Since the earliest of times, through the most ancient civilisations, rivers have always been lifelines to humankind. Both revered and feared at times, all cultures and religions have accorded rivers significance.

River Cauvery is no exception. Passions run high in the southern states of India when the subject of debate is the river. Though venerated at its source at the Talakaveri in the Brahmagiri Hills, River Cauvery has been heavily exploited throughout its running length, except for perhaps the 100-odd kilometres that flows through the Cauvery Wildlife Sanctuary (WLS). Or so we thought until the proposal for the Mekedatu Project.

River Cauvery flowing through the Cauvery Wildlife Sanctuary in Karnataka
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Originating in the wet, evergreen forests of the Western Ghats, at the venerated Talakaveri in the Brahmagiri Hills, the Cauvery flows eastwards, making her way through coffee estates, rice fields and small stretches of forests. Photograph: Mansi Anil Kumar

About 90km from Bangalore, Mekedatu is where the Cauvery river plunges into a deep gorge and gives life to a complex riverine forest. The word mekedatu in Kannada means “goat’s leap”. The name comes from an old folktale about a goat that leapt across the gorge to escape a tiger. Not just any goat, but a divine one—it was the Hindu god Lord Shiva in disguise. The rocks here are dotted with inexplicable holes that look like goat hooves, albeit much larger. So large that they could only be attributed to an ungulate that was a god in disguise. Mekedatu connects the Biligiri Ranganathaswamy Temple (BRT) Tiger Reserve and the Male Mahadeshwara Hills (MM Hills) wildlife division, an emerging tiger reserve.

River Cauvery flowing through Mekedatu in Karnataka
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Mekedatu is where the Cauvery river plunges into a deep gorge and gives life to a complex riverine forest. Photograph: Mansi Anil Kumar

The Cauvery WLS is home to several endemic and endangered species of flora and fauna. Tigers, otters, elephants, honey badgers, Sloth Bears, Four-horned Antelope, gaur, and reptiles like the Mugger Crocodile and Indian Flapshell Turtle still depend on this river as they have through millennia.

Smooth-coated Otter with fish on the banks of River Cauvery
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Smooth-coated Otter (Lutrogale perspicillata) | Photograph: Philip Ross
A pair of Indian Scops Owls perched on a tree
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Indian Scops Owl (Otus bakkamoena) | Photograph: Mansi Anil Kumar
Golden Jackal with a Spotted Deer kill
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Golden Jackal (Canis aureus) with its kill, a Spotted Deer (Axis axis) fawn. Photograph: Philip Ross
Brown Hawk-Owl perched on a tree
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Brown Hawk-Owl (Ninox scutulata) | Photograph: Mansi Anil Kumar

Of all the threatened flora and fauna in the region, four species stand out the most: the tall Arjuna tree, Grizzled Giant Squirrel, the river-dwelling Hump-backed or Orange-finned Mahseer and the Four-horned Antelope.

The Grizzled Giant Squirrel (Ratufa macroura)

The Grizzled Giant Squirrel seeks a riparian habitat and is found in a few forests in Kerala, Tamil Nadu and Karnataka. They hardly ever grace the forest floor, and you have to spy them out through the tall Arjuna, tamarind and jamun trees. The species is listed as Near Threatened on the IUCN Red List. The Grizzled Giant Squirrel weighs between 1.5 to 3kg and has a body length of 25-45cm, with an equally long or slightly longer tail.

Compared to the squirrels we see around our neighbourhood, small enough to be aptly called the Indian Palm Squirrel—weighing only around 150gm and measuring 23 to 35cm in length, including the tail—the Ratufa macroura is truly a giant. The Grizzled Giant Squirrel is one of the four giant squirrel species found worldwide. India is also home to the Malayan Giant Squirrel, which is found in north-eastern India, and the Indian Giant Squirrel or Malabar Giant Squirrel, commonly seen across the forests of the Western Ghats.

Endangered Grizzled Giant Squirrel in Cauvery Wildlife Sanctuary
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"The Grizzled Giant Squirrel weighs between 1.5 to 3kg and has a body length of 25-45cm, with an equally long or slightly longer tail." Photograph: Mansi Anil Kumar

The Grizzled Giant Squirrel has an appetite of a growing adolescent and loves to feed on tamarind, mango, and leaves and bark of trees. Though shy creatures, they make for responsible parents. Like how in a convoy of cars one never knows which houses the premier of the state, the mother squirrel creates multiple nests to fool the Crested Hawk-Eagle, Shikra and Brahminy Kite. Sadly, with the disappearing forest cover, giant squirrel populations are also in decline. Of the ~500 Grizzled Giant Squirrels left in India, ~50 call the Cauvery WLS home.

The Hump-backed Mahseer (Tor remadevii)

The region from Shivasamudram to Mekedatu is home to the Hump-backed Mahseer, a species of fish from the family Cyprinidae. These alluring orange-finned fish thrive in the swiftly flowing waters of the deep gorges of Cauvery WLS. Their near-perfect ecosystem comprises riverbanks dotted with fruiting trees and a riverbed with shifting sand at the bottom and strewn with rocks that break the water flow. The Hump-backed Mahseer rose to fame way back in 1870 when G.P. Sanderson, a British naturalist from Mysore, caught a massive fish in the Kabini River, weighing about 60kg—almost the weight of a “fully grown man”, as he noted in his diary.

Over the years, anglers have travelled from far and wide to try their luck with the Hump-backed Mahseer they fondly call the “Tiger of the Cauvery.” Their fierce nature, orange fins and status as the brand ambassador for river conservation in the region have earned them this moniker. Studies from Bhutan show that (related) mahseers can migrate over 100km during the monsoon season. They have a strong homing instinct, and year on year, they return to the main river after spawning in specific shallow waters closer to the source.

Angler with a large Hump-backed Mahseer Tor remadevii in Cauvery Wildlife Sanctuary
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An adult Hump-backed Mahseer (Tor remadevii) captured by Martin Clark in 1978, at the Cauvery WLS. Photograph courtesy of Trans World Fishing Team/Pinder et. al, via Wikimedia Commons under the CC BY-SA 4.0 license

According to conservation biologist Naren Sreenivasan, who works with the Wildlife Association of South India (WASI), the Hump-backed Mahseer cannot survive in a homogeneous habitat like a lake or a fragmented river—they will live but will be unable to breed successfully. “The humpback eats the seasonal wild mangoes or riverine jamuns that fall into the water from the trees along the banks, whereas in fast waters where fruiting trees are fewer, they tend to feed more on smaller fish, crabs, and molluscs,” says Sreenivasan. The local hump-back population around Srirangapatna and Kabini went extinct once the Krishna Raj Sagar Dam and Kabini Reservoir were built.

The Four-horned Antelope (Tetracerus quadricornis)

Of the six species of antelopes native to India, four of them are found in Karnataka. Among those, the Four-horned Antelope or Chousingha is as enticing and elusive as perhaps the golden deer that Maricha disguised himself as to lure Lord Rama away from his wife Sita in the Hindu epic Ramayana. Chousingha is the only antelope in the world with four horns and forms a crucial part of the food chain within the Cauvery ecosystem. Thriving in dry deciduous forests and shrublands, the Chousingha is listed as Vulnerable on the IUCN Red List.

Four horned antelope or Chousingha in Cauvery Wildlife Sanctuary
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The rare and elusive Four-horned Antelope (Tetracerus quadricornis) is the only antelope in the world with four horns. Photograph: Philip Ross

The Arjuna Tree (Terminalia arjuna)

The bare buttress roots of the Arjuna trees are akin to the hard-earned muscles of a bodybuilder in a gym. I wonder if that is why the tree was named after the renowned archer, Arjun of the Pandavas, from the Hindu epic Mahabarata. The buttress roots help these trees to establish a firm grip on the eyots or river islands. Consequentially, the soil resting under the shadow of their large canopies is moist and rich in organic carbon.

Putting gravity-defying manmade structures to shame, the branches of black plum, tamarind and fig trees interlock with those of the Arjuna trees, and their weave and waft create an uninterrupted arboreal bridge that runs for many kilometres. Sheltered by its rich canopy and cradled in its network of roots, there is an entire community of plants that thrives beneath.

large buttress and roots of Arjuna Tree Terminalia arjuna on the banks of River Cauvery
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The buttress roots of the Arjuna tree (Terminalia arjuna) help it establish a firm grip on the eyots or river islands. Photograph: Mansi Anil Kumar

The Proposal to Wipe Out An Entire Forest

The Mekedatu Project is a proposed gravity dam with a planned capacity of 67.16TMC (thousand million cubic feet) and can generate 400MW of electricity. The proposed site is near the confluence of the Arkavathy and Cauvery streams at a place called Sangama, which resides within the sanctuary. The construction will inundate approximately of forest cover. While we still find check dams across the Cauvery river, which help irrigate adjacent lands, they are not as damaging as hydroelectric projects. The Mekedatu Project will have a devastating impact on species like the critically endangered Orange-finned Mahseer and the endemic Grizzled Giant Squirrel.

Proposed site of the Mekedatu Sangama dam project
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Dam markings painted on the rocks at the proposed site of Sangama, within the Cauvery WLS. Photograph: Mansi Anil Kumar

The Karnataka government is building the dam to fulfil Bangalore’s burgeoning water demands. The capital city’s water shortage has been hastened by the unprecedented levels of urbanisation and depletion of water resources. The Karnataka government staunchly believes that only the proposed Mekedatu Balancing Reservoir Project can bail out the city from the present crisis. However, it is very evident that the dam construction will destroy a unique and beautiful wilderness. Environmentalists and conservationists have been striving tirelessly to raise awareness, mobilise public opinion and ensure international interest in protecting what remains of this green corridor. The neighbouring state of Tamil Nadu fears that the project would further reduce its already dwindling share of Cauvery water, which is crucial for paddy cultivation in the Thanjavur-Nagapattinam-Trichy delta region.

Mugger or Marsh Crocodile in River Cauvery
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The riverine biodiversity are the first victims of projects such as the Mekedatu Balancing Reservoir. Mugger Crocodile (Crocodylus palustris). Photograph: Mansi Anil Kumar

Earlier this year, an all-party delegation from Tamil Nadu moved the Supreme Court seeking judicial orders to restrain Karnataka, stating that construction should not happen at Mekedatu without the approval of the lower riparian states. The Centre’s stance seems to be supportive of the need for alignment from the riparian states and clearance from the Cauvery Water Management Authority (CWMA). The Centre is also looking at appointing a neutral, full-time Chairman for CWMA—someone not from one of the states that have a vested interest in the outcome. A 15-member expert appraisal committee that reviewed the project had advised the state government to abandon the project and look for alternatives given the costs to the environment. Though, the report is yet to be made public.

River Cauvery flowing through Cauvery Wildlife Sanctuary in Karnataka
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" appears that in the absence of substantial mobilisation of citizen opinion and social activism, the Mekedatu Project cannot be successfully negated." Photograph: Mansi Anil Kumar

In recent weeks, the dam debate has once again reared its head with politicians like D K Shivakumar (Member of Karnataka Legislative Assembly) and Siddaramaiah (Leader of the Opposition, Karnataka Legislative Assembly) trying to pressurise the government to start work on the dam. Therefore, it appears that in the absence of substantial mobilisation of citizen opinion and social activism, the Mekedatu Project cannot be successfully negated.

The general public needs to take a joint stand to protect the Cauvery valley and its wind-swept landscape, where wildlife still abounds and forest-laden hills stretch as far as the eyes can see.