Dams

Krishnagiri Dam Breach Is Wake Call For Dam Safety In Tamil Nadu And Elsewhere

On the evening of November 29, 2017, a shutter of Krishnagiri Reservoir Project[I] (KRP) dam in Krishnagiri district, Tamil Nadu has breached sounding flash flood alarm in downstream areas. The Collector C. Kathiravan has also put five districts of Krishnagiri, Tiruvannamalai, Dharmapuri, Vellore, and Villupuram on high alert following the sudden breach. The disaster management and rescue department have been called in to assess the situation. Leading a high level expert team Murugu Subramaniam Chief Engineer (CE) Public Works Department (PWD) responsible for operation and maintenance of the dam has also inspected the site which was followed by M Thambidurai. Deputy Speaker of the Lok Sabha.

Krishnagiri KRP Dam First Door Damage Viral Video

Interestingly KRP dam project is listed in the Central Water Commission’s national registry of large dams. It is also covered under Dam Rehabilitation and Improvement Project (DRIP) and there was an Emergency Action Plan (EAP) workshop at the dam site only in 2016. Surprisingly, the incident has occurred just a year after all the 8 shutters were repaired at a cost of ₹1.10 crore reports The Hindu.[II]

The flash flood would impact the downstream villagers particularly riverbed farmers. As the dam was storing water for rabi crops, the breach is also bound to affect dependent farmers. Worsening the situation further, India Meteorological Department (IMD) has warned of heavy rains in the state due to ongoing cyclone Ockhi.

In fact, the KRP dam breach has raised many questions and issues which need to be answered and addressed immediately.

About Krishnagiri Reservoir Project

The KRP dam is located at 12°29′37.44″N 78°10′41.51″E near Dhuduganahalli village in Krishnagiri district in Western Tamil Nadu. It was built in 1957 at a cost of ₹15.9 million for irrigational purposes on the Thenpennai river. The dam is about 1 km long 30 meters high and has a storage capacity of 509 thousand million cubic feet (TMC). It has 8 shutters and is maintained by PWD Govt. of Tamil Nadu.

Pennaiyar Basin
Pennaiyar Basin Map prepared by SANDRP

About Thenpennai River

Thenpennai river[III] is also known as Ponniar river , Ponnaiyar river or South Pennar River. It originates in the Chikkaballapur district of Karnataka state and flows through Dharmapuri, Vellore, Tiruvannamalai, Cuddalore and Villupuram districts of Tamil Nadu  before falling in Bay of Bengal. With a catchment of 3,690[IV] km2, the total length of the river is 400 km.  It is dry for the most part of the year but swells during the north east monsoon season.

penniyarbasin-copy
Pennaiyar Basin Map source WRD Tamil Nadu https://goo.gl/Kwea8z

About The Incident

On the day of the incident villagers living nearby observed a breach in shutter number 1 of the dam around 04:00 pm. Through them, the PWD officials came to know the incident 04:15 p.m. Gradually the breach widened and about 4000 cusecs of water started gushing through the dam by the night. Before the breach, downstream discharge from the dam was 316 cusecs.

As per official the pressure of water has damaged in the shutter causing the breach. As an remedial step, an additional 2000 cusecs was released through shutter number 5 to bring down the water velocity.  

 

How Much Water Is Flowing Downstream  

KRP 2
Water gushing out of shutter 1 as the breach remained to be contained in KRP dam in Krishnagiri, Photo Credit N. Bashkaran, The Hindu  

On November 29, about 6,000 cusecs of water was released from the damaged shutter number 1 and shutter number 5. On November 30, morning the discharge was increased to 12,000 cusecs using two more shutters number 2 and 3.

It was again reduced to 8,000 cusecs following high level expert visit during the day and shutters 6 and 7 were also opened.

Prior to the breach, the water level in the dam was reportedly at 51 feet as against the capacity of 52 feet. Interestingly, the dam had crossed the level of 50 feet in August month and there was a low flood alert already in place.

As per The Hindu[V] 30, 2017 the reservoir was filling up to its capacity after 8 years and has seen a consistent water level of 51 feet for last 3 months. It continued to receive copious inflow from the Kelavarapalli dam in Hosur, which is also reported to be in its full capacity.

As per latest report, the water level in the dam has come down to 46 feet on November 30, 2017. But to repair the shutter it is necessary to bring down the water level upto the height of 32 feet[VI] according to Deccan Chronicle report.  

What Are The Implications Of The Breach

The breach has brought sudden flash flood in downstream areas. Thousands of villagers living along the river have been caught unprepared. The riverbed farmers will be affected worst by the deluge.

The water was to be released during rabi season in January 2018. The breach would also cause dearth of irrigational water for around 25000 acres of farm land thus creating more distress for the farmers stressed already. It will also lead to shortage of drinking water in dependent villages and towns.

Under cyclone Ockhi, IMD has already issued warning[VII] of heavy rains in Tamil Nadu in addition to Kerala, Lakshadeep and Andamans. This may worsen the flood situation in the area.  

As per reports Tamil Nadu has been receiving rains for last three days hitting the normal life and a holiday was declared[VIII] for schools and colleges in five districts on November 30. The Thamirabharani river in Tirunelveli district is in spate due to incessant rains.

Who Is Responsible For The Breach

It is shocking that under DRIP program a stakeholders consultation Workshop titled an EAP was organised[IX] by CWC and Tamil Nadu Water Resources Department at Krishnagiri dam site only in August 31, 2017.

It is worth to mention that two “hydro-mechanical” works were carried out on KRP structure at a cost of ₹1.10 crore and ₹75 crore under DRIP in 2016. This includes repairing the girders used to support the shutters.

Another The Hindu report reveals that substandard quality[X] of material used during repair of shutters which has now led to the breach. As per the report the rubber sheets used to firmly set the shutters in the slot to prevent leakage were of low quality. Quoting an official on condition of anonymity, the report mentions that the low quality rubber sheet corroded causing increased pressure on the side of the shutter which ultimately resulted in breach.

It further states that Pudukottai-based contractor Pothigai Enterprises was awarded the contract for the KRP dam repair works under DRIP. The contractor reportedly has no website and is now untraceable. The Dam Safety Directorate’s website has listed the contractor name as Kan Abdul Kafar Khan of Pothigai Enterprises, but name of the repaired dam (KRP) is not mentioned.

Contrary[XI] to this Murugu Subramaniam, CE, PWD has stated that maintenance works was carried out only in the dam area including partial repairing of the shutters. A Times of India report quotes him saying that all the shutters have not been repaired in last 60 years.

As per his version the shutters became weak after 51 feet of water was stored in the dam for the last 102 days. He doubted a strong boulder like object hitting and weakening the shutter and held water pressure responsible for the breach.

Negligence And Corruption In Dam Safety Issue Is Unaffordable And Unacceptable

Dam safety is a matter of utmost concern in the country. In past many incidents of dam breach have occurred causing losses of lives and materials. KRP dam breach has once again raised the issues neglected for long.

As per Central Govt figures, India ranks third globally with 5254 large dams in operation and 447 large dams under construction. Meanwhile, about 4% of these large dams (209) are over 100 years old and about 17% (876 dams) are more than 50 years old. Many of these dams are facing varying degrees of inadequacies in meeting the current standards of dam health and safety due to various reasons.

Going through the account it appears to be a clear case of negligence exercised by all concern state level departments and central level agencies including PWD, Tamil Nadu and CWC.  

It is also oblivious that corruption in the repairing work under DRIP has taken place. The contractor awarded the work has no website and is out of contacts. Dam Safety Directorate’s website[XII] list the name of contractor but not the name which dam the contractor has repaired.

Officials have accepted that use of low quality material in the repair work. It puts a question mark on the function of State Dam Safety Committee (SDSC) and National Committee on Dam Safety (NCDS).

An independent inquiry must be conducted into the matter to deter the reoccurrence of such manmade disaster. All the involved officials found responsible of the breach must be made face prosecution and stringent punishment.

