Concerns over Sillahalla hydroelectric project coming up in the ecosensitive Nilgiris

Bembatty village where the upper reservoir of the Sillahalla hydroelectric project is expected to be located. Photo by Mathimaran.

Bembatty village where the upper reservoir of the Sillahalla hydroelectric project is expected to be located. Photo by Mathimaran.

  • The Sillahalla Pumped Storage Hydro-Electric Project aims to construct two reservoirs in the Kundah region of Tamil Nadu’s Nilgiri district. A tunnel would be made to connect the two dams and water from the lower dam will be pumped to the upper dam to generate electricity mainly to address peak time deficiency.
  • Environmentalists and local communities are opposing the project on the grounds that it will be an environmental and livelihood disaster submerging nearly 800 acres of dense forests and prime agricultural lands, along with displacing over 10,000 people.
  • An ecologically fragile land, the Nilgiris is already facing enormous threats from illegal constructions and large scale encroachments.

The mountainous Nilgiris district in Tamil Nadu is now witnessing an ecosystem collapse mainly due to extreme weather events. Floods that are happening almost every year are causing major landslides and slope destabilisation. The last remaining wild spaces are shrinking as illegal constructions and large-scale encroachments are turning contributing factors in this damaged Western Ghats stretch.

“Among the ecologically fragile areas of the district which are prone to the annual floods and landslides, the Kundah taluk region, located about 24 km from district headquarters at Ooty, is the most vulnerable. The extreme precipitation event (2400 mm of rainfall over four days) that happened in August 2019 had caused hundreds of landslides in Kundah watershed region alone. During the 2020 rainy season, 457 people lost their homes in landslides and deluge,” pointed out V. Durai, a farmers’ leader from Bembatty village in Kundah.

According to him, his village along with Kallakorai, Manjoor, Kattadimattam, Thuthalai, Kanneri, Thangadu, Oranalli, Meekeri, Muthorai Palada and Balocola would be affected in the coming years once the storage reservoir of a controversial mega hydel power project is a reality. The power project, which is projected to cost Rs. 49.52 billion, is now under implementation and threatening to cause further collapses and destabilisation of the highly vulnerable Western Ghats region. Other than causing irreparable damage to the flora and fauna of Nilgiris, the project is now being viewed as a major threat in terms of large scale livelihood destruction and rendering of a large number of agrarian families homeless.

The only temporary reprieve is union government’s recent decision to conduct an environmental impact assessment study and public hearings involving locals and environmentalists before allowing the state government to proceed with the project.

Two reservoirs, tunnels and a powerhouse

As per information available with the project proponent, the Tamil Nadu Generation and Distribution Corporation Limited (TANGEDCO), the Sillahalla Pumped Storage Hydro-Electric Project (SPSHEP) aims at construction of an upper reservoir measuring more than 260 feet in height in Bembatty village along the Sillahalla stream, a tributary of Kundah River, a major feeder of state’s second largest river Bhavani. A lower reservoir with more than 350 feet in height will be built further downstream, past the existing Kundah Dam.

A 2.8 km head race (bringing water to the powerhouse from the upper reservoir) and a 1.56 km-longtail race tunnel (taking water from the powerhouse to the lower reservoir), with a diameter of nearly 10 metres,would be constructed  to connect the two dams. Electricity would be generated by pumping water from the lower dam to the upper dam, says the project report. The Sillahalla hydroelectric project seeks not only to dam the Sillahalla but also to interconnect the proposed dams with the nearby Avalanche-Emerald Reservoir, which is also located at the same level. The project also includes construction of both a surface storage point and an underground power house.

As per TANGEDCO’s ownestimate, the proposed project will apparently submerge more than 315 hectares of forest, private and government lands once the reservoirs turn fully functional.

In a statement to the press, environmental lawyer B.J. Krishnan, a member of the Western Ghats Ecology Expert Panel-WGEEP, had stated that nearly 800 acres of rich green cover will be submerged in water if the project is implemented fully. In addition, more than 10,000 native people, mainly agrarians, will lose their nature-based livelihoods.

