Assam · Dam Induced Flood Disaster · Dams · Expert Appraisal Committee · Hydropower

Lower Kopili HEP: Oustanding issues that must be resolved before EAC can consider the project

The Lower Kopili Hydro Electric Project(HEP) will be considered for TOR clearance in the forthcoming Expert Appraisal Committee(EAC) meeting on September 23-24, 2013. This project was first discussed in the 63rd EAC meeting held on 12-13th October, 2012. It was again discussed in the 65th meeting of the EAC held on 26-27th December, 2012 for approval of Terms of Reference (TOR) for the Environmental Impact Assessment (EIA). EAC had sent back the project proposal seeking additional information/clarification on several issues. There were several critical issues which were not raised by the EAC. We have made a submission to EAC pointing out issues which need urgent attention.

Background of Hydroelectricity Generation on Kopili River

The Kopili River: Kopili is a south bank tributary of Brahmaputra which originates in the Borail range mountains in Meghalaya at an altitude of about 1600 m and has a total length of 290 km up to its confluence with Brahmaputra. Its basin is bound by the Jaintia Hills in the west and the South Cachar and Mikir Hills in the east. Kharkor, Myntriang, Dinar, Longsom, Amring, Umrong, Longku and Langkri are its major tributaries in its upper reaches.

After entering Assam the Kopili separates the Karbi Anglong district from the Dima Hasao North Cachar Hills district up to its confluence with Diyung River on its right at 135 km. After the confluence with Diyung, Kopili flows into the Nagaon district in a north-westerly direction. The Jamuna River with a catchment of 3960 km2 flows to the Kopili at Jamunamukh. The river then flows in western direction, and further downstream, the Umkhen-Borapani River which rises in the Shillong plateau and drains an area of 2038 km2 joins Kopili at a distance of 254 km from the left. The Killing River, known as Umiam in its upper reaches draining an area of about 1445 km2, flows into Kopili from the left at about 280 km. The Kopili River finally flows to Kalang, a spill channel of Brahmaputra, near Hatimukh after traversing a distance of 290 km2. The total catchment of Kopili River is about 16,421km2.

Kopili HEP: The Kopili Hydro Electric Project (HEP) has two dams, one on the Kopili River and one on its tributary Umrang stream. This project was developed by NEEPCO (Northeast Electric Power Corporation Ltd.). The first dam with 66 m height on the Kopli River is known as Khndong dam and the second one with 30 m height is known as Kopili dam located at Umranso.  Water from the Khandong reservoir is utilised in the Khandong power station through a 2852 m long tunnel to generate 50 MW (2 X 25 MW) of power. The tail water from this powerhouse is led to the Umrong reservoir. The water from Umrong reservoir is taken through a 5473 m long tunnel to the Kopili power station to generate 200 MW (4 X 50 MW) of power. An additional 25MW was added to the Khandong dam in the Stage two of the Kopili HEP, making the total power generation 275 MW. Both Khandong and Kopili dams are concrete gravity dams. The first unit of this Kopili HEP was commissioned in March 1984. Additional unit under stage two was commissioned in July, 2004.

Proposed Lower Kopili HEP: The proposed Lower Kopili HEP is coming up in Boro Longku village in Dima Hasao district. The project is developed by Assam Power Generation Corporation Limited (APGCL). The Lower Kopili dam will be a concrete gravity dam with 70.13 m high dam wall. This project will also have two power houses and the first power house, or the main power house will have an installed capacity of 110 MW (2X55MW). An auxiliary Power House with an installed capacity of 10 MW (2×2.5 MW+1×5 MW) has been planned  at  the  toe  of  the  dam  for  utilizing  the  mandatory  releases  for  ecological purposes, making the total installed capacity 120 MW. The Head Race Tunnel(HRT) of the project will be 7.25 m in diameter and 3.6 km long. The total land required for this project will be 1577 ha out of which according to the revised PFR and Form-I 552 ha will fall under submergence. But the old PFR and Form-I had mentioned the size of the submergence area as 620ha. The  free flowing river  stretch  between  Full Reservoir Level  (FRL) of  Lower  Kopili  HEP  and  Tail Water Level (TWL) of upstream  Kopili  HEP  is  about  6  km.

The water available at Lower Kopili dam site will consists of the following components:

1.   Tailrace releases from Kopili Power Station (4 x 50 MW)

2.   Inflow from intermediate catchment between Khandong and Longku Dam site

3.   Spill from Khandong and Umrong Reservoir.

Projects in Cascade on Kopili River
Projects in Cascade on Kopili River

Some Key Issues Requiring Urgent Attention

After thoroughly going through Pre Feasibility Report (PFR) and Form-I of the proposed Lower Kopili HEP we have found that following issues have not been adequately dealt with by the project authorities. Infact some of them have not even been mentioned at all. EAC should not give TOR clearance to the project without satisfactory resolution of these issues.

Dam induced Flood: Experiences of the people living in downstream suggest that floods have become more recurrent after construction of the dam. The Kopili dam has changed the character of flood in the river downstream for the worse. Before the construction of Kopili dam, floods occurred mainly during monsoon season. Increase in water volume due to heavy rains used to be the reason for flood. These were normal floods which occurred not more than two or three times a year. But after the construction of the dam, number of artificial floods occurring in a year has gone upto 5- 6 times. These floods mainly occurred from the month of August to the first one or two weeks of November. Government of Assam never made an attempt to investigate the source of these floods (this information is from a field visit done to the area). 

In the catastrophic floods of 2004, out of 140 revenue villages of Kampur circle of Nagaon district 132 were affected by floods with area of 135.12 sq. miles. Due to these floods 1,92,000 people were temporarily displaced. These floods also took the lives of 4 people. Even government had confirmed that the main reason for the devastation in these Nagaon and Morigaon districts was the release of the water from the NEEPCO’s Kopili project. The team that was deputed by the government found that water level of the Khandong reservoir went up to 727.70 meters against the FRL of 719.30 meters on 18th July 2004, which rolled down and led to catastrophic disaster. Flood release from the dam happened without prior warning and affected the whole valley. Kampur is one of the towns located in the downstream of Kopili dam where people were give only 2 hours to evacuate the area and move to nearby relief camps.  July 18 is less than midway through the monsoon and questions arise why was the dam allowed to be filled up so soon which had led to such disaster. Had the dam operations were conducted properly the disaster could have possibly been avoided.

The issue of flash floods in Kopili River was raised in the Assam state assembly. On 8th November, 2010 former Chief Minister of Assam Mr. Prafulla Kumar Mahanta, an MLA from Nagaon district made a call attention motion in the Legislative assembly on the issue flash floods in Kopili. He stated the NEEPCO is responsible for the flash floods in the Kopili River.[1] Then Water Resource Minister Prithvi Majhi in his reply accepted this claim by saying that “the government would take up the matter of providing prior warning before release of excess water with the NEEPCO authorities.”  From the above experiences of flood in Kopili River, it is clear that after the construction of the Kopili HEP (Hydroelectric Project) flood ferocity had increased in the downstream. In such situation construction of another dam in the immediate downstream of previous dam can worsen the flood scenario.

Besides, The Kopili reservoir of the Khandong dam is located at 82.5 km downstream from the origin of Kopili River. A major tributary Myntang with 512 sq kmcatchment joins Kopili at 86 km from origin[2]. This is one of the tributaries in the upstream of proposed Longku dam site. In rainy season excess of rains in the catchment of these streams can also lead to spillovers in the proposed dam itself. The PFR does not look into the cumulative impact of the operation of the two dams on the downstream riverine area.

Spillway Capacity Inadequate at Lower Kopili HEP: As per the PFR, the design spillway capacity of the proposed Lower Kopili project with catchment of 2106 sq km is 16110 cumecs. Compare this with the spillway capacity of the upstream Khandong dam on the same Kopili river with catchment area of 1256 sq km being 15471.3 cumecs. It is clear that the design spillway capacity of the proposed Lower Kopili Project is inadequate.

Acid Contamination due to Opencast Mining threatens Viability of Lower Kopili: In the item 9.9 of the Form-I it has been mentioned that the acidic mine discharge in the upper reaches of the Kopili catchment is posing serious threats to the existing Kopili HEP. The PFR states “The identified acid mine discharge has been reported to cause constant erosion/ corrosion of critical hydropower equipments leading to frequent outages of the power plants under Kopili HEP.” The minutes of 9th TCC (Technical Coordination Committee) & 9th North East Region Power Committee Meetings held on 11-12th August, 2010, stated “The Kopili HE Plant has faced an extraordinary and unprecedented situation owing to acidic nature of the reservoir water. Prima facie, the acidification of the reservoir water is caused due to unscientific coal mining in the catchment area as revealed by study through GSI, NER, Shillong. The increased wear and tear on the underwater metal parts of the Plant due to corrosive action of the acidic water has led to the increase in the number of breakdowns.” The minutes also mentioned “It is pertinent to mention here that, although massive repairing work has been carried out by NEEPCO as temporary measures; an integrated, interdisciplinary approach for preventing / tackling acidification at source must be opted for survival of the Plant.” The acidic contamination due to open cast mining is such that no living organisms could be found in the downstream of Kopili river up to Kheroni.[3] The situation is quite alarming as the PH value of the water has come down from 5.5 to 3.2 due to acidic contamination which is unfit for human consumption. State Power Minster was very much aware of the situation and expressing concerns over this he had asked the center to take up this issue with Meghalaya.[4] The PFR should have given detailed account of implication of this on the proposed Lower Kopili HEP and further downstream, but has not done that.

PFR overlooks Kopili Fault Line: The PFR of the proposed Lower Kopili HEP does not mention about the Kopili fault line[5]. In recent studies done in the Kopili river basin it has been found that the Kopili fault extends  from  western  part  of  Manipur  up  to  the  tri-junction  of  Bhutan,  Arunachal Pradesh  and Assam, covers  a  distance  of about  400 km. During the last 140 years, the Kopili fault has experienced 2 earthquakes of magnitude greater than 7 in R.S., three of magnitude 6 to 7 in R.S. and several of magnitude 4.5 to 6 in R.S.[6]   The study concludes that the North East region, more specially the Kopili Fault area is a geologically unstable region, surrounded by faults and lineaments and seduction zones in the east.  But the PFR of Lower Kopili, overlooking this issue states that there are only two minor faults in this area and both of them are much beyond the project area. This clearly wrong and misleading on the part of Lower Kopili PFR.

Besides, some of the EAC statements are not complete and stand in contradiction to each other. The EAC said that as the site specific seismic study had been completed by IIT Roorkee and considered it appropriate for 120 MW project. But it also mentioned “The project specific geo-morphological and neo-tectonic mapping has not been done so far. As the project area falls under the active seismic zone where the Disang-Naga Thrust and Dhauki fault merge which triggers high seismic risk, the proponent is to monitor the MEQ studies by installing a 3-4 seismograph network for a period of one year.” When EAC is aware of these site specific details, allowing an additional big dam in the area will only to increase disaster potential in the area. EAC needs to keep this in mind while considering this new dam.

Issues Tribal Land Relations: In the item 2.1 of the Form 1 the project authorities have stated that the 620 ha that will be submerged due to this project consists of medium to high density vegetation, scrubs open and barren land etc. But Dima Hasao people have expressed their fears of not getting proper rehabilitation.[7] The project seems to ignore this fact in the form 1. There can another reason also for the stating the submerged land as government land because the land holdings may not same as the ‘patta’ lands.[8] Besides, the area which has been considered for the construction of the dam is inhabited by Dimasa people who mainly depended on the system of shifting cultivation.[9] It is to be noted that in shifting cultivation there a cultivator cannot exercise permanent ownership over the land.

Defining ‘Other Forests’: The project as stated in item 1.1 of form 1 will also submerge 65 ha cultivation land. In the same item it is mentioned that an area of 585 ha will be submerged and this area has been mentioned as ‘other forests’. But the Form 1 did not define what this ‘other forests’ are or what they consists.

Impact on the Local People: In a memorandum submitted jointly by the Karbi Students’ Association (KSA), Sominder Kabi Amei (SKA) and Karbi Nimso Chingthur Asong (KNCA), to the State Power Minster Mr. Praduyut Bordoloi, the association demanded first preference in terms of employment should be given to the locally affected people. But the track record of dam building companies is very poor in this regard. The local people did not get promised employment and other benefits the in the Kopili project which came up in 1970s, 1980s and 1990s. On 20th March 2012, the Dimasa Students’ Union, Dimasa Welfare Association, Karbi Students’ Association and Sengia Tularam Club called for a 48 hours Umrangso bandh seeking “60 per cent of technical and non-technical posts in the project should be reserved for the local tribal populace, 100 per cent reservation for local tribal youths for Grade III and Grade IV posts, free electricity for locals, free treatment facilities in NEEPCO-run hospitals and so on.”[10] This is very crucial issues but surprisingly it finds no place in the PFR document.

Why the size of forest area significantly reduced: In the revised Form I and PFR, submitted on 23 August 2013, Section 1.1 mentioned that out of 1577 ha which is the total land required for the project, 552 ha will fall under submergence and 340 ha forest land will  be submerged in the reservoir. But the previous Form I and PFR, submitted on 14th November 2012, stated in the same section that the land falling under submergence and land converted into reservoir area is same i.e. 620 ha. The revised document does not give any rationale for reducing size of submergence area and reservoir area. It is also surprising to note that in the revised document, under the section “Impacts due to damming of river” in page 55, the old figures of submergence has been reiterated – “The  damming  of  river  Kopili  due  to  the  proposed  hydroelectric  project  in  creation  of  620  ha  of submergence  area.” So the new documents submitted in Aug 2013 have serious contradictions.

Issues Need to be Included in EIA report

Since several critical issues were not included in the previously submitted document, we have listed out the following issue which should be included in the Environment Impact Assessment (EIA) study of the proposed Lower Kopili HEP. Without detail analysis of all these issues EIA cannot be considered as complete.

Downstream Impact Assessment:  Downstream impact assessment is a burning problem in Assam. The state has already witnessed huge protests against dams due to lack of proper downstream impact assessment. In case of proposed Lower Kopili HEP, the EIA document should do a proper downstream impact assessment. In order to do a thorough downstream impact assessment, the EIA will have to go beyond the 10 km radius and assess the full downstream area. In case of Lower Kopili, going beyond 10 km downstream becomes all the more significant because major part of the Kopili river basin is in the downstream of the dam. The downstream impact assessment should specifically focus on the impacts of the dam on fisheries and livelihood of the people who are dependent on fisheries, change in character of flood and impacts thereof, change in sedimentation and impacts thereof, change in geomorphological issues, change in groundwater recharge, among others. The EIA should find which section of people will be affected the most by the dam and how to compensate those people.

It has been reported that bank erosion by the Kopili River has increased after the construction of the Kopili dam. The EIA report of Lower Kopili HEP, should do an analysis to find what will be impacts of the new project on river bank erosion.

Impacts Peaking Power Operations: The EIA should do a detail assessment of impacts of peaking power operation during non-monsoon months. Due to peaking power generation in non-monsoon months the river stretch downstream from power house will have very little water for most hours of a day with sudden flows in the river only for a few hours. This flow fluctuation leads to many severe impacts including on aquatic bio-diversity, on safety, on river bed cultivation, on erosion, among others. This has severe socio economic impacts along with issues of safety of the people and their livestock in this stretch of the river. Therefore the EIA should do a detail assessment of impacts of peaking power generation.

Assessment of Optimum Reservoir Operation: The EIA should do an assessment to prepare an optimum reservoir operations plan for the project in order to minimize the downstream impacts if a disaster occurs. It is also highly recommended that the local people should be made a part of the reservoir operations process. Then only the dam authorities can be expected to be more responsible to in reservoir operations.

Impacts of Silt Management operations: The EIA should include detail analysis impact of changing silt flows downstream from desilting chamber, from silt flushing in monsoon, on the downstream areas. The EIA study should give detailed account of how the silt from the dam will be flushed out annually and what will be the impact of this in the downstream. The EIA should also include how the desilting chamber will be operated and what will be its impacts.

Detailed and Thorough Options Assessment: The EIA should do a thorough options assessment for the project. There can be several other cost effective options for power generation in that area and options assessment should look into al those.

Here we can take the case of solar power. A recent example of proposed 1000 MW solar power generation in Rajastan[11] has showed that for 1 MW installed capacity only 2 Ha of land is required and the cost per megawatt installed capacity will be 7.5 crores and electricity will be provided at Rs 6.5 per unit. Another proposed 25 MW solar power project in Assam[12] has similar figures.

At this rate, for a 120 MW (the target capacity of the proposed Lower Kopili HEP) solar power plant, the land required will be 240 ha. But for Lower Kopili HEP the land required is 1557 ha of land out of which nearly 900 ha will be used for the project even if we subtract 680 ha projected to be used for compensatory afforestation. This implies that for 1 MW installed capacity for the proposed dam the land requirement will be about 7.5 ha, about 3.75 times the land required for solar project of same capacity. Besides, the total cost for the Lower Kopili project is expected to be Rs. 1489.64 crores implying cost per MW installed capacity will be Rs. 12.41 crores, compared to Rs 7.5 cr for solar plant. Even if we were to put up 240 MW installed capacity of solar project, it would require 480 ha land, will not have impacts on the river, on people’s livelihoods, on forests, on climate change, and so on.

Increased Costs: It is important to note here that EAC in its 65th meeting in March 2013 discussing this projects had noted “In  comparison  to  other  HEPs  being  examined  recently,  the  cost  per  unit  of installed capacity of this project is almost double!” and this was said when the cost per megawatt installed capacity was Rs. 9.79 crores. Now in the revised document, the cost has gone up further to Rs 12.41 cr, the project proponent need to explain this further escalation from the earlier already high cost.

Groundwater Depletion in Downstream areas: People in the downstream of Kopili dam have reported that there has been depletion of groundwater in the downstream areas of Kopili dam. From a field visit done in the downstream areas of Kopili dam, it was reported that the ground water level at certain areas had reduced to 140 feet. River like Borapani, Kopili and Nisari dry up in the winters affecting the winter cultivations. Besides, wetlands which are known as Beel or Duba locally have disappeared. The reduction in groundwater can also be due to reduced groundwater recharge due to the dam. Impact of the dam on groundwater recharge should be a part of the EIA study.

Impacts of Tunneling and Blasting: The EIA should analyze the impacts of tunneling and blasting as these activities can increase in risk of landslide and disaster in a hilly area. Blasting in hilly area also will have impacts on water and people. These impacts should be thoroughly assessed by the EIA of the proposed project.

Impacts of Mining: The project will require large quantities of sand, coarse and fine granules and boulders. These are likely to be mined from the nearby areas. The EIA should include a study on the impacts of mining on the people as well on the local environment. Mining for the project will be done in the nearby areas and it will have severe impact on people as well as on the river, bio-diversity, hills, flora-fauna and aquatic bio-diversity etc. The study on the impacts of mining should include all these issues.

Impacts of Backwater Effects: The PFR of proposed Lower Kopili HEP states that Maximum Water Level (MWL) of the river is 229.60m where as the FRL of the reservoir is 226.0m. The MWL is thus 3.6m higher than FRL and this will have serious back water effects during the times of monsoon. The EIA must do an assessment of the submergence at MWL level and backwater effect measured at MWL and follow it up with an impacts analysis.

Detailed analysis about the existence of wetlands, watercourses and other water bodies: The revised PFR in page 17 under section ‘Environment Sensitivity’ states that there are no wetlands, watercourses and other waterbodies reported within the 15 km of the project. This statement seems incorrect. The EIA should do a detailed and thorough analysis regarding the existence wetlands, watercourses and other water bodies within 15 km of the project site.

 Impacts of Climate Change: The EIA of the proposed Lower Kopili dam should do a study of  possible impact of the climate change on the dam as well as on the Kopili river. Besides, it should also include the impacts of the dam on adaptation capacity of the local people.

Smaller Size Documents should be Uploaded for Public Dissemination: The EIA and other documents which would be uploaded on the internet should be about the size of 10 MB or less. The Revised Form I and PFR which uploaded on the MoEF website was 114 MB and it was difficult to download such a huge document even in a metropolis. These heavy documents will nearly be impossible to download from a small town or a village. The MoEF should insist from projects proponents that PP should be careful about this and should reduce the size (less than 10MB) documents for uploading from next time.


Parag Jyoti Saikia

with inputs from Himanshu Thakkar and Pooja Kotoky

Email –

South Asia Network on Dams, Rivers & People (

[2] Patowary, A., “The Kopili Hydroelectric Project, Downstream People Rise in Struggle” published in “Water Conflicts in Northeast India – A Compendium of Case Studies” edited by Das, Partha J. et. all, 2013

[5] Mahanta,  K. and et all (2012): “Structural Formation & Seismicity of Kopili Fault Region in North-East India and Estimation of Its Crustal Velocity” International Journal of Modern Engineering Research,Vol.2, Issue.6, Nov-Dec. 2012 pp-4699-4702

[6] ibid

[8] It is to be noted that in many of the tribal areas of Assam and India’s north eastern states, the tribal law of land is community of ownership of land and there are no government ‘patta’ system.