Mega-dams have severe impact on the ecosystems; disrupts fisheries and reduces biodiversity
New Delhi: If all the large dams proposed by China on rivers within Tibet begin operations, the Brahmaputra river will never be the same again, warns a Canadian environmentalist who has done extensive research on the subject.
“Currently, Chinese engineers are constructing a five-dam cascade on the mid-reaches of the Tsangpo (Brahmaputra). Zhangmu Dam, with a capacity of 540 MW, has already started operation. The dam lies 86 miles southeast of Lhasa. Construction is under way on the other dams in this cascade,” says Michael Buckley.
“China claims these dams will have no impact downstream, but the fact is that these dams are just the start of things, with bigger and bigger dams on the drawing-board, such as 800-MW Zhongyu Dam on a Yarlung Tsangpo tributary. Within Tibet, at least 20 large dams are planned for the Tsangpo (Brahmaputra) and its tributaries. If all go into operation, the river will never be the same again,” he told PTI.
Buckley has also written a book “Meltdown in Tibet: China’s Reckless Destruction of Ecosystems from the Highlands of Tibet to the Deltas of Asia” in which he tries to focus on the darker side of China’s emergence as a global super power.
The book, published by Palgrave Macmillan, has a preface by the Dalai Lama in which the Tibetan spiritual leader says that “Meltdown in Tibet” should be “part of a wake-up call to the international community and China to seriously assess ecological and environmental conditions on the Tibetan plateau and take remedial measures”.
On the ecological impact on Assam and Arunachal Pradesh that may be posed due to the construction of big dams on the Brahmaputra and other rivers by China, Buckley says the fragile ecosystem is at risk.
The Great Bend (in Tibet) of the Brahmaputra from where the river begins its course towards India holds the greatest hydropower potential in the world, says Buckley, who has travelled extensively throughout Southeast Asia, and the Himalayan and Karakoram ranges and has made a documentary on major environmental issues in Tibet.
“A huge dam at the Great Bend would devastate the river’s fragile ecosystem – destroying the magnificent biodiversity of the Assam and Himachal Pradesh region. This is much more than a question of water coursing into India: a huge dam would withhold the river’s sediment from the fertile floodplains of Assam and Arunachal Pradesh. “A huge volume of nutrient-rich sediment (silt) flows down the Brahmaputra from Tibet. Dams block silt, thus affecting the food security of the nations downstream, which need silt for productive agriculture and to bolster the Ganges-Brahmaputra Delta against rising sea-levels. Tributaries swell the Brahmaputra from the Indian side, but the greatest sediment load comes in from Tibet,” he says.
Buckley suggests a moratorium on mega-dam building in Tibet – and across the entire Himalayan range – and including India’s own mega-dam-building plans.
“Mega-dams mean mega problems. Mega-dams have severe impact on the ecosystems that these rivers support, disrupting fisheries and reducing biodiversity. Water quality may be severely degraded in stagnant reservoirs,and whole communities must be relocated for areas flooded by dam reservoirs,” he asserts.
Buckley also suggests that India needs to stand up to this travesty. “India needs to negotiate water-sharing rights with China (as India has done with Pakistan and with Bangladesh).” Of the major consequences of rapid melting of Tibet’s glaciers, he says initially, the impact will be increased flow in the rivers – meaning flooding. “Then eventually that will be followed by drastically reduced flow (as the glaciers disappear) and then no flow at all. Monsoon rains cannot maintain the water levels in these rivers – they are dependent on glacier-fed water for the most part,” he says. (PTI)