Mekong 'cash machine' needs an overhaul

Mekong 'cash machine' needs an overhaul

Just over a week ago, many people in Thailand, particularly those in highrises, were thrown into panic when their buildings were swaying. They didn't know at the time that a strong earthquake had just hit inside Lao borders near Nan's district of Chaloem Phrakiat.

The shallow earthquake was registered at a magnitude of 5.9. This was followed shortly later by another even more powerful quake which registered at 6.4.

The quakes could be felt as far away as Bangkok, more than 700 kilometres from the epicentre near Hongsa district in Laos.

All major news outlets reported the natural event as headline news. Few took note that the massive run-of-the-river Xayaburi dam is nearby, about 40km away, and almost none mentioned the fact that the dam sits on an earth fault of its own.

About a decade ago, before construction of the dam began, several geologists sounded the alarm that building a large dam over a fault was courting disaster.

I talked to one of the geologists. Dr Punya Charusiri is a professor of geology at Chulalongkorn University and head of the Research Unit for Earthquake and Tectonics Geology of Mainland Southeast Asia.

He said the Xayaburi dam sits on what appears to be a dead or inactive fault. "But no one can guarantee that it's actually a dead fault," he added.

That's because about a decade ago there was a large quake in the hard-rock zone under the construction site. But because it happened deep in the earth, it caused little ripple on the surface. However, it was a matter of concern among geologists studying earthquakes.

One of the concerns often mentioned by opponents of big dams is that the large body of water retained by a dam exerts great pressure on the rock layers underneath it and could cause the earth to move, a phenomenon called reservoir-induced seismicity.

Could the Xayaburi dam have contributed to the recent earthquakes?

No, the geology professor said, because the quakes occurred at a different fault segment and at a relatively long distance from the dam site.

"However, what is worrying is there could be a domino effect whereby quakes at a fault segment cause nearby segments to shift," Prof Punya said.

"It's hard to say whether the fault segment over which the dam sits is an active one, but its neighbours are."

Following the latest temblors, CK Power said preliminary inspections found no damage to the Xayaburi and Nam Ngum 2 hydroelectric power plants that it operates.

Another Thai-owned power plant in Xaignabouli, the coal-fired Hongsa thermal power plant, was shut down temporarily to prevent damage. An initial survey also found no serious structural damage.

Meanwhile, another dam on the Mekong mainstream is soon to come online. The Don Sahong dam in Southern Laos' Champasak province began construction in January 2016 and is currently undergoing testing of its four turbines. Operations are expected to begin at the end of the year.

The dam is located at the southern end of the Sahong channel, one of seven major channels of the Mekong River in the Siphandone (Four Thousand Islands) area in southern Laos that flow over a geological feature called the "great fault line".

However, according to Prof Punya, there has not been a detailed geological study to determine whether the dam site is on the fault and if the fault is an active one.

"Academic studies should precede any decision to build dams or nuclear power plants, not the other way around," he said.

In its rush to become what it calls "Asia's battery", the Lao government has engaged in a frenzy of dam construction over the past 15 years. In 2005 it had nine dams. Now it operates 63 dams with 37 more under construction.

Meanwhile, nine more dam projects on the Mekong mainstream remain in the pipeline.

Few Lao people have enjoyed the benefit of these hydroelectric dams. Much of the generated electricity goes to neighbouring countries, including Thailand.

Perhaps the Lao government cannot be faulted for wanting the country to grow economically, and its many waterways present an opportunity to do just that.

However, developing the mighty Mekong River into a cash machine has caused tremendous negative impacts to the riverine ecosystem and upended livelihoods of millions of people along the river.

These are not just those inside Laos but also people in Cambodia, Vietnam and Thailand.

There are tough questions that we need to contemplate.

If we don't want Laos to over-exploit the Mekong River, which is a shared natural resource, what do we have to do to help the land-locked developing country improve its economy?

That's a question for countries of the world to crack. Specifically, rich, developed countries have an obligation to try to find an answer in the face of an escalating impact from climate change.

One particular country has greater responsibility in this regard than most.

This country has exploited the Mekong for its own benefits by building massive dams right on the river's upstream.

So far this country has refused to acknowledge its responsibility for causing massive damage to the ecosystem and deal with serious consequences suffered by people downstream.

However, we know that this country has the ability to help solve the problems as well as help Laos to achieve its economic objectives without destroying the Mekong.

The question is whether it has the moral courage to do so.

Wasant Techawongtham

Freelance Reporter

Freelance Reporter and Managing Editor of Milky Way Press.

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