20 February 2012
Attabad landslide – reports indicate that the barrier will be blasted next week (updated)
Posted by Dave Petley
NB see update at the end of the post
The Express Tribune in Pakistan is reporting that the Attabad landslide (see summary post and Authorstream presentation), which formed two years ago and has caused huge disruption in Gilgit-Baltistan, will be blasted net week:
The spillways need to be blasted which in turn result in flashfloods due to the sudden release of water. The authorities, in an effort to minimise losses for the population living in low-lying areas, have sought time to make adequate preparations.
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.
“We have been informed by the home department about a change in date, with instructions to complete the preparations by the revised date,” Deputy Commissioner of Hunza Nagar, Burhan Afindi said.
Explosives will be used to blast the boulders currently obstructing the outflow of water though a spillway dug in 2010.
The article describes the measures that need to be taken downstream to protect the population against a potential flood:
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.
“Assistant Director, Youth, Wajid Ali has been assigned the task of assisting rehabilitation work if something untoward happens,” said Safdar Ali, an official in the PRCS. He added that the team has been trained and equipped to deal with any emergency.
I will provide updates as they become available. It is going to be very important to protect the downstream populations, and I hope that efforts are made to record the ways in which the dam behaves and the flood develops – we can learn a great deal about the ways that landslide dams breach from this event.
Update (22nd Feb): according to a comment below, this is the removal of a coffer (i.e. temporary) dam. This explanation differs from that in the article, which suggests that it is the boulders that are being blasted.
the said blasting is of a coffer dam which was constructed in last season. There is no likely hood of a flash flood its just precautions due to a chance of soil errosion. the dam constituent material is highly hydrophobic n turns into a impurvious mass on absorbtion. the silt content however makes it succeptable to washing, hence the precautions are necessary.
News being updated on Pamir Times site http://pamirtimes.net/2012/02/27/high-alert-in-hunza-nagar-gilgit-astore-and-diamer-as-spillway-blast-hour-nears/
[…] Pamir Times is reporting that the coffer dam at the Attabad spillway, shown in the above image from the Pamir Times, has been blasted today, allowing water to flow […]