Landslide dam threat in Zanskar Valley to continue for more weeks: Update 2

In the most significant event so far on the issue of landslide blockage of Phutkal River in Zanskar Valley in Kargil District in Kashmir, the National Crisis Management Committee[1] (NCMC) chaired by the Union Cabinet Secretary Shri Ajit Seth met[2] on Feb 20, 2015 and approved the Action Plan whose implementation will begin within next 15 days and is to be completed by end of March. This decision is based on assumption that the snowmelt will cause landslide dam threatening situation only in April.

Tsarap Landslide location and floodpath: Map by SANDRP based on Kargil District Map from NATMO

Tsarap Landslide location and floodpath: Map by SANDRP based on Kargil District Map from NATMO

In the meeting[3], the report submitted by the expert team of the NDMA that conducted survey of the site suggested two options: A. controlled blasting using explosives to breach the landslide and make a channel for flow of water B. Use of air force laser guided bombs for breaching the blockage. The meeting chose plan A in view of some concerns raised by the Indian Air Force regarding plan B.

The Action Plan As part of this plan to be coordinated by National Disaster Management Authority (NDMA), following steps will be required to be implemented:

  • A temporary helipad and a control room would be set up near the landslide, equiped with satellite phones
  • Snow clearance of over 40 km of road from Padum to Purne, treking for about 43 km from Purne to the site of landslide
  • Installation of flow monitoring equipment by Union Water Resources Ministry
  • Satellite monitoring of the landslide is being done and data is being collected on daily/ hourly basis.
  • Action Plan will involve integrated efforts from the State and Central Government agencies including Central Water Commission, Survey of India, Central Institute of Mining and Fuel Research, Snow and Avalanche Study Establishment, National Remote Sensing Centre, NHPC, Survey of India, BRO, Army and Air Force.
  • A rehabilitation plan to ensure safety of life and property of the inhabitants.
adakh Map from Reachladakh

adakh Map from Reachladakh

NDMA website Meanwhile, NDMA website[4] now provides (latest update of Feb 19, when possibly for the first time the site provided some information more than a month after it was alerted) an update on the landslide situation. It reveals that the visit of NDMA to the site happened only after an earlier NCMC meeting, possibly on Feb 4, 2015. It says: “On the basis of Flood Mapping prepared by CWC, State Admin has identified likely to be affected personnel/ hamlets and prepared a Rehabilitation Plan.  Advisories have been issued to all locals residing downstream and Water Monitoring Stations installed with communication facilities at identified sites.” The flood mapping or monitoring station data is not available in public domain!

Feb 9 meeting at Leh A detailed report of the first meeting held in Leh with the visiting NDMA team regarding this crisis on Feb 9, 2014 now available.[5] The meeting report provides a number of interesting new facts, some of which are listed below.

  • Kargil DC stated that they have placed an early warning system near the site which is 30 km downstream from the landslide site, but he considers this warning system too far from the landslide area. (It is not clear what this warning system comprises of.)
  • Kargil DC expressed concern about possibility of minor earthquake and cloud burst in the region that could lead to bursting of landslide dam.
  • CWC director V D Roy confirmed that according to the satellite reports there has been little on and off seepage in the landslide dam. He also stated that the satellite report has shown that the width of the landslide has increased from 90m to 110m. He said that the potential risk of its breach resulting in flash flood in this type of landslide dam can happen in three ways: one because of hydrostatic pressure acting horizontally pushing the mass to slide alongside. But this is ruled out keeping in mind the size of the mass and the volume of the landslide. Second is overtopping, means more pressure on the top creating a bend and then the water toppling the dam, this is also ruled out. ruled out. The third is that complete filling of the water in the dam will result in overflow of the dam and then a gradual erosion of the top surface creating a breach. It is assumed that the third case is going to take place in current case, if left to itself. (This is what happened in 1894 when landslide dam blocked Birahi Ganga in Uttarakhand, a year after the landslide in 1893.)
  • According to their calculations and the information given by NHPC the time that will take the flood to reach Nimmo, Bazgo Hydropower project that is in the range of 200 km from the landslide area will be around 10hrs. The nearest habitation that is Phuktal it will take the flood to reach about half an hour and to Padum 2 hr 30 mins to 3 hrs. This will help them install early warning system that will help them formalize the Emergency Action plan (EAP).
  • He also stated that keeping in consideration the current given information and according to their analysis the water level will rise to a height of maximum 15 m and recedes till 1 to 3m when reaches Indus river.
  • One of the options for mitigating measures is installation of an automatic monitoring system at Phuktal engaging some manual observation of the landslide site round the clock along with good communication system. This is since installation of early warning system at the dam site is not possible.
  • R D Patni, NHPC Chief Engineer said that Natural dam formations like in Zanskar will not get breached easily. He emphasized that the soil of the landslide is most probably in a permafrost condition which means, the temperature of the soil is in sub-zero condition where the water in the soil freezes and the soil becomes very hard. Even the possibilities of blasting and removing of the soil through excavator machine are not possible now. The danger of piping action (where the water gets in the soil slowly and the fine clay particle is removed, then because of the hydrostatic pressure it results into abrupt burst of water like a pipe) have to be prevented.
  • Skalzang Wangyal stated that if they are not able to stop the deluge then according to the study by the experts in the the low lying villages till Hanamur 80% of the habitation will be wiped off.

Earlier media reported[6] on Feb 19, 2015 an assurance by the NDMA secretary R K Jain that the operation to drain out the water pounded in the artificial lake will be commenced within a week’s time and all steps required will be taken to safeguard the lives and properties of the people”.

The tourism industry is worried that the impact of the landslide dam may extend into the summer adventure tourism[7]: “For the rafting community, Zanskar and Indus are great rivers to raft and Kayak on. The Tsarap Chu is a classic grade V Kayaking section and draws Kayakers to Ladakh from all over the World. The Zanskar river and gorge section is famously know as the “Grand Canyon of Asia”. Flooding of the river or any kind of sudden increase in water levels will definitely change its features and will majorly affect Rafting/Kayaking operations this Summer.”

In Conclusion It needs to be noted that the estimates and action plan are based on one on ground survey of a couple of hours and rest either aerial survey or satellite survey. This could be a limiting factor. Secondly we hope the experts have estimated the size of the reservoir and its strength and the reservoir does not overflow before the operation is successful and also that the temperature does not work suddenly, leading to melting of upstream glaciers before the dam is breached by the operation. There are lots of ifs s of now before the safe demolition of the landslide dam. In the meantime, we hope the authorities will be more forthcoming in sharing information with the people. They are not so far.

SANDRP (ht.sandrp@gmail.come)

Earlier Articles on this issue:

  1. https://sandrp.wordpress.com/2015/02/01/landslide-dam-blocks-zanskar-river-tributary-threatens-valley/, Feb 1, 2015
  2. https://sandrp.wordpress.com/2015/02/13/landslide-dam-blocks-phutkal-river-threatens-zanskar-valley-update/, Feb 13, 2015

END NOTES:

[1] http://www.ndmindia.nic.in/management/ncmc.html Union Home Secretary, Union Defence Secretary,NDMA head and invited experts attended the meeting. Chief Secretary and number of other officials of Jammu and Kashmir participated in the meeting through video conferencing.

[2] http://www.business-standard.com/article/government-press-release/ncmc-reviews-situation-of-blockage-on-phuktal-river-in-j-k-115022000702_1.html

[3] http://www.dailyexcelsior.com/action-plan-to-resolve-zanskar-river-crisis-to-begin-within-next-15-days/

[4] http://www.ndma.gov.in/en/news/958-blockage-of-river-phuktal-due-to-landslide-in-zanskar-sub-division.html

[5] http://www.reachladakh.com/ndma-held-meeting-regarding-phuktal-river-blockage/2702.html

[6] http://www.dailyexcelsior.com/karbalaie-seeks-azads-help-to-ease-zanskar-river-disaster/

[7] http://blog.whitemagicadventure.com/2015/02/10/disaster-unfolds-in-zanskar-valley-and-disrupts-chadar-trek/

One Comment on “Landslide dam threat in Zanskar Valley to continue for more weeks: Update 2

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: