(Feature image: Arial view of Bhimtal Lake and dam. Source:- Postoast.com)
All is not well with Bhimtal dam in Nainital district, Uttarakhand. On March 8, 2021 morning, the fillers from its protection wall wobbled out. It sparked panic among local residents living near the largest lake of Kumaon region. For past couple of years they have been concerned about the structural safety of the aging dam. The 138 years old dam has already been in news for vertical cracks and recurring seepages.
March 8 2021 incident
The hill town faced high velocity winds creating turbulent waves in the lake waters on March 8 night. The high tides put the pressure on one side of protection wall and in the morning a small part of it was seen falling apart[i] near Bhimeshwar temple in Danth area. In fact, the protection was created to support the main wall of the dam which has cracks for a long time. While the residents living in close proximity became restless, the Irrigation Department has not found it necessary to act so far.
Given past cracks and seepages the locals feared a dam break threat round the corner and alleged the Irrigation Department did not show the urgency. They also said that the dam need an urgent repair but authority is limiting itself to some yearly whitewashing. Reacting to the matter, Ram Singh Kaida, the local MLA expressed concerns[ii] over dam safety and asked the Department to fix the damaged wall, which the latter promised to undertake soon.
Bhimtal[iii] is a gravity masonry dam located about 22 km downstream Nainital lake. It was created by damming the outlet of Bhimtal lake in 1883 during British time. It is also known as Victoria dam. The dam is certainly a Large Dam, considering its height, but it is not included in the National Register of Large Dams of CWC: http://cwc.gov.in/sites/default/files/nrld06042019.pdf
Salient features of the Bhimtal Dam
|Location||Bhimtal town, Nainital|
|Geo Coordinates||29°20′35″N 79°33′33″E|
|Elevation from MSL||1375 m|
|Catchment Area||17.12 sq km|
|Surface Area||47.8 ha|
|Height||16.16 m from foundation|
|Maximum Depth||18 m|
|Full Reservoir Level||13.87 m|
|Minimum Draw Down Level||5.18 m|
|Gross Storage Capacity||4.61 MCM|
|Live Storage Capacity||3.54 MCM|
|Dead Storage Capacity||1.07 MCM|
|Estimated Surface Inflow||1.756 MCM|
|Flood Capacity||45 Cumec|
|Weir Width at Bottom||11 m|
|Weir Width at Top||3 m|
|Outlet Wall Type||Curtain|
|Type of Spillway||Chute|
|Type of Spillway Gates||Log|
|Source of Water||Bhima rivulets & subsurface flow|
|Sub-basin/ Basin||Gola River/ Ganga|
After making Nainital as summer capital, the British administration planned to develop Bhimtal lake[iv] area as hill station. At that time, Francis Henry, the then Commissioner of Kumaon found damming the lake to be useful for supply of irrigation water to downstream areas including Haldwani.
The lake is formed on Bhim rivulet a perennial forest stream in the area. The subsurface flow[v] constituting around 35 to 80% of the total surface runoff in monsoon and non-monsoon months, also feed the lake. Geologists believed that the lake formation is result of several faults which occurred due to shifting of the earth’s crust blocking the surface flows.
The river, lake and town are named[vi] after Bhim a legendary character of Mahabharat who happened to visit the area during Pandavs exile. There is an ancient Bhimeshwar temple close to dam outlet built by Raja Baj Bahadur Chand of Kumaon Kingdom during the 17th century.
Kainchuli Devi is another famous temple near the lake devoted to local goddess locally believed as the protector of boatmen[vii] at lake. Her shrine marks the site of the original temple which submerged when the dam was built. The pedestrian track along the lake bank has been part of historical silk route.
The lake is located at an elevation of 1375 m in seismic zone IV. Presently the Bhimtal town has become famous tourist spot and lake is used for boating, fishing, water sports, aqua farming purposes and other recreational activities in addition to meet irrigation and drinking water supply for Bhimtal and Haldwani town. The discharges from the dam supplements Bhahar canal system on Gola river.
An artificial island has also been created inside lake some 85 meters away from outlet which supports an aquarium and has become centre of tourist attraction. A peripheral road along the bank of triangular shaped lake enables visitors behold its panoramic beauty and rich aquaculture and riparian biota.
Over the years, the overcrowding and growing development pressures[viii] have led to degradation[ix] of its catchment area, increasing both siltation and sewage pollution in the lake cumulatively impacting its water quality[x] and quantity. The area has become more prone to landslide following slope cutting and tree felling to facilitate building construction.
