2012-02-20

Pakistan Tribune: Hunza landslide dam to be blasted on Feb. 27th

Maybe you were following the flood risk created 2 years ago by the Hunza Valley landslide in January 2010. There were fears that once the lake overflowed it would trigger a massive outburst flood (you can have a look at my previous post, focused on this phenomenon). More than 25,000 people in Gojal were stuck after the massive landslide formed a natural dam in the Hunza River, creating a lake that consumed upstream villages as it expanded. The landslide also blocked the Karakoram Highway, a vital trade link connecting the region to China.

Now there are news about that. According to the Tribune of Pakistan:
The spillways need to be blasted (...)The district administration of Hunza Nagar made an announcement last week to blast the spillway on February 18, but put off the task till the 27th of this month.(...)Explosives will be used to blast the boulders currently obstructing the outflow of water though a spillway dug in 2010. Several unsuccessful attempts have been made in the past using controlled blasting to widen the spillway.An official said that traffic on the Gilgit-Hunza portion of the Karakoram Highway would be stopped on that day. Authorities also warned residents settled downstream to avoid venturing to the riverside. Pakistan Red Crescent society (PRCS) has deputed a team of volunteers to assist the administration in case of an emergency.
Let's hope everything is done safely and that the blast serves to get knowledge on how do outburst floods develop.


[Via The Landslide Blog]


Update 2012-03-01: Level went down by 7m after works to enlarge the spillway and the reopening by blast last monday. Good news for people living downstream: pamirtimes.net
This has been probably helped by the erosion produced by the peak discharge reached, about 50,000 cusecs (1400 m3/s).

Update 2012-05-15: Another blast of the gravel dam: Pamir Times.