Deforestation, urbanisation, illegal mining, waste dumping leave Cauvery battered and bruised

Decades of degradation has led to an unprecedented crisis for the 15 million who live on the banks of the river. Down To Earth travels along the course of one of India’s biggest rivers to understand why its level hit a record low this year

By Jitendra
Published: Tuesday 06 August 2019
Talakaveri, the origin of the Cauvery river, is way too still. Photo: Abhishek N. Chinnappa

Move on and live long, Oh Cauvery!” For some 15 million people living on the banks of this river and its 21 tributaries, the ode by Prince Ilango Adigal in the Tamil epic Silappadikaram is the mantra of life. More so, because barely a trickle now remains in the 805-km river that flows through Karnataka and Tamil Nadu.

There’s not more than knee-deep water in Talakaveri, the source of the river in Karnataka’s Kodagu district. Water here is so still that it has turned green with algae. It is mindboggling how this is possible in the Western Ghats, one of India’s highest rainfall zones.

Last year, the Cauvery basin received 4 per cent above normal rainfall. By August, all the dams were overflowing and soon both the states were drowning in floods. This year, the two states are reeling under a severe and unprecedented water crisis. In Kodagu, every lane is dotted with water tankers.

Water crisis forced schools to extend their summer vacation in Dakshina Kannada and Udupi districts of Karnataka. In a locality in Chennai, Tamil Nadu, residents complained that sewage water was flowing out of hand pumps, the only source of water in their area. The situation forced the Cauvery River Management Water Board to ask the Karnataka government to release water to Tamil Nadu.

Monsoon broke in Karnataka a week late, on June 8 this year. The drying riverbed hoped to be agush with water. The season has completed half its cycle, but registered 46 per cent deficit rainfall. A reprieve for the river seems unlikely.

“The river stagnates every year in May. This year, it stopped flowing in March itself. I have never seen such a miserable state of the Cauvery,” says 57-year-old Choomi Puvaya, a big farmer who owns 35 hectares (ha) in different parts of Khardigone village in Kodagu.

This year, the river’s water level hit a record low, shows data of the then Ministry of Water Resources, River Development and Ganga Rejuvenation. On June 13, it was 1.06 billion cubic metres (bcm), just 12.68 per cent of the river’s storage capacity.

Last year on this day, it was 1.90 bcm, which is 22.83 per cent of the river’s storage capacity. The Cauvery’s tributaries, Harangi and Lakshmantirtha, are absolutely dry. Other rivulets emanating from it are also drying up fast. Only a thin stream remains of the Iruppu Waterfall that once gushed down the Brahmagiri hills in Kodagu. Nagarhole and Keerehole lakes have simply disappeared.

Rainfall trends in the area show a sharp decline over the past few decades. Between 1956 and 2016, in Madikeri taluka, where the river originates, rainfall reduced by 8 mm per year. The situation has befuddled experts: why is rainfall in the Cauvery river basin inconsistent, causing floods as well as droughts?

Tourist resorts  have replaced natural paddy fields that recharge groundwater (Photographs: Vikas Choudhary/cse)

REASONS START UNFOLDING as Puvaya points at his 9 ha farm below the Kurubara Matte mountain range, just about 60 km downstream from Talakaveri. On one side are natural paddy fields. During monsoons, rainwater flows down the hills to the fields.

Puvaya has made arrangements to hold this water for four months during the kharif season, from July to November. When the crop is ready, he releases it to the many natural streams that fall into the Cauvery. Farmers here have been traditionally practising this method for centuries as it recharges groundwater and also acts as a natural feeder to the river.

But as paddy stopped giving returns, Puvaya decided to build a sprawling tourist resort on a large part of the natural paddy field, drastically changing the land use. A tarred road makes accessibility to the resort easy. He also grows silver oak, areca nut and oil palm trees that fetch him quick money. Silver oak is used as plywood, areca nut is grown for its fruit (supari) and palm for its oil.

The size of Puvaya’s paddy field has shrunk from 9 ha to 4 ha, while plantations and concretisation have increased. Puvaya no longer needs the huge amount of water he once required to irrigate his paddy field. When it rains, he lets the water flow down directly to the natural streams. Result: in November-December when the river is water-starved, it barely gets any water from the paddy fields. And when it is bulging during monsoons, the river gets huge amounts of water, creating floods.