A study has found more than 22% shrinkage[xi] in aerial extent of Bhimtal lake and significant drop in lake water quality. There is significant decline in water inflow also as the perennial feeder stream going seasonal gradually. It even dried up[xii] for the first time in recorded history in 2013. The lake requires regular dredging and talks of sewage treatment plant are going on for years to address sewage pollution. However the repeated warnings of dam collapse have apparently been ignored so far.
Growing concerns of dam safety
The biggest reason for frequent complaints and concerns by local residents behind possibility of serious damage to dam structure is that the dam has become 138 years old.
In Dec 2014 article dammed dam of Bhimtal[xiii] in Governance Now, Rajshekhar Pant has underlined the imminent threats to the safety of the dam. It also mentions about two unsuccessful attempts made in 1850s and 1870s to create earthen dams on Bhimtal lake before the construction of the present dam. The structures were washed away by severe flood of Aug 1882. The design of the present structure has warned against air or water tension along the horizontal section of the reservoir.
When the Britishers left, they had advised the Indian engineers to take utmost care of dam structure and conduct repair work regularly. However, since then the dam has not gone under any major repairs. Except some cement plastering work to fill the cracks or wall repairing when they crumble as band aid solution. To make it look presentable to tourists and VIPs, the whitewashing and painting work is the only task the dam managers ritually conduct.
The worries against looming risks have only grown louder and renewed after June 2013 Kedarnath disaster. Possibly in 2012 or 2013 monsoon, the dam was filled upto the level of 44 feet (13.41 m) in decades which sounded alarm bell and the downstream people were evacuated in night hours before emptying the water back to safe level.
In nineties, there was a proposal to increase the dam height as a solution to siltation problem eating into storage capacity which was dropped following categorical rejection by Irrigation Design Organization (IDO), Roorkee cautioning against any tinkering with the dam may be fatal.
This para from the Governance Now article describes the causal and negligent approach prevailing in administration regarding dam safety: “The International Commission on Large Dams (ICOLD) recommends that estimation of the bottom cracks and the consequent weakening of the interior of the dam should be done following core drilling. Showing a deep concern over the existing state of the dam the report speaks of taking up restoration work without further delay. This report, understood to have been forwarded to the office of the Principal Secretary on June 30, 1995 “must have been gathering dust in some plush office at the state secretariat in Dehradun,” says an insider from the administration.”
The article has also reported that one of the mechanical sluices initially installed in the dam is lying defunct for over a decade about which no one seems bothered.
The evolving worries and threats
In June 2012 Hindi report[xiv] local reporter Prayag Pandey found that the large part of lake had dried up. He also mentioned of increasing concrete construction in the catchment of Bhimtal leading to more siltation in lake area.
As per the report the dam is filled upto 44 feet by the Irrigation Department in monsoon. From May to June half months about 50 cumecs water is released to meet irrigational supply in Bhabar area but the level has to be maintained at 22 feet.
Referring to Chief Engineer, the reporter mentioned silt accumulation in some 12000 sqm area in Mallitaal side of the lake and a proposal of Rs. 7.84 lakh submitted to Union Water Ministry for dredging and other protection work.
With increase in water level, the dam wall towards Bhimeshwar temple suffered seepages states the a, January 2015 report. It also finds bushes and small plant growing over the dam wall. It says, the main scab gate of the dam is out of work since 1980[xv] and Irrigation Department had place gravel filled sacks to plug leakages as a temporary measure.
The report finds leakages at other places of dam wall, stating if it collapses, it would wash away dozens homes of municipality colony built right downstream the dam and flooding the Ghatigad, Bilaspur, Tok Naul of Naukuchiatal and Sahkhola, Harinagar, Dhungshil Malla, Berijala, Khairola Pant, Khairola Pandey area of Amritpur, Amiya in Ranibagh further downstream.
A Nov 2017, report informs about increase in leaking water amount and places[xviii]. Similar incident had taken place five years ago in winter which was then repaired by the Irrigation Department. The report had also quoted Irrigation Department engineer saying that the wall was built using local lime stone and there was no threat to dam structure.
A Feb 2018 news reports of threats[xix] from cracks and seepages in dam wall and alleges administration to be non-serious about the issue. Another report of same month mentions about the inspection visit[xx] of Roorkee scientists team.
Dr. Sudhir Kumar, senior expert, National Institute of Hydrology, (NIH) Roorkee found no immediate threat[xxi] to the dam after the visit with his team. He said the bushes, plants outgrowing on dam wall need to be cleared and cracks should be filled.
