CHENNAI: “What if Karnataka does not release Cauvery water? People used to say Noyyal, Bhavani and Amaravathi will sustain it,” said V Jeevanatham, from Tamil Nadu Green Movement, recalling the times he swam in the Noyyal river as a child. All three rivers run almost dry and are victims to unsustainable growth models. The tributaries that spring in the State and its borders once flooded their way to embrace the main stream.
Over the years, the courses of the mighty Cauvery and its tributaries have dwindled drastically. While Tamil Nadu points fingers at Karnataka for the shortage of water, the State has failed to maintain and care for local tributaries that fall within its own boundaries.
In fact, Tamil Nadu on Wednesday filed a new plea in Supreme Court, stating that Karnataka had not released the fair share of water they agreed to supply. The State alleged that Karnataka was obligated to give 22.5 TMC water in 25 days, while only 16.58 TMC was given.
Tamil Nadu has, however, failed to look inward; a mistake that Karnataka too is doing. Tributaries, rivulets, canals, aquifers and rain-fed tanks that converge to form Cauvery are either dying or dead. This has pushed the State to rely completely on the external flow of water alone.
Conversations with local residents and activists point out that the reasons for the receding flow of water in three major Cauvery tributaries — Noyyal, Bhavani and Amaravathi — are similar.
The river that originates at Vellingiri Hills in Western Ghats springs from seven major tributaries in foothills of Nilgiris. Before it joins Cauvery at Kodumudi at Erode district, it travels through Coimbatore, Tiruppur and Karur. At every step of the journey, Noyyal gets a little more degraded.
Noyyal, like most rivers, emerges from hilly forests. Thin streams of water converge to form rivulets and tributaries subsequently building Noyyal.
“During years of scanty rainfalls, some of these rivulets dry up leaving empty spaces. If they are dry for few years at a stretch, resorts are quickly built in the hills in those spots cut off the potential for regeneration of these streams,” says Jeevanantham, adding that several streams contributing to Noyyal have vanished over the years.
“Deforestation and urbanisation in hilly areas have led to the lowering of water-retention ability in the mountains,” he said. Urbanisation of cities too has cut off efficient draining of storm water into the rivers, corrupting the relationship between tanks and the river.
Urbanisation is tailed closely by industrialisation. Industries all along the river hamper it severely. Bottling units dot either side of the river till it reaches urban areas. Leading bottling companies use borewells to suck water and package it. A local activist and writer, M Siva, said that several of these plants are illegal. “Bottling companies that use borewells that are 700 ft deep pulls the groundwater table down to that level in all nearby areas,” says Siva, adding that the amount of water drawn by industries from borewells is not measured.
Reports by several researchers suggest that levels of both groundwater and surface water have effectively gone down over the years. It is still unclear if the river recharges the tanks or if it is the other way round, suggests ‘Water Management in the Noyyal River Basin’, a report by the Ashoka Trust for Research and Ecology and Environment (ATREE). “Whether Noyyal discharges into the groundwater table or is recharged by the local groundwater or both, in different sections, remains unclear,” the report says.
While several obstacles curb entry of water into the river, the little that makes it gets polluted.
Stream water that is clear at the origin shows first signs of pollution as it approaches Coimbatore. The Noyyal sub-basin is highly urbanised with a population of over 42 lakh, according to the census of India 2011. More than three-fourth of this population resides in urban settlements and a quarter in 243 villages. Coimbatore and Tiruppur are among the most populated.
As Noyyal flows through Coimbatore, it collects the city’s sewage and Siva accuses the Coimbatore Corporation for causing that pollution. “Major hospitals and large buildings in the city release their untreated sewage into the river. They do so by directly letting it into the underground sewage,” says Siva.
The river then flows into Tiruppur, an industrial town known for garment manufacture and export.
For decades, factories have dumped their industrial effluents into the river. The Supreme Court in 1996, decided to intervene and ordered the dