How the Mekedatu dam project in Cauvery valley endangers four threatened species

The ramifications of flooding one of the last remaining strongholds of four threatened species cannot be compared with the economics of a mega project.
The endangered grizzled giant squirrel
The endangered grizzled giant squirrel

Very often, an imagined view of ‘wild spaces’ is symbolised as the vast savannahs of Africa, rainforests of Amazon, snow laden tundra of Siberia or the immense iciness of Antarctica. In India, it is difficult to visualise stretches of wildlands shared by humans and wildlife. However, barely 100 km from the urban sprawl of Bengaluru lies a remnant of India’s ancient wildlands, a wind-swept landscape where wildlife still abounds, and forest laden hills stretch as far as the eyes can see.

This is the isolated Cauvery valley, the last stretch of the free-flowing mystic river in Karnataka where the arboreal grizzled giant squirrels still screech from the forest canopy, herds of elephants cross the river as crocodiles bask in the distance, otters frolic on the sand banks and fish eagles perch high above. You may see a sloth bear foraging for food beneath boulders or a porcupine hurrying to take shelter in the thickets. If you look hard enough, you may chance upon a leopard vanishing behind the shadow of the hills as scores of spotted deer and four-horned antelopes stand alert in their stiff posture – the Cauvery valley is a veritable paradise.

At the valley, you experience a sudden drop of altitude as you enter a seemingly surreal world where the steep landscape changes into an arid shrub land and then into a bustling forest. Villages are left behind and you would be excused for forgetting that you are a mere couple of hours away from the madness of the city. With a predominantly dry climate – albeit rich with water from the Cauvery, the Palar and several streams – the river system is unique in this stretch of the Cauvery. This setting imparts much-needed life into the river systems and unleashes a wealth of diversity with profuse fish populations and an abundance of other life forms. In lieu of its isolated nature, the Cauvery Wildlife Sanctuary was instituted in the year 1987 providing safe passage to the Cauvery river meandering through it.

Cauvery river flowing through the wildlife sanctuary | Pic by Sivaprasad
However, the past few decades have seen an increasing clamour to divert water from rivers and prevent it from flowing into the sea. Using this logic, it is proposed to again dam the Cauvery river, which provides Bengaluru about 1,350 million litres of water per day, and permanently alter this ancient landscape. Government analysis estimates that Bengaluru will require 2,285 million litres of water per day by the year 2030, which can be met if the 67 tmc capacity Mekedatu dam project is implemented successfully. More than 50 square km of land will be submerged as a result of a balancing reservoir in the proposed Mekedatu project. Tellingly, only six villages are scheduled to be flooded while the remaining area is mostly forested.

Four threatened species at peril

A dam can serve the purpose of substantially augmenting the needs of a water stressed city. However, the issue here is that the proposed land for the submergence zone happens to be an Eden for life forms. An international icon, the valley is home to not one but several threatened species, some of which are rapidly vanishing across most of their natural habitat. Straining our neck at the impossibly tall Terminalia arjuna trees that dot the riverbanks, looking for the elusive grizzled giant squirrel, one is aware of standing a few feet away from the natural habitat of the river-dwelling mahseer on one side and the four-horned antelope on the other. These four threatened species thrive in the Cauvery valley and the ramifications of flooding one of their last remaining strongholds cannot be compared with the economics of constructing a mega project.

Cauvery valley with the river flowing through it | Pic by Abhijit Dutta
Of all the four species, the threatened grizzled giant squirrel counts the valley as one of its last habitats in their northernmost range. The arboreal squirrel seldom comes down to the ground and is found only in few forest patches of Kerala, Tamil Nadu and Karnataka. In Karnataka, it can only be found on the Cauvery banks in the Cauvery Wildlife Sanctuary. This riverine species needs the giant arjuna, tamarind and jamun trees that thrive in the Cauvery valley, and with the valley expected to be fully submerged as a result of the proposed Mekedatu dam, the bells of extinction will toll for the squirrels in one of their last remaining homes.

Grizzled giant squirrel | Pic by Joshua Barton
The critically endangered hump-backed mahseer is a creature of fast flowing rivers and thrives in wild country and deep gorges. The salubrious Mysore plateau has some of the best-preserved stretches of the fish and the region from Shivasamudram to Mekedatu is known to house giant mahseers. The mahseer found in this stretch of the river is already highly threatened due to pollution, poaching and reduction of its natural habitat. Can the species survive another dam in its last home?

Mahseer | Pic by Joshua Barton
Of the six antelopes found in India, four are found in Karnataka and of those, the vulnerable four-horned antelope competes with other species as the most charismatic of the Cauvery landscape. This small antelope is probably the only antelope in the world with four horns and is generally found in the highlands of the Cauvery valley with occasional visits to the riverbank. Known to leap in fast-motioned sprints upon sensing human presence, the antelope forms an important prey base for carnivores in the sanctuary.

Giant Terminalia arjuna trees can be spotted across the banks of the Cauvery river. Generally found near streams and rivers, rural folk in some parts of India believe that this magnificent tree is an indicator of water in the forest. The arjuna trees along the Cauvery are iconic as they are huge in size with several known to be over 100 years old. They form important nesting sites for numerous bird species found here, with birds even living inside the trunk of these trees. Several raptors use these trees as perching sites to locate their prey. The proposed dam will certainly drown the trees and wash away their ancient legacy.

Cauvery river | Pic by Sivaprasad
Bengaluru, which is blessed to have a biodiverse forest near it, may soon be the reason for the forest’s destruction, risking the very survival of riverine species. The human cost of relocation may be relatively minor. But the existential fate of the grizzled giant squirrels and the mahseer cannot be compared to that of the project, which currently stands at Rs 9,000 crore, as the real economic value of the riverine forests is infinitely more. The project envisages lifting and transporting the water for more than 100 km, all the way to Bengaluru. While the need of the urban dweller may be urgent, fulfilling it at the cost of sinking this wildlife sanctuary and not searching for sustainable solutions is a recipe for disaster.

But there is still some hope. The onus is on Bengaluru citizens to make the administrators accountable for harvesting existing sources of water. A city formed by tapping into age-old rainwater harvesting and tank-based irrigation can still spare the Cauvery valley by making the right choices. And while we debate, the grizzled giant squirrels play in their usual manner, jumping from one tree to another, screeching with joy, unaware of what may come next. The Bengalurean needs to take a call on whether he wants to hear a joyful racket from these forests in the future or just the last staccato cackle of the endangered squirrel.

Abhijit Dutta works in the field of conservation and Kunal Sharma is a faculty at Azim Premji University, Bengaluru. Views expressed are the authors’ own.

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