Lok Sabha Question No. 68 (STARRED), answered on 2023-12-07
Subject: Floods in Sikkim
Ministry: JAL SHAKTI
Asked by: Pradyut Bordoloi

## GOVERNMENT OF INDIA MINISTRY OF JAL SHAKTI DEPARTMENT OF WATER RESOURCES, RIVER DEVELOPMENT & GANGA REJUVENATION

## LOK SABHA STARRED QUESTION NO. *68

ANSWERED ON 07.12.2023

## FLOODS IN SIKKIM

## *68  SHRI PRADYUT BORDOLOI

Will the Minister of JAL SHAKTI be pleased to state:

- (a)  whether  South  Lhonak  Lake  has  an  operational  early  warning  system,  especially  considering  its longstanding recognition of being at risk and if so, the

details thereof;

- (b) whether the preparedness and early measures in place were implemented during Sikkim glacial lake outburst floods and if so, the details thereof;
- (c) the details of the human casualties from the Sikkim floods and relief measures undertaken to support the affected families including the assistance/ funds given to the State; and
- (d)  the  details  of  the  assessment  made  and  monitoring  mechanisms  activated  by  the  Central  Water Commission in monthly monitoring of critical areas in North East such as South Lhonak Lake?

## ANSWER

## THE MINISTER OF JAL SHAKTI

(SHRI GAJENDRA SINGH SHEKHAWAT)

(a) to (d) : A statement is laid on the Table of the House.

## STATEMENT REFERRED TO IN REPLY TO PARTS (a) TO (d) OF STARRED QUESTION NO.  *68  TO  BE  ANSWERED  ON  07.12.2023  IN  LOK  SABHA  REGARDING  'FLOODS  IN SIKKIM'

(a) A  water  level  sensor  to  monitor  the  changes  in  the  water  level  of  the  lake  was  installed  at  the South Lhonak lake in the year 2016. The water level sensor was developed by C-DAC under Ministry of Electronics & Information Technology as a pilot project. However, due to inclement weather conditions prevailing at those high altitudes the system was damaged and collapsed after 6 months of installation. At present, there is no operational early warning system installed at South Lhonak Lake.

Recently, National Disaster Management Authority has taken up the pilot project for development and installation of Early Warning System for two Glacial lakes namely, South Lhonak Lake & Shako Cho Lake in Sikkim with technical support of Swiss Development Corporation and logistics support from Government of Sikkim.

(b) As informed by the Sikkim Urja Limited (owner of Teesta-III dam, which was washed out during the flash flood of 3 rd October 2023), emergency response system was activated by the project authorities and  the  warning  to  the  downstream  population  was  issued  by  way  of  sirens.  Chungthang  town  was informed about the possibility of flash flood. About 250 people from the project colonies at dam site were evacuated and shifted to higher level.  Downstream projects were also informed over telephone. National Disaster Response Force (NDRF) deployed 06 teams in Sikkim and 05 teams in West Bengal to  tackle  the  floods  in  the  affected  areas.  NDRF  teams  remained  deployed  there  w.e.f.  04.10.2023  to 01.11.2023.

(c) As  informed by the State Government, 46 human casualties including 15 army personnel have been  reported  during  the   flash  flood  in  the  Teesta  River  basin  in  Sikkim.   Relief  materials  were distributed by the concerned agencies to the affected population as per the norms.

(d) 477 Glacial Lakes/Water Bodies (GL/WBs) having size above 50 Hectare (Ha) were monitored on  monthly  basis  from  2011-2021  jointly  by  National  Remote  Sensing  Centre  (NRSC)  and  Central Water Commission (CWC) using remote sensing data. From 2022 onwards, 902 GL/WBs  are being monitored using remote sensing data. These consists of 544 Glacial Lakes above 10 Ha and 358 Water Bodies above 50 Ha. The monitoring is carried out in respect of changes in their water spread during monsoon season from June to October, every year.

Out of 544 Glacial Lakes, 100 Glacial Lakes are in India. Out of that, 41 are in Sikkim including South Lhonak Lake and 10 are in Arunachal Pradesh.

Water Spread area of South Lhonak Lake varied from 100 Ha to 160 Ha during monthly monitoring period i.e. June - October during 2011-2023. Maximum area was 169 Ha & 171 Ha in Sept 2022 & Sept 2023 respectively.

Monthly monitoring reports are shared through email with all the concerned stakeholders. The reports are also published on the CWC website.