“Officials have already told us that the dam will submerge all of our agricultural fields along with surrounding dense forests. We have been cultivating potatoes, garlic and carrots here for generations along with tea and we have no other place to go,” said Durai.

As per TANGEDCO’s estimates, the project on completion will add 1,000 megawatts to the power grid for use during peak hours in Tamil Nadu, which presently struggles hard to address power deficiency.

Surplus water from the existing Kundah dam being let out through the Sillahalla stream during August. Photo by Mathimaran.
Surplus water from the existing Kundah dam being let out through the Sillahalla stream during August. Photo by Mathimaran.

Environmental concerns and protests

With the government announcing the project’s implementation and the TANGEDCO refusing to even acknowledge the environmental and livelihood concerns, a large number of local residents and environmentalists have started sending online petitions in the recent days to the expert appraisal committee (EAC) of Union Ministry of Environment, Forest and Climate Change (MoEF&CC) seeking to reconsider the terms of reference (TOR) clearance for the Sillahalla hydroelectric project.

“In the given situation of environmental decline, it would be disastrous for the entire Nilgiris to undertake construction works of underground tunnels that stretch for kilometres. Such tunnels are already in existence in the case of the Kundah hydel power project which came up years ago. Now, yet another huge tunnel is going to be constructed along with a few minor ones. The tunnel along with two more dams of SPSHEP will further endanger overall safety and environmental sustenance of Nilgiris,” B.J. Krishnan told Mongabay-India.

At present, there are ten dams in the Kundah-Bhavani system and they have caused severe ecological impact in the case of Nilgiris. “Now two new dams are being planned on tributaries of the river with significantly lessened water flow. On implementation, the dams and the tunnel would influence the ecology and hydrology of the Kundah watersheds. Diverting water from the catchments which witness high rainfall and changing the course of the water flow will further escalate the ecological and hydrological impacts that are already present,” Krishnan pointed out.

TANGEDCO officials when contacted by Mongabay-India said the project would impound approximately 4.2 thousand million cubic feet (TMC) of water in a year. The inter-connecting tunnel will have a provision for two-way flow. As per expectation, Sillahalla power plant will cater to peak hour demand. The proposed new dams would also act as balancing reservoirs between the Avalanche-Emerald dam and the downstream Pillur dam.

Environmentalists say the area in which the Sillahalla Hydro Project coming up is contiguous to the Silent Valley National Park, the Mukurthi National Park and the Nilgiri forest division. It is widely regarded as a unique biodiversity rich eco-sensitive zone. “Already there are ten large dams and reservoirs in the Kundah-Bhavani basin and the area has already reached its ecological carrying capacity. Execution of the Sillahalla hydroelectric project will adversely affect the integrity of the fragile mountains with adverse consequences, both ecological and social,” said K. Mohan Raj, a Coimbatore-based environmentalist.

According to K. Jayachandran, a local activist, the project site falls within the draft Western Ghats Eco Sensitive Area and the distance from here to Mukurthi National Park would be hardly 3.49 km. The distance to Mudumalai-Mukurthi tiger corridor is just 4.1 km.

According to restoration ecologist Vasanth Godwin, a thorough assessment of the possible impact of the hydroelectric project on the environment of Nilgiris must have been conducted before proceeding with the proposal. “The ecology and environment of Nilgiri are very fragile. The project site is situated in an area that is rich in biodiversity and sustains a whole environmental ecosystem,” he adds.

Environmental activists and local community confirm that the project site is home to endangered species of wildlife including Nilgiri tahr, Nilgiri marten, Nilgiri langur, Nilgiri laughing thrush, Nilgiri pipit, horseshoe pit-viper, rusty spotted cat, leopard cat, mouse deer, barking deer, dholes, leopards and tigers.

Read more: When the grass was green – Todas of the Nilgiris long for their lost grasslands

Vegetable farms in Thuthalai village which could be submerged due to the project. Photo by Mathimaran.
Vegetable farms in Thuthalai village which could be submerged due to the project. Photo by Mathimaran.

Sillahalla hydroelectric project will add to district’s vulnerabilities

In July this year,  374 environmental activists from across the country had issued a public appeal to the Union Ministry of Environment, Forests & Climate Change (MoEF&CC) appraising it that the region where the project has been planned is not only ecologically fragile but is also prone to landslides. The activists urged upon the central government to scrap the project because it could have huge social and environmental costs.

Since 2007-08 the TANGEDCO has been in the process of constructing a hydroelectric project across River Sillahalla and that too at a distance of less than 2 km from an existing dam of 60 MW Kundah Power House I project.

“The area has a number of indigenous people who would lose their traditional dwellings with the construction of the dams. The local farming community will also suffer. The southern slopes of the Nilgiri plateau are dry and rain-shadowed. Their water security will also be in peril once the project gets commissioned,” said environmentalist Mohan Raj.

As almost all areas of Nilgiris are prone to landslides resulting from heavy precipitation, there is widespread fear that the project could meet with accidents in the future. As tunnelling is an integral part of the project, it may result in the weakening of hillsides thereby making it susceptible to collapse during heavy rainfall.

A study conducted by the Geological Survey of India after the floods and landslides of August 2019, estimates that the number of vulnerable locations in the Nilgiris has gone up from 101 in 2001 to over 300 in 2019.  Large landslides have been recorded near the cable-cum-ventilation Tunnels for the existing Kundah hydro power project in the recent days with the construction of large service road damaging rich shola-grassland ecology.

The Emerald Dam, which would be linked to the Sillahalla project. Photo by Mathimaran.
The Emerald Dam, which would be linked to the Sillahalla project. Photo by Mathimaran.

Environment ministry suggests new conditions

On July 29, the Expert Appraisal Committee (EAC) of the Ministry of Environment, Forest and Climate Change (MoEF&CC) discussed the Sillahalla hydroelectric project with the Tamil Nadu officials in a meeting conducted over videoconferencing over the issuance of Terms of Reference (TOR) to the project proponent. The EAC took note of the representation by ecologists, scientists and the NGOs of Nilgiris. The EAC asked for further points to the TOR, including clearance from the National Board of Wildlife; study of the proposed project on the nearby wildlife sanctuary and include conservation plan/mitigation measures in the environment impact assessment and the environment management plan; and an assessment of an environmental cost-benefit analysis.

According to local resident Raju Gowder, most of the people to be affected by the project will be marginal farmers and agricultural workers with landholdings mostly around an acre. “We are groping in the dark about the proposed project which may cause large scale displacement other than severe losses in terms of livelihood and forest loss. The state government has not yet taken us in confidence and no information about the risks and dangers involved in the project have been made public so far,” he said.

“We have been knocking at every possible official door to know the number of farmers and the farm lands to be affected by the project. There is no clarity on the mode of compensation and the ways in which the government planning to ensure us alternative livelihood,” he said. Like in other parts of Nilgiris, majority of farmers in the proposed project site lack proper land ownership documents and as a result they may not be able to seek compensation legally.

According to A. Bhojan, a farmer from Kattadimattam village, over 150 families residing in the proposed project area are facing displacement. They are victims of the floods and landslides occurred in the last three years and yet to survive the impacts of the nature’s fury. Now the project is turning a double dose of misfortune.

“The whole area is identified as landslip-prone. Most of the farmers here are living here for generations and they eke out a living by struggling hard with adverse weather conditions. For them, the dam will destroy their livelihoods and cause large scale displacement,” he added.

When contacted, the district collector of the Nilgiris, J Innocent Divya, said that the implementation of the project would be undertaken only after the environmental impact study and consultations now approved by the union ministry. “The district administration will soon discuss with TANGEDCO, farmers and environmentalists about the modalities of the study and public hearings,” she said.

Read more: Nilgiris district collector says, environment before development


Banner image: Bembatty village where the upper reservoir of the Sillahalla hydroelectric project is expected to be located. Photo by Mathimaran.

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