There are about 10 dams in the catchment of the Pennaiyar river basin listed in the national registry[XIII] of large dams. Most of them are 30 to 60 years old. A through safety audit of all these and other aging dams in the State needs to be conducted on urgent basis by the experts.

List of dams in Pennaiyar Basin
Table prepared by SANDRP

With the scores of aging dam in the country, dam safety issue deserves immediate attention. Their operation requires significant improvement and management needs to be transparent. There is also need to have Cumulative Impact Assessment (CIA) studies done and to keep disaster management plan ready for all the old dams in country. Otherwise KRP dam like breach will become a common scenario in coming years, taking huge toll on human lives and properties.

SANDRP (ht.sandrp@gmail.com)

Post Script:-

December 01, 2017:- Seeing the ongoing local rains in intervening catchment of KRP dam in Karnataka and Tamil Nadu and brewing system in the Bay of Bengal induced by cyclone Ockhi, CWC on December 01, 2017 has stressed on the need of ‘very careful monitoring’ the entire Ponnaiyar river system for next one week.

As per officials the forecast of rainfall in the area for December 2 and 3 is around 25-50mm in this area, may increase the inflow into the dam causing more discharge in downstream area.

“In the downstream of Sathanur dam as well as near the confluence with seas, the effect of the releases from Sathanur and the tidal effect from sea have to be monitored carefully,” the statement said. https://timesofindia.indiatimes.com/city/chennai/shutter-breach-in-krishnagiri-dam-ponnaiyar-river-must-be-monitored-for-next-one-week-cwc-says/articleshow/61879953.cms

December 01, 2017:- Inferring the passage of peak discharge CWC in its report mentions that since 29th November 2017 0600 hrs an average outflow of 170 cumec (6000 cusec) flowed through the spillway of Krishnagiri dam. There is also an inflow of about 10 cumec (350 cusec) into the reservoir. This reduced the water level by 1.2 m. Size of the spillway gate is 12.19X610 m. The height of the spillway is 6 m accordingly, if the same amount of discharge is maintained then it may take about 96 hours for the water to come down upto crest level of spillway. http://pib.nic.in/newsite/PrintRelease.aspx?relid=174033

Further the report finds that the KRP dam attained its Full Reservoir Level (FRL) in September 2017 following the very heavy rainfall in upper catchment of the river Ponnaiyar in Karnataka and Andhra Pradesh and started releasing water downstream. Due to this, the downstream dams also got sufficient inflow and Sathanur Dam located downstream KRP dam also attained FRL. Under this situation on 29th November 2017, one of the shutters of the Krishnagiri dam got damaged and water started flowing through the damaged shutter. http://pib.nic.in/newsite/PrintRelease.aspx?relid=174033

However the report does not mention that Kelavarapalli dam located in Hosur upstream of the KRP dam on November 29, 2017 was filled to 42.5 feet as against the total capacity of 44 feet and it continued to discharge abundant inflow to KRP dam. http://www.thehindu.com/news/national/tamil-nadu/shutter-breach-at-dam-triggers-flood-alert/article21130323.ece

Pennaiyar Basin CWC
CWC map of Pennaiyar basin 

As per CWC report Sathanur Dam located downstream of KRP dam was already near its FRL and anticipating the more inflow from KRP dam due to the damaged shutter, Sathanur Project authorities started releasing water from it 29th November 2017 evening.

December 01, 2017:- The average discharge since 29th November was approximately 64 cumec (2260 cumec). This has reduced the reservoir levels at Sathanur Dam by about 0.30 m. The available flood cushion at Sathanur Dam as on 30th November 2017 is 16 MCM (566 Mcft). The inflow likely to come during the next 96 hours with a constant discharge of around 170 cumec (6000 cusec) from upstream dam may be around 57 MCM(2073 Mcft). This means that Sathanur dam may have to release around 170 cumec (6000 cusec) for the next 4 days to keep the dam level around FRL. http://pib.nic.in/newsite/PrintRelease.aspx?relid=174033