In Aug 2018, a portion of supporting wall fell[xxii] into the lake creating threat to adjoining road. In the same month, protection wall of police station got damaged[xxiii] after heavy rainfall blocking the traffic.
Similarly, a part of road[xxiv] near Danth area slipped into the lake after rains in Sept 2019. As per a Nov 2019 report, local administration had approved a budget[xxv] of Rs. 9.98 lakh for repair of damaged lake walls. This Nov 2019 video report anticipates[xxvi] the destruction in the event of dam failure.
The state government was considering formation of a dam safety review panel[xxvii] comprising of experts from NIH and other departments discloses a Jan. 2020 Hindi report. The information was given by Satpal Maharaj, Irrigation Minister during question hour in special session of state assembly. He reportedly accepted that the Bhimtal dam was suffering from water leakage but denied it to be a threat to local people.
Another report covering the assembly session mentions about NIH informing government that it had contacted the Bhabha Atomic Research Centre (BARC) to study[xxviii] the cause of cracks in Bhimtal dam. During the discussion on the issue, Ram Singh Kaida the local MLA said that there has been no safety assessment of the dam in past and given the increasing leakages it should be rebuilt.
The Pioneer report reads “In its response the NIH has mentioned that the seepage cannot be marked by the normal isotope method so BARC help for use of gold isotope technology[xxix] to identify the seepage points is being taken,’’ Maharaj said.
As per the Irrigation Minister, the IDO, Roorkee has been given the task to analysis the safety of dam gates and further decision on the issue would be taken after the reports of NIH, BARC is received. The MLA also asked inclusion of local representatives in NIH, BARC inspection team to allay the fears of locals.
Further, Karan Mahara, Ranikhet MLA raised the issue of several British era dams, bridges reaching expiry date and posing a threat to public safety. He demanded an in-depth technical inspection of these old structures to work out appropriate steps.
In the same month, another report finds fresh seepages[xxxi] in Bhimeshwar temple area of the dam. As per the report the Irrigation Department was waiting for NIH response to its letter sent after the inspection visit by the NIH team.
A July 2020 report quoted Savin Bansal, district magistrate, Nainital submitting[xxxii] state government a Detail Project Report (DPR) for repair of the Bhimtal dam. The lake rejuvenation issue is struck[xxxiii] between Lake Development Authority (LDA) and Irrigation Department, shares another report.
The protection wall of parking lot crumbled down[xxxiv] into lake as per a Oct 2020 report. A Nov 2020 report mentions gradual sinking[xxxv] of Victoria park staircase along discharge channel of Bhimtal dam. The Irrigation Department is quoted saying a visit by BARC is awaited.
A Dec 2020 report informs that the dam safety matter reaching Prime Minister Office[xxxvi] (PMO). Manoj Bhatt, President BJP Mandal had written a letter to Prime Minister seeking PMO intervention, the report reveals. Following this, Mukul Dixit, Section Officer, PMO has reportedly instructed the Chief Secretary to take the action to resolve the matter.
The report also mentions that BARC team visit was delayed due to Covid 19 pandemic. It further shares a Rs 14 crore proposal for repairing and desilting of dam seeing, sent earlier by Irrigation Department seeing no action so far. Congress workers planned to stage protests[xxxvii] in Vikas Bhawan demanding repair of the dam and suspension of LDA, same month.
The Feb 2021 video reports[xxxviii] emphasize why the Bhimtal dam safety issues require urgent attention to prevent a disaster[xxxix]. Amid this the water leakage problem from dam wall has only increased and the cracks going wider[xl] finds a Feb 16, 2021 report.
Summary There is no doubt the dams have finite life and Bhimtal dam is one of the oldest we have. It is clear from all the media reports including about discussion in the Legislative assembly that there is no authentic report in public domain about the safety assessment of Bhimtal dam and steps that need to be taken to resolve the concerns in a time bound manner. That is the underlying theme of the dam management across India. With Central Water Commission at the helm and not changing its governance structure, there is little hope for change in this situation in immediate future.
Bhim Singh Rawat (firstname.lastname@example.org)
NOTE: We are thankful to an alert citizen of Uttarakhand, Lokesh Negi, for alerting us about the safety issues related to this dam. A resident of Almora, he passes by this dam every time he travels between Almora and Haldwani. When he saw the leakage from the dam during one of his recent trips, he made some enquiries locally and shared the news reports. Thanks a lot, Lokesh ji.