Himalaya May Become Most Heavily Dammed Region of the World

Published on May 26th, 2009 | by

The Himalaya region of the world is undergoing rapid change from global warming.  For example, glaciers in the Tibetan Plateau are melting at a “worrisome speed,” according to Xinhua news agency.   Over the past 40 years, Tibetan glaciers have receded 196 square KM, or 1/4 the size of New York City.  Despite such loss of glaciers that feed important rivers in Asia; India, Pakistan, Nepal and Bhutan plan to build hundreds of mega-dams to power South Asia.

Image by marina & enriqueMega-dams planned for Himalayan rivers
Mega-dams planned for Himalayan rivers

In the next 20 years, over 150,000 megawatts (MW) of new hydropower projects are planned in four South Asia countries.  Three of these dams are the most expensive and largest dams in the world!  According to International Rivers, this is the “wrong choice for a warming world”.

A dam-building boom in the Himalayas in times of global warming is like investing billions of dollars in high-risk, non-performing assets. In the Himalayas, “melting glacier water will replenish rivers in the short run, but as the resource diminishes, drought will dominate the river reaches in the long term,” says Xin Yuanhong, a senior engineer with a Chinese team that is studying the glaciers of the Tibetan plateau.

Not only is the long term feasibility of such dams under question, but short term increasing flows from melting glaciers puts the safety of these projects in question.  The mega-dams have been designed based on historical river flow data. Climate change is causing increasing flows from melting ice causing some engineers to question the safety of the original dam designs.

Not only will climate change affect the proposed dams from melting glaciers, but increased storms could result in more flooding as well.  Another concern is glacial lake outburst floods (GLOFs).  International Rivers explains:

The sudden bursting of glacial lakes is another major concern for the safety of planned dams, and ultimately the rivers and peoples of the Himalayas… As glaciers in high-altitude regions such as the Himalayas melt, they can form large lakes behind temporary dams of ice and rock. When these moraine dams collapse, millions of cubic meters of water are released, resulting in massive flash floods. The Dig Tsho GLOF in Nepal in 1985 was one of the most devastating glacial lake bursts in recent history. The bursting of this glacial lake near Mount Everest caused a huge flood wave that travelled down the valley, killing five people and destroying one hydropower station, many acres of cultivated land and 14 bridges.

In January 2009, the government of Bhutan identified more than 2,600 glacial lakes in the country, of which 25 are considered to be at high risk of bursting, according to Yeshi Dorji of Bhutan’s Department of Geology and Mines. While Bhutan is aware of the risk of GLOFs and is improving its early warning system, the country, together with India, is still currently constructing one of the largest hydropower dams in the region, the 90-meter-high Tala project on the Wangchu River.

Over one billion people rely on the waters of the Himalaya for survival, and massive dam building will negatively affect this important source of water.  South Asia should look at other sources of renewable energy, as dams have been proven to be detrimental to ecosystems in America.  Damming Asia will not solve the world water crisis while meeting the energy needs of this growing region.

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