December 01, 2017:- The impact of breach on downstream Sathanur dam has started appearing on December 01, 2017, as the inflow increased to 15,872 cusecs from 6 p.m. to 7.30 p.m. with an equal discharge into Thenpennai river. The water level in Sathanur dam has increased to 118.35 feet against the total height of 119 feet following water flow from the KRP dam and continuous rainfall. http://www.thehindu.com/todays-paper/tp-national/tp-tamilnadu/sathanur-dam-filling-up-water-released/article21246870.ece 

December 02, 2017:- In a closely guarded visit, a team from the CWC of dam safety specialists inspected the KRP Dam to ascertain the nature of damage in Shutter I. The team included Edward Eugene Flint, international dam safety expert, and A.K. Sachdeva, hydro-mechanical specialist – arrived here in their capacity as the consultants of DRIP funded by the World Bank and monitored by the CWC. 

Fwd-01deckgpvsG7P2VCFPV3jpgjpg.jpg
The CWC team that inspected KRP Dam in Krishnagiri. Dam specialists Edward Eugene Flint and A.K. Sachdeva are in the picture.N. BashkaranN_BASHKARAN 

However, the repair of the breached shutter or even repair or replacement of other potentially weak shutters will have to wait for fresh sanctions from the govt or multilateral funding agencies, said a source. The PWD’s immediate plan is to seal Shutter I and move on to storing water in the reservoir. The PWD has asked the contractor, Pothigai Enterprises, who carried out repairs to the dam in 2016 to seal the shutter. The repairs were done at Rs. 1.10 crore under DRIP. http://www.thehindu.com/todays-paper/tp-national/tp-tamilnadu/cwc-team-inspects-krp-dam/article21246256.ece

December 02, 2017:- Due to continuous rains in the catchment the damaged shutter of KRP dam could not be repaired till December 02, 2017 after three days of breach. Though the water level in the dam has come down at 36.30 feet from 51 feet at the time of breach yet officials feel that one more take would be taken to attain the target level of 20 feet necessary for carrying repair.

KRP dam is continuously releasing the water but inflow is also on the rise. On December 02, 2017 the inflow was at 2,658 cusecs and the outflow was 4,870 cusecs.

The drainage might be further delayed as the water level in Kelavarapalli an upstream dam is also increasing following rains in Karnataka. During first two days of month, Krishnagiri district and Hosur district have received an average rainfall of 42.44 mm and 40 mm respectively.  http://www.thehindu.com/news/national/tamil-nadu/rain-delays-krp-dam-shutter-work/article21251315.ece

05 December 2017:-  After the water level in the dam fell below 33 feet, PWD officials have started work on the damaged shutter on December 04. https://timesofindia.indiatimes.com/city/salem/work-to-repair-damaged-shutter-of-krp-dam-begins/articleshow/61922388.cms

KA06SHUTTERE-01.jpg
Works on dismantling shutter I in KRP Dam continued on Dec 05 (Photo Credit: N.Bashkaran, The Hindu)

06 December 2017:- The works on the dismantling of  24-feet high Shutter 1 went into a full-fledged mode. The shutter will be replaced by two 6-feet high plates, sealing the shutter gate up to 12 feet. Collector C. Kathiravan said that a proposal for the replacement of the shutter I will be put up to the State govt, along with the consolidated proposal to replace all eight shutters of KRP dam. http://www.thehindu.com/news/national/tamil-nadu/dismantling-of-shutter-gate-continues-at-krp-dam/article21271288.ece

19 December 2017:- Shutter thickness, corrosion led to KRP Dam breach It was found that the 24-feet metal plate of shutter number 1 had varied thickness – its top was 60 m, middle was 11 m, and the sill had barely 6 m of thickness. The breach was at the sill level. The highly corroded metal plate flags possible lapses in the inspection by the Central committee.

As per PWD official the CWC committee consisting of Central and State officials had reportedly inspected the dam superficially when the reservoir was full. The corroded part was submerged in water. The water pressure is at its highest at the sill level, and this is also where the metal was most corroded. There needs to be better interaction with the field level officials and the Committee to understand location-specific needs of dam safety.

KA19KRPDAM
Works to fix the shutter in KRP Dam under way in full swing on Monday.  Photo Credit: N. Bashkaran

The KRP Dam was inspected two years ago by a CWC to commission repairs under the DRIP funded by the World Bank. Repair works for ₹ 1.10 crore were accomplished on KRP Dam.

According to another PWD source, the water quality in Pennayar river is generally poor, with effluents drained from Bengaluru. Then, these location-specific factors were ignored and the inspection to designate works for dam safety was not comprehensive.

Post this incident, PWD has proposed to the govt to issue funds under the head of structural safety of dams which are currently allocated under “system maintenance”. These funds were utilised downstream for repair of sluices, and never for structural safety of the dam. The official also, works are taken up at the last minute with no proper study. http://www.thehindu.com/news/national/tamil-nadu/shutter-thickness-corrosion-that-escaped-inspection-led-to-krp-dam-breach/article21910144.ece

19 December 2017 Transparency need of the hour to ensure dam safety The KRP Dam breach and the draining of 1 TMC of water from the reservoir conflict with the mandate of the DRIP that funded dam safety works in KRP Dam.

The World Bank-funded – DRIP proclaims dam safety to enable water security and asset management, according to its web portal. Whereas, in this case the asset was not maintained and water security could not be ensured.

The usefulness of project under its current institutional form is questioned by dam safety experts. In the light of fresh information on the causes of the breach, The Hindu spoke to Himanshu Thakkar, coordinator, SANDRP and editor of magazine ‘Dams, Rivers & People’.

According to him, the piecemeal spending lends no real intervention to the structural or operational safety of the dam.

“Dam safety issue should be governed by greater transparency, participation and accountability. Today, it is a close club affair of Central and State govt officials, and some consultants appointed by them. Everything is secretive,” says Mr.Thakkar.

According to him, dam safety committees should have independent members, with minutes of the meeting, their decisions, and full information about the dam safety works in the public domain, with representation for two local communities.

On the possibility of chemical contamination and water quality, Mr.Thakkar underlines the dam safety mechanism for each dam to consider specific needs and terrain of each dam.

“This will address pollution and other operational issues. We also need coordination in dam operation across a basin, since unsafe operation or disaster at one dam impacts other dams in the basin.”

In the wake of KRP breach, an internal circular had been issued to inspect the structural safety of dams over 50 years in the State. There are 18 dams over 50 years old in Tamil Nadu.

According to Mr.Thakkar, ideally, this age-based categorisation and intervention should have been the first step under DRIP, even before the breach. http://www.thehindu.com/news/national/tamil-nadu/transparency-need-of-the-hour-to-ensure-dam-safety/article21910146.ece

End Notes:-

[I] https://en.wikipedia.org/wiki/Krishnagiri_Dam

[II] http://www.thehindu.com/news/national/tamil-nadu/shutter-breach-at-dam-triggers-flood-alert/article21130323.ece

[III] http://savethenpennai.blogspot.in/2013/09/about-thenpennai-river.html

[IV] https://en.wikipedia.org/wiki/Ponnaiyar_River

[V] http://www.thehindu.com/news/national/tamil-nadu/shutter-breach-at-dam-triggers-flood-alert/article21130323.ece

[VI] http://www.deccanchronicle.com/nation/current-affairs/301117/faulty-gate-opens-in-krishnagiri-dam.html

[VII] http://www.imd.gov.in/pages/press_release_view.php?ff=20171130_pr_160

[VIII] http://www.livemint.com/Politics/fAlWn5uVHFniAELmnJHpyO/Cyclone-Ockhi-intensifies-into-severe-category-to-hit-Laksh.html

[IX] http://pib.nic.in/newsite/PrintRelease.aspx?relid=170394

[X] http://www.thehindu.com/news/cities/chennai/what-led-to-the-mishap/article21239260.ece

[XI] https://timesofindia.indiatimes.com/city/salem/high-level-expert-team-inspects-krp-dam/articleshow/61871856.cms

[XII] http://tnwrd.gov.in/web/operation-maintenance-website/dam-safety-directorate

[XIII] http://www.cwc.nic.in/main/downloads/NRLD_04012017.pdf

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