The Mekong is one of the most famous rivers on Earth. To geography buffs and Nat Geo readers, it is on par with the Nile, the Amazon and the Mississippi. To the people who live along its banks, the Mekong is a source of food, a superhighway, a laundry room and a backyard. By some estimates, as many as 240 million people make their living directly or indirectly from the river

In major cities like Bangkok, the river is becoming important not for its supply of fish or for the paddies on its banks but as a source of energy. A hydroelectric boom has come to Southeast Asia and the Mekong is its epicenter.

Shoppers inside the Siam Paragon mall

Shoppers travel around the Siam Paragon mall. The bottom floor, with the blue carpeting, is the entrance to the mall's Sea Life Bangkok Ocean World attraction. (Photo: charnsitr/Shutterstock)

A new source of clean energy   

On one hand, hydroelectricity seems like the holy grail of renewable energy, especially in places where pollution is a problem. As long as the river where the hydroelectric dams are located keeps flowing, there is an unlimited supply of clean energy. 

The benefits of hydroelectricity are best felt in Bangkok's massive shopping malls. Often referred to as the hottest metropolis on Earth, Thailand's crowded capital city is filled with retail emporiums. On one stretch of the main avenue, Sukhumvit Road, there are no fewer than six malls within three miles. People come to these places to shop, but they also come to spend the middle of the day in air-conditioned comfort while the tropical temperature hits triple digits outside. 

Because of this desire for artificial cool, some of these malls consume more energy than entire towns. The glitzy Siam Paragon (above), for example, eats up twice as much power as the Thai mountain hub of Mae Hong San. Whether or not you see these malls as overly decadent in a country that is still developing economically, there is no denying that having a renewable source of energy to power them is much better than relying on natural gas or some other sort of non-sustainable power source. 

A fisherman heads home along the Mekong River in Kampong Cham, Cambodia

A fisherman heads home along the Mekong River in  Kampong Cham, Cambodia. (Photo: Julia Maudlin/flickr)

The two faces of hydro power

The hydroelectric dams that give Bangkok's malls their juice are good for pollution, global warming and other "big picture" environmental issues. In underdeveloped countries like Laos, where the dams used by Thailand are located, the construction and operation is a boon for the local economy. 

But these dams bring up a major contradiction: they are at once good for the environment and responsible for destroying it. These structures change the flow of the river. This can impede the movement of wildlife, and disrupt the ecosystems that people and animals have relied on for centuries. 

The Mekong has mythical qualities. Long after traditional life disappeared in other parts of the region, people were still living a subsistence lifestyle here, fishing and farming the riverside flood plains. In some places there are no roads at all because people have always traveled everywhere by boat. The river still has prehistoric-size catfish — averaging several hundred pounds — and freshwater dolphins.

Men bathe in the Mekong River along the shores of Vietntiane, Laos

The Mekong River in Vientiane, Laos. In the upper right of the photo, men can be seen bathing in the river.  (Photo: Davidlohr Bueso/flickr)

River life is changing

The natural nutrients in the river have made this a prolific area for agriculture since the beginning of civilization. Blocking these natural sediments from flowing downstream could have a major impact on farming and fishing and, therefore, on the region's food supply. This would first affect the subsistence-level river folk, but it could eventually challenge the entire region's food security. 

Dams also cause human displacement. The structure of these electricity-makers means that a reservoir has to be create upstream. This often means that inhabited areas have to be flooded. This is the aspect of damming that creates the need for people, sometimes entire towns, to be relocated. Ironically, the people who will eventually be relocated from their bank-side homes often are the ones who are hired to build the dams. 

A man fishes in the Mekong River in Laos

A man fishes in the Mekong River in Laos. (Photo: Rob Young/flickr)

More dams are coming

A number of dam projects are in the works along the Lower Mekong. Dozens more are either planned or already under construction on the river's many tributaries. And this is only on the lower reaches of the river. China has already built seven dams in the Upper Mekong region, and over a dozen more are in various stages of development

Why so much interest in dams? It is a question of economics. Major dam projects bring in foreign direct investment and create jobs in the short term, so they are popular with both local people (even though some will eventually have to relocate) and with the government. Much of the investment can come from outside, but the income stream for the country will be continuous once the electricity starts flowing. Laos and Cambodia, where there are currently 11 Lower Mekong dams are under construction, will use only a small percentage of the power produced. Most of the electricity will be exported to Vietnam and Thailand, where there is a great demand.  

From the "quick money" and economic stimulation standpoint, there is no drawback to these large dam projects. Wind, solar or smaller-scale hydroelectric options do not offer as many economic incentives up front. It remains to be seen if cleaner, fossil-fuel-free air is worth the changes that will inevitably come to the Mekong's fisheries and agriculture industry.

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