Puvaya earns ample profits from the resort and the plantations, but he realises that he has added to the environmental problem. “People planted new species of trees replacing the traditional jackfruit, rosewood, nandi and hone trees, and all varieties of bamboo. These are endemic to the area. They have thick and deep roots, and hold water underground,” says Roy Bopanna, an environment activist.

Between 2013-14 and 2017-18, land area under areca nut in Karnataka increased by 61,000 ha, and the total acreage in the state reached 0.28 million ha. In Kodagu alone, oil palm is being cultivated in over 1,100 ha. These trees cannot hold water, but grow fast and bring good money.

THE STORY OF the water crisis in the Cauvery’s basin was scripted decades ago. In the 1980s, people cut down traditional trees and replaced them with coffee plantations.

As land here is ideal for its growth, coffee proved to be a huge success. From 2007 to 2017, land under coffee plantation increased by 4,000 ha in Kodagu. Now, Kodagu has 43 per cent of India’s coffee plantations, and 80 per cent of India’s total coffee comes from Karnataka. Kerala, too, is growing coffee over 86,000 ha and boosting its economy.

“But coffee plants cannot hold water or soil as they have small roots. They neither conserve nor restore rainwater,” says S Janakarajan, former professor at Madras Institute of Development Studies, Chennai.

Growing coffee excessively on steep slopes that have loose soil and are heavy with water result in landslides, says Bopanna. Small wonder, Kodagu witnessed a land-slide last year, destroying coffee plantations, nearby houses, and also choking river streams. Now even a year later, the area has not recovered from a water crisis.

Excessive plantation of coffee reduced groundwater levels, and soon the area witnessed a sharp rise in the number of borewells. “About 15 years ago, there were less than 20 borewells within 5 km radius. Now, the number has risen to 100 plus,” says Sreenivas Reddy, director, Karnataka State Natural Disaster Monitoring Centre.

Coffee Agroforestry Network, an international project funded by the European Union to study the loss of diversity, directly links the drop in forest cover to changes in the coffee-growing system which shifted from streamfed shady plantations to irrigated plantations. In Kodagu, forest cover decreased by 28 per cent between 1977 and 1997.

Data with Global Forest Watch, which does real-time monitoring of forests, shows that in the past 17 years, the Western Ghats, one of the world’s top eight biodiversity hotspots, lost 20,000 ha of tree cover in four Karnataka districts—Uttar Kannada, Dakshin Kannada, Udupi and Kodagu. In 2015, about 50,000 trees were cut in Kodagu to set up electricity lines for industries. Another 300,000 trees are going to be cut to widen national highways 4A, 75 and 13, and for a railway project to connect Kodagu with Mysuru.

Also, the new coffee plantations have blocked the forest corridor which elephants used earlier. At one point in the Virajpet taluka near Kerala’s Wayanad district, coffee planters have spared only 2-3 metres for elephants. The Cauvery touches Kerala at Wayanad in the form of Kabini, the river’s tributary, and flows till Mysuru.

“How will a herd cross the thin bypass without destroying the plantations?” asks Colonel Mutthana, president of Coorg Wildlife Society. In the past few years, incidences of human conflict with wild boars, porcupines, anteaters, leopards, elephants, monkeys and peacocks have increased, says Puvaya.

But the government, it seems, is not bothered that land use changes have deeply impacted the environment, and thus people’s lives. “Government documents categorise coffee estates and the new trees as forest area, so according to them there has been no loss of green cover,” says Mutthana.

Moreover, at least 2 million tourists visit Kodagu every year, in addition to half a million residents. “Big resorts like Tamra, Taj Vivanta and Club Mahindra have come up which either block or divert the perennial streams for their own use,” says Bopanna.

“Club Mahindra extracts 0.25 million litres of water every day from Koothole dam, the main source of drinking water for at least 12 surrounding villages. The resort also has a huge private reservoir,” he adds. 

Mindless growth of coffee plantations caused landslide in Kodagu, Karnataka

“The waste the district generates goes directly into the Cauvery, the sludge further restricting the flow. Almost 0.5 million litres of untreated waste water and human faeces is dumped in the Cauvery in Kodagu itself,” says MN Chandramohan, convener of Kaveri Nadi Samrakshaka Sangha, a non-profit working to clean the river.

Reports of Karnataka State Pollution Control Board and Tamil Nadu State Pollution Control Board show that the total dissolved solid (TDS) level in water increases as the river flows downstream. The TDS level in Madikeri is 57 mg per litre, 67 in Kushalnagar, 201 as it reaches Mysuru, and 301-487 at Mekedatu Sangama. As per WHO guidelines, TDS level of potable water should be below 300 mg per litre.

AT KUSHALNAGAR, NEAR Mysuru, the Cauvery is bone dry. Illegal sandminers work fearlessly on the riverbed, digging beyond permissible levels severely depleting the water table. “The permissible mining limit is 1 metre, but illegal miners excavate the riverbeds up to 6 metres creating huge pits,” says Chandramohan. 

Indiscriminate mining has adversely impacted acquatic life. The river had 148 species of fish, of which 17 are endemic to the river, shows Biodiversity Board of Karnataka data.

This is the highest in the country. But many species have either disappeared or are under threat of extinction. The hump-backed mahseer, once a common Cauvery fish, has now been categorised critically endangered by the International Union for Conservation of Nature. Red-tipped halfbeak, slender stone loach, mrigal carp, Wayanad mahseer, Korhi barb, Nilgiri barb, Nilgiri mystus, Bhavani barb and Cauvery barb are all facing the risk of extinction. 

The river recovers its water at Mandya, the last Karnataka district it flows through. But it also faces the onslaught of industrial pollution here. The Krishna Raja Sagara Dam, also called KRS Dam, minimises its pace, as it moves towards the Bay of Bengal.

THE CAUVERY ENTERS Tamil Nadu at the semiarid Dharmapuri district, and for the first time it flows freely. As the river dives 20 metres, it creates the Hogenakkal Falls. But its freedom is short-lived. Stanley, the largest dam in Mettur, again restricts its momentum.

Mettur, a small town in Salem district, dumps untreated effluent from tannery, paper and textile units, increasing toxicity. And by the time it reaches Erode district, the Cauvery is nothing but a sewer. “A landfill on the dry riverbed gets submerged during the monsoon, converting the river into a waste stream,” says Adhavan Ashokan, a resident who works in a textile firm. 

Pollution levels here are the highest in the country, shows a government-funded study conducted in December 2017 by the Anna University in Tamil Nadu. In Mettur and Erode, TDS level is an astounding 1,750 and 1,450 mg per litre. The average TDS level in the Cauvery is 753 mg per litre. 

There is hardly any water at Salem district as the Stanley reservoir upstream restricts the Cauvery’s momentum (Photograph: Vikas Choudhary)

“Toxic water has made many women of the region infertile, so people don’t marry women from in and around Erode and Karur,” says Thambaya Sitaramani, a farmer who is also the coordinator of Kaveri Surplus Water Action Committee in Salem.

“Salem takes the industry’s filth, Erode takes the garbage from Salem, while Trichy accepts Erode’s filth. Till the Bay of Bengal, the journey is not that of the river, but that of filth,” says Peeyush Manush of Salem Citizen Forum who is working to rejuvenate the waterbodies in Salem district. 

As the Cauvery enters the plains of Tamil Nadu, it widens and forms a delta. Large-scale groundwater extraction for farming and sand mining have sealed the river’s fate.

“Every day, illegal miners dig the riverbed and supply 10,000 lorries of sand to the construction industry,” says Vetriselvam Muthuraj, a Chennai-based lawyer. “Sand mining erodes river’s banks and the bottom, while also damaging the bedrock which is responsible for self-distillation,” says Janakarajan. 

The basin is already starved of sediments. As many as 96 dams, 10 barrages and 16 anicuts, besides 54 irrigation projects and 15 major hydroelectric projects upstream, have blocked silt from flowing downstream.

Silt helps create delta at an elevation, which differentiates riverwater from that of the sea. But absence of enough silt has shrunk the Cauvery’s mouth. Now, the river’s flow has reversed: instead of the river water flowing into the sea, the Bay of Bengal has entered 17 km into the delta and turned the water saline.

(This article was first published in Down To Earth's print edition dated August 1-15, 2019)

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