(Feature Image: Mahan III HEP powerhouse in flooded condition due to overflowing of dam. Image Source: Dainik Bhaskar)
The powerhouse and dam of Mahan-III Hydroelectric Project (HEP) in Chhattisgarh have faced significant damages due to floods during intermittent rainfall in the catchment of Mahan river in the 1st week of Aug 2024. As per the reports, the HEP dam overflowed and breached adjoining embankments because the project authority failed to open its gates in time.
The 24.75 Mw project is developed by Venika Hydro Power Project Ltd near Chikini village under Odgi (also spelt as Oudgi & Odagi) block of Surajpur district in Chhattisgarh. Work on the Run of the River (RoR) project started around 2011, and it was commissioned in Nov 2019. The dam is about 21 meter high and about 400 meter long including 70 meter and 20 meter long earthen embankments on right and left side of the main dam respectively.
The powerhouse of the project is located just downstream of the dam on the left bank of the river. The dam has 9 hydraulic gates, and the project authority failed to open any of the gates before the flood spell hit the site.
The dam started overspilling from the evening of Aug 1, 2024. Next day, the flood water started overflowing the dam structure. The reservoir level increased hugely, creating submergence threat for a dozen villages in upstream. Also, the dam failure appeared imminent posing safety threats to habitations in downstream areas.
Given gravity of the situation, the district administration started vacating Lanjit, Kuppa, Chikini, Bijilidand, Mayurdhakki, Gangotri, Kodhapurva, Souhar villages and also appealed to villagers to move to higher areas and stay away from the river. The Balhipani villagers who only have the dam structure to cross the river were particularly trapped in rising water of the flood.
After flowing over the dam structure for about two days, the flood severely eroded both the earthen embankments of the dam. The breaching gradually brought down the flood level and reduced pressure for the main dam structure.
However, before this, the deluge had completely submerged the powerhouse of the HEP causing extensive damages to its building, turbines, equipment and machineries. The destruction to dam embankments and powerhouse has resulted in financial losses worth crores to the company.
Currently, the HEP is out of operation and restoration work could take at least half a year. This You Tube video shows overflowing of dam flooding powerhouse of the project and while this ground report by Inside Story shows the powerhouse of the HEP in ravaged condition.
Disaster Management in Shambles
The villagers blamed the project management for exercising negligence in maintenance of dam gates. As per them, had the project officials checked the gates before the monsoon, the disaster situation and destruction could have been avoided.
Though there is no official report either by the administration or by the project company available in public domain on the incident, the media reports mentioned that the gates of the dam could not be opened due to a technical fault and trip in power supply.
“I was on leave that day hence could not prepare a report on the incident” said Pradeep Singh Kanwar the Public Relation Officer (PRO) of the district. He further stated that the project company has been investigating the causes behind the incident. Despite request he even refused to share the contact numbers of concerned government and project officials.
As per Sagar Singh, SDM, Bhaiyathan the administration has no initial report on it. “We informed the District Collector (DC) telephonically following that the DC conducted a field visit to the area”, responded the SDM. When asked why the administration has not been probing the incident, the SDM informed that the Water Resources Department (WRD) has set up inquiry to investigate the causes of dam’s gates failure.
“Officials from Dam Safety Organization from Raipur have visited the site but have not shared the report with us so far”, stated Chandra Bhanu Dhruw, Executive Engineer (EE), WRD, Surajpur district. As per him, the incident could be a result of lack of maintenance of the dam gates. He further mentioned that the flood overflowed the dam structure for about 48 hours.
“We are waiting for incident report from the Venika company before finalizing our report. After which we will share the report with National Dam Safety Authority (NDSA)”, responded Arun Badhiye a dam safety official in the state adding that the dam will be included in projects listed under Dam Safety Act (DSA) 2021.
During visit to the project site, he was informed by the company officials that they had opened all the gates of the dam and passed flood spell on July 31, 2024. But the gates became dysfunctional next day. “The powerhouse is totally damaged”, said Arun Badhiye. He felt that the hydraulic system might have failed due to lack of oil (lubricant) in the gates.
Disappointingly, the disaster management page on the Surajpur district website is totally blank. Similarly, Rohit Vyas, DC, Surajpur and official from Venika company did not attend phone calls made to seek some basic and relevant information about the incident. We have emailed the questions to them and will update the report if we receive replies on the same.
It is noteworthy that the Mahan-III HEP incident is followed by NDMC’s Iron Ore dam induced flood disaster in Dantewada district of the state in July 2024. In that case too the administration has so far not made the inquiry report public. It appears, this incident will go the same way, suggesting the concerned government departments and project proponent have no intention to draw essential lessons from the avoidable disasters time and again.
It is worth mentioning that the Mahan-III is part of a cluster of 6 HEP projects namely Mahan, Mahan-I, Mahan-II, Mahan-V and Gangotri and in addition to Mahan-III, the Venika group is also pursuing 24.75 Mw Mahan-II and 9.99 Mw Mahan-V HEP projects on the Mahan River in the region.
In May 2012, SANDRP had objected to CDM credits for the Mahan-III HEP, as the company had submitted several misleading and wrong information to get CDM benefits. Additionally, as per the minutes of 48th meeting of Expert Appraisal Committee (EAC) on River Valley and HEPs held in June 2023, the dam of the Mahan-III will be used as lower reservoir for the proposed 325 Mw Chikini pump storage hydro project.
Bhim Singh Rawat (bhim.sandrp@gmail.com)
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