(Feature image of rescue operations at Tapovan Vishnugad barrage following Feb. 7, 2021 deluge in Dhauliganga river, Chamoli. PTI Photo/Arun Sharma)
The tragic Chamoli flash flood episode has become latest and one of most vivid examples of how hydro power projects (HPP) are a recipe for disaster in geologically delicate and climatically sensitive regions of Himalaya.
Even 10 days after the deluge the Alaknanda Basin Rivers are following with muddier water. Death toll is mounting. The immense damages to infrastructure including roads, bridges, homes and hydro projects is still to be fully assessed.
The catastrophic event has offered authorities many valuable lessons: not to be blind to the preventable disasters the hydro projects are inviting frequently.
Initial findings have established that the reason behind the flash flood was detachment of snow and rocks. The fact that the hydro projects and other man made mistakes have led to most human casualties and financial losses is undisputable.
The deluge has hugely damaged two HPPs: the operating 13.2 MW Rishiganga at Raini village and under construction 520 MW Vishnugad Tapovan about 8 km downstream.
While the Rishiganga project is located in para glacial zone about 2000 meters above sea level, Tapovan Barrage FRL is 1803 m. Experts have been raising alarm bells including their structural safety since the beginning. But these concerns have been brushed under the carpet by the developers and government agencies.
Rishganga project developer has been blamed[i] for carrying out blasting, excessive mining and tree felling in ecologically fragile region. In violation of norms, the proponent has also dumped muck close to river making the area disaster prone during flash flood. The concerns of locals and premonitions of geologists were ignored, including by the judiciary.
The developers of Tapovan Vishnugad HPP have been overlooking the threats and risks. The project has faced heavy damages multiple times earlier due to flash floods, increasing the geological challenges, its financial cost and making its commissioning uncertain. All this is due to the poor geological appraisal of the project.
The Tapovan Vishnugad Project
Tapovan Vishnugad[ii] HPP is a run of the river project being built on Dhauliganga river in Chamoli district. This is second project of National Thermal Power Corporation (NTPC) after entering into the hydropower foray.
The feasibility study of the project was started[iii] on December 31, 2002. Project implementation agreement was signed on June 23, 2004. The foundation stone was laid on February 14, 2005. Construction work started in November 2006. It was scheduled to be commissioned in 2012–2013, with the first unit coming online in September 2012. The initial cost of project was estimated to be Rs. 2978.48 Crore.
The project required conversion[iv] of 144.59 hectare of land for permanent structures and ancillary sites. Of this 82.73 hectare was government land classified as forest and revenue land and 61.86 hectare was private land under cultivation by 630 owners in eight villages comprising Tapovan, Ravigram, Selang, Dhak, Paini, Paiya Chormi, Chamtoli, and Bhengul. The project also required resettlement of 57 households.
Salient features of Tapovan Vishnugad HPP
|Project Name||Tapovan Vishnugad Hydro-electric Power Plant|
|Coordinates||30°29′38.9″ N 079°37′39.1″ E|
|Capacity||520 Mw through four turbine (130X4)|
|Location||Dhauliganga river upstream of Tapovan in Alaknanda basin, Chamoli District|
|Catchment Area||3100 sq km out of this 1900 sq km is under snow cover.|
|Barrage||Height 22m, Length 50.5m with four bays of 12m and four gates of 12.30m X9.20m size.|
|Flood Design||Hydraulic, free board and diversion capacity of barrage is 4900, 6600, 250 cumecs respectively.|
|Head Regulator||Total length 46 m with four numbers of spans of 4 m size. It has four gates of 4m X 8.30m X 2.80m size with crest level at 1788m.|
|Sedimentation Tank||The size of sedimentation tank is 135m X 64m with four rows of hoppers of 15m X 16m size.|
|Head Race Tunnel||The standard horseshoe Head Race Tunnel is 11.646 km long with 4.80m diameter.|
|Surge tank||Surge tank is of restricted orifice type with 6.50m diameter in size.|
|Penstock||The main penstock size is of 3.55m diameter. It has four units of penstocks of 2.70m diameter.|
|Powerhouse||The powerhouse type is underground located 200m upstream of Animath gad and Alaknanda confluence.|
|Tail Race Tunnel||The horseshoe type tail race tunnel length is 500m with 5.30m diameter size.|
Information sourced from Geological and geotechnical investigations of Tapovan–Vishnugad HPP[v].
Construction of the barrage, Head Race Tunnel (HRT), Tail race tunnels (TRT) power house, and switchyard are major work for the project. The NTPC has awarded contracts to various companies for this. A description of which is given in table below.
|BHEL||Supply four 130 MW Pelton type turbines. Contractual scope included testing, commissioning and operation of the generators, switchgear and excitation system.|
|ABB||Supply of transformers.|
|L&T and Alpine Mayreder||HRT construction. The scope of the contract included the excavation of the tunnel and three Adits of total length 1.25km.|
|Rithwik projects||Barrage and desilting chamber construction works.|
|Patel Engineering||Underground powerhouse construction and related civil works contract. It also undertook the construction of surge shaft, pressure shaft, penstock, tail race tunnel, and switch yards.|
|J.M. Baxi and J.C. Motors||Transportation of the Tunnel Boring Machine (TBM).|
|SSNR Projects||Construction of barrage, river diversion/training works, and desilting basin works.|
|Commtel Networks||Sub-contracted by BHEL for providing a CCTV system for the power house and the barrage stations.|
|HCC||Due to delay in tunnel construction work, contract with L&T and Alpine Mayreder in 2014 was terminated. The work was awarded to Hindustan Construction Company (HCC) in March 2016.|
Details of Delays, Damages and Destructions
The project has been facing serious implementation issues since the beginning. Its barrage and coffer dam has been damaged repeatedly by flashfloods in 2011, 2012 and 2013. The TBM is stuck in tunnel since December 2009 and has not been recovered as of now. The construction work has so far adversely affected the river eco-system and local residents. The developer has also been unable to dispose the tunnel muck safely. For improper planning and negligence the project has suffered financial losses, structural damages and repeated delays in commissioning. A short detail of the issues is mentioned in table given below.
|Month/ Year||Delays, Damages and Destructions|
|Dec. 2009||The Aug. 2015 research paper by C.P. Nawani mentioned that the project TBM was stuck[vii] up at RD 3016m due to major rock fall on the shield near cutter head, in December, 2009. This led to sudden ingress of water (600-700 L/s) in HRT, damaging the pre-cast lining in the crown portion. The water ingress was from quartzite rock through some wide open joints, fractures or fault which were progressively widened due to groundwater movement and caused instability problems. The major problems associated with the heavy ingress of water were found to be difficult working conditions, damage to the structures, stability problems and environmental impact to the groundwater resources. The work was called off for more than 10 months in 2010.|
|Aug. 2011||The coffer dam of project was reportedly damaged during monsoon flash floods.|
|Aug. 2012||The Aug. 19, 2013 and November 2013 reports by The Daily Pioneer and Himalayan Desk mentioned that the coffer dam of the project was broken[viii] by flash floods in August 2012 during the monsoon. It also reported that the water was dangerously leaking[ix] in the tunnel for the past four years.|
|Oct. 2012||Hindi news report by Amar Ujala mentioned that the NTPC was involved in illegal mining[x] of riverbed minerals for the project despite some action by administration. It also stated that NTPC had diverted river channel near the project.|
|June 2013||SANDRP in October 2014 blog has quoted energylineindia.com stating that the diversion tunnel of the project which was completed in April 2013, was washed away[xi] during June 16, 2013 flash floods. The diversion dyke was also washed away and damages were observed in chormi adit approach road delaying the project for 12 months. The Power Technology report stated that the construction work of the project was severely affected[xii] by flash floods in June 2013. The July 2013 report by Down To Earth also mentioned[xiii] about this.|
|Jan. 2014||The Project Monitor report revealed that the June 2013 flash floods forced NTPC to postpone the commissioning[xiv] of the plant to June 2016. It also stated that even the revised deadline might be difficult to achieve considering the fact that HRT contractors L&T and Alpine Mayreder pulled out of the contract citing safety reasons. Further the Patel Engineering, contractor entrusted with power house works, was unable to perform any work since May, 2013 owing to cash flow problems and NTPC was considering bailing out the contractor by providing advance of Rs 18 crore.|
|June 2014||Following damages in June 2013, the BHEL refused[xv] to start work.|
|Jan. 2015||The Daily Pioneer report stated that in open violation of norms the Rithwik Projects Private limited was dumping muck[xvi] in Dhauliganga from Dhak muck dump and piling up the debris along the river. The report also mentioned of local villagers blaming the company causing damages to river bank vegetations while the authorities were looking the other way.|
|Aug. 2015||The Daily Pioneer report mentioned about seepage of water[xvii] causing delay in tunneling work and land subsidence problem due to tunneling. The CPI (ML) blog expressed concerns over repeated damages[xviii] to the project and adverse impacts on water sources due to seepages in tunnel work.|
|Dec. 2016||The Tunnel Talks report carried out some details on efforts[xix] being made to recover the TBM. In March 2016, NTPC awarded HCC the contract to complete the balance of works on the HRT with the 34-month contract based on an item rate basis. In November, HCC awarded a subcontract to Seli Overseas for recovery-and-completion challenge for the TBM-related works. “The previous contractor had bored just more than 6.3km of the tunnel, leaving a balance of work for the TBM of slightly more than 2.8km, Area Manager, Michele Sposetti”, for Seli Overseas told TunnelTalk. “The TBM is stuck at chainage 5,859m,” he said, “and the geology is complex with gneiss and potential for further weak zones and associated geothermal inflows.”” Referring to Geoconsult notes it states that the geological and construction difficulties along with instances of rock wedge movements and high volume water inflows were encountered primarily in 2009 and 2012.|
|July 2017||Piyush Goyal the then energy minister on July 20, 2017 made a detailed statement[xx] in Loksabha on status of ongoing HEPs across country and on page 12 serial number 35 mentioned that Tapovan Vishnugad project has been facing delays due to heavy water ingress in HRT and rock fall on TBM. As per this, the TBM had struck up thrice and flash flood in June, 2013 and August 2012 had damaged coffer dam. The termination of civil contracts for barrage and HRT work has delayed the project. The statement also revealed that originally estimated cost of the project had increased from Rs. 2978.48 crore to Rs. 3846.30 crore by Jan 2014. As per recent report, the project cost has gone upto 13,500 crore and it was scheduled for commissioning by 2023.|
|Dec. 2018||The Amar Ujala Hindi report stated that the project work was stopped[xxi] for few days on account of illegal crusher unit of NTPC in the river and not providing employment to locals.|
The affected villagers with their 20 demands including employment and rehabilitation were sitting on protest for last 20 days and dialogue with NTPC failed as per this Dec. 25, 2018 Amar Ujala report. The protesters had even threatened to stop barrage construction work at that time.
|Jan. 2019||The report by 43rd Standing Committee on Energy (2018-2019); 16th Lok Sabha (annexure VI, State-wise details of under construction HEPs above 25 MW having time overrun, page 98) mentioned that NTPC had failed to commission the project as scheduled time of March 2013 and the project had missed the second deadline of March 2016. The project had got third extension to complete the project by December 2020. The project had been delayed by 93 months[xxii]. The reasons for delays and issues included (1) Heavy water ingress due to bad geology in HRT and rock fall on TBM. (2) TBM struck up thrice. (3) Flash flood in June, 2013 and August 2012 damaging coffer dam. (4) Termination of civil contracts for Barrage and HRT. (5) Cash flow issues with civil contractors. (6) Excavation of HRT by TBM.|
|April 2019||Dainik Jagran Hindi report mentioned about TBM struck[xxiii] in the tunnel since 2012 due to some landslide underground. On separate note, it’s assumed that the cost of TBM is estimated about Rs. 200 crore and it was charging Rs. 2 crore per day for tunnel excavation.|
|Aug. 2019||Amar Ujala Hindi report stated that the TBM was repaired[xxiv] and tunneling work would start. However there is no official report available confirming this.|
|Jan. 2020||Hearing plea filed by Gram Pradhan and residents of Tapovan against muck mismanagement by the project developer, the National Green Tribunal (NGT) in 2019 directed the Uttarakhand Pollution Control Board (UPCB) to form an expert committee and submit a field report. The UPCB formed the panel in January 2020 and visited the muck dumping sites in March 2020. The report submitted to the NGT has found several lapses[xxv] in safe disposal of the muck by the project proponent. Overall there are five muck dumping sites of which three have reached full capacity and two remaining at Dhaak and near TBM adit are found nearing completion. The muck on all sites was found dumped improperly with potential to run off to the river during rains. The protection walls at Dhak and TBM were also found damaged.|
February 07, 2021 disaster
The deluge has exposed the NTPC’s poor disaster management. The disaster has not only damaged the permanent structures but also several of its ancillary facilities including the office.
Reports, satellite images show most of the barrage structure has been washed away. The long stretches of remaining area up and downstream the barrage have been buried several feet under the sludge and debris. The same have filled up and choked large part of the tunnels hampering the rescue work greatly.
The NTPC has reportedly suffered financial losses[xxvi] wroth Rs. 1500 crore. Despite constructing the project since 2006 and facing damages repeatedly, it has not installed any early warning system. The TBM issue proves that the company grossly under-appraised the geology of the region.
The Joshimath town not very far downstream from the project is sitting on a landslide prone zone.
Out of 204 missing people (it is not clear if there are proper records of all the people working at the project site), 139 (about 68%) were working in Tapovan Vishnugad project and 53 (about 26%) in Rishiganga project. So far the bodies of 64 have been recovered by February 18. This shows that of total missing persons, about 94% people were working for the two hydro power projects. Most of the workers were on weekly off due to Sunday otherwise the death toll could have been much higher.
Terming it criminal negligence on part of NTPC, MATU Jansangthan has demanded independent inquiry into the matter by experts under a retired Supreme Court or High Courts judge. The MATU blog[xxvii] has also mentioned that the gates of Tapovan Vishnugad barrage were closed during the deluge thus causing spillover of sludge which trapped many workers unaware. There is horrific video on social media showing about a dozen workers trapped[xxviii] on top of the barrage and being washed away.
Shockingly[xxix] as reveled by The Hindustan Times report, the NTPC officials were relying on communication from Rishiganga officials for flash floods. The report also stated that local alarm system at both projects failed as happens often with hydro projects. Despite Ravi Chopra committee report underlining dangerous lacuna in disaster preparedness in hydro projects after Kedarnath calamity, the project developers had done nothing worth mentioning in this regard in the eight years. Even the workers have alleged[xxx] lack of training, alarm systems and safety exits at project site and tunnels. Clearly, absence[xxxi] of advance or updated disaster systems has led to deaths of precious lives.
It is indeed one of the most remarkable incident[xxxiv] during Chamoli disaster in which Vipul Kairuni of Dhaak village in Tapovan, working at the now destroyed Tapovan Vishnugad project, got saved thanks to frantic calls by his mother Mangshri Devi as she and Vipul’s wife saw from their village home, situated at a height from the river, that a massive flood was approaching the dam site. It was due to repeated calls by Mangshri Devi that not only Vipul, but at least two dozen more people could run to safety of a ladder and save their lives. She did exactly what the disaster management department should have been doing.
In fact, speaking in the inaugural session of the NIDM-FICCI Training Program on “Resilient Infrastructure in Hilly Areas: Avalanche, GLOF & Debris Flow” on Feb 18 2021, the Director of WIHG, Dr Kalachand Sain said that there was sufficient time[xxxv] for NTPC to evacuate all the people at risk at the Tapovan Vishnugad hydropower project.
Questions are also being raised on inefficient post disaster cooperation by developers with rescue teams. For two days Ritwick Projects despite network connectivity could not provide tunnel outlay[xxxvi] to disaster management teams where 37 workers were trapped as reported in The New Indian Express. As per a rescue official, for first two days (till February 9) we were blind as they did not have a layout of the tunnels they were negotiating with.
Again on February 11, the rescue work at tunnel was stopped for two hours following a sudden rise of nearly 3 meters water level in Alaknanda river. At that time about 50 persons including district officials and reporters were in the middle of a press briefing and they had to run for their lives. Strangely, there was no timely information[xxxvii] from the official agencies except the phone calls of people from Raini village.
It is also alleged that the NTPC could not furnish confirmed information on which part of tunnel the workers were stuck and ways to approach them leading to frequent changes in rescue strategy and rendering evacuation operations futile[xxxviii] for first six days thus raising suspicion in district officials and enraging the affected people.
A fresh controversy[xxxix] has erupted on February 17 when MS Khati, Additional Chief Medical Officer Chamoli claiming the workers were alive in the tunnel till February 12-13 while Dr GS Rana, Chief Medical Officer refuting the claims saying that under the circumstances it was impossible for victims to survive beyond 30 minutes.
The flood has severely affected[xl] the river eco-system of Alaknanda, Dhauliganga, Rishiganga as long as 100 km stretch killing fish in large amount and experts feel rivers may take at least one year to restore the aquatic life to before deluge status reports The Times of India.
The Tapovan Vishnugad project has become classic example of hydro projects failing miserably on all fronts. It has clearly become a financial burden and repeatedly being damaged by flash floods. The cost has gone up by about five folds than initial estimates. Commissioning has been delayed by almost a decade. The project has become unviable. The project should in any case be scrapped considering it is in paraglacial influence zone.
Much of its structure has already been ruined, so it would be in larger interest of all stakeholders to dismantle the remaining parts.
Compiled by Bhim Singh Rawat (email@example.com)