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. Last Updated: 07/27/2016

Tajik Lake Called Ticking Time Bomb

GENEVA -- A mountain lake held back by an unstable natural dam in the former Soviet republic of Tajikistan is a huge disaster waiting to happen, say scientists and relief agency officials.

Lake Sarez, high in the earthquake-prone Pamir Mountains, could flood parts of Tajikistan as well as parts of Afghanistan, Uzbekistan and Turkmenistan if an earthquake caused the dam to collapse.

That could send a wall of water into a 51,800-square-kilometer area populated by 5 million people, said Samuel Grigorian, a Moscow State University professor who has prepared a model to predict the flood impact of the dam's failure.

"The event could easily become the deadliest natural disaster in history,'' said a report by the UN Department of Humanitarian Affairs, which coordinates UN relief operations.

The threat has received little attention in Russian news media, and the experts concede they don't know when or how badly an earthquake might damage the dam.

But the specialists, who are urging governments to act to prevent a disaster, say they must tackle "worst-case scenarios.''

"The problem is major and time presses forward,'' said Yury Kazakov, a geological expert with the New York-based environmental consultancy KAM.

The 60-kilometer-long freshwater lake has been studied for years by Kazakov and other scientists and was the major topic at three international disaster-reduction conferences this year, including a UN-sponsored meeting in Geneva in October.

The experts envisage two scenarios from an earthquake: Either the unstable cliff above the lake could collapse into the lake and throw a huge wave of water over the top of the dam or the dam itself could break up.

"If a powerful earthquake occurs -- and it will definitely occur because quakes happen there all the time -- rocks will collapse and this mass [the cliff] will fall into the lake, pushing the water out,'' said Grigorian.

Earthquakes in the area are frequent and have reached a magnitude of 9, said Arkady Sheko, head of geology at the All-Russia Institute for Geology and Engineering Technologies.

After destroying the shaky top of the dam, the flood would wash away the remainder -- possibly emptying the whole lake, said Grigorian.

Although experts cannot predict exactly how many people would die in a flood, the wave would wipe out practically everyone living in the gorge below the lake, Grigorian claimed.

The nearest villages are 30 kilometers from Sarez, and a flood wave, moving at about five meters per second, would reach them in less than an hour then hit bigger towns, said Sheko.

Sheko, who claimed to be the first to alert the Soviet government to the problem in the 1960s, said it was unrealistic to strengthen the dam enough to resist a wave caused by the cliff or other massive rocks around the lake.

"There are rocks the size of five-story buildings, whole massifs,'' said Sheko.

Lowering the lake's water level could solve the problem, but that would cost millions of dollars, he said.

All equipment would have to be flown in because there is no land access, and a pipeline would be needed to remove the excess water.