rainfall in the Upper Mekong (Lancang) has been since last year September versus the years 2008 and 2009. This results in much lower Mekong levels than normal and has nothing to do (or maybe extremely small) with the influence of the output of dams in China.

LaoPo

Edited March 14, 2010 by LaoPo

[bubba]

The Mekong runs for approximately 100 km after it leaves China (between Burma and Laos) before it enters Thailand at Sop Ruak (Chiang Saen). There are no major tributaries along that stretch. Your map shows that Burma contributes 2% of the water, and since Laos shares that same length up to that point, let's say Laos also contributes 2% along that 100 km stretch. The river is nearly dry in Chiang Saen.

So where exactly does the water come from at Chiang Saen?

Your figure of 16% obviously relates to the complete volume of water that flows into the South China Sea in Vietnam. Just as with the official Chinese statements, it is misleading and irrelevant to use that figure when discussing the amount of flow into Thailand..