News
Monday, April 05, 2010
Hunza landslide lake threatens to engulf valley* Swelling waters of natural dam rising at 30cm a day, just 30 metres from brim
* Analyst says as many as 45,000 people in danger from flood waves that could be as high as 40 metresDaily Times Monitor
LAHORE: A seven-mile lake formed by a massive landslide in the country’s northeast is threatening to burst its banks and sweep through a valley, wiping out villages and endangering 45,000 people who live downstream, the Independent reported on Sunday.
Although engineers are racing to build a channel at the top of the natural dam – formed by a landslide in early January that killed 19 people and blocked the Hunza River – they might have little time left. Their efforts will let the water drain from the lake gradually, but the water, which only a week ago was rising at a rate of 45 centimetres a day, is now going up daily by 30cm.
And the growth is likely to accelerate as glaciers and snowcaps in nearby mountains start to melt.
Swelling: The swelling waters of the huge lake are now just 30 metres from the top.
Professor David Petley, of the International Landslide Centre at Durham University, told the Independent that there was “substantive risk of an outburst” as the water level approached the top of the dam, with a “potential for a large flood wave to travel downstream as far as Tarbela Dam”, 50 kilometres northwest of Islamabad.
Warnings: “When the water reaches the top there are two scenarios. One, water goes into the channel that the army is cutting and there is no flood. It sounds like an attractive prospect but you have a huge body of water behind a landslide dam. Two, if the water goes, it would be caught by the Tarbela dam downstream – and the reservoir there is low because of the drought in Pakistan – but as many as 45,000 people are in danger of a flood wave,” he told the paper. “A wave could be 40 metres high, or even more, as it goes down the valley.”
The dammed river, from which the lake has formed, runs through Hunza, the former mountain kingdom renowned as the fabled Shangri-La, and feeds into Indus River on which the Tarbela dam lies.
More than 1,600 people have been displaced from the surrounding villages and the waters are encroaching on several more villages.
Locals watch helplessly as the water rises.
Shah Makeen, a fruit seller from Shiskat, a village a few kilometres east of the landslide, told the Independent that at the end of March, “when I visited the area, my home was slowly being engulfed by the massive lake”.
Focus Humanitarian Assistance, a charity affiliated with the Agha Khan Development Network, is setting up an early-warning system to alert villagers downstream in case the dam shows signs of collapse.
They have built a monitoring camp above the lake to check for cracks and have installed CCTV and night-lights to monitor seepage or any unusual activity in the dam.
Professor Petley said more needs to be done. In his report, he said “while constructing the spillway is undoubtedly an appropriate first step, a great deal more work is urgently required in terms of management of the hazard... The downstream communities are facing a risk that is not tolerable – immediate action is required at a national level to protect the population between Attabad and Tarbela Dam”.
But for people such as Afsar Jan from Shiskat, who is watching the waters submerge his home, the authorities have done too little too late. “They should have done more sooner,” he said. “Our future is being destroyed in front of our very eyes.”
Courtesy www.dailytimes.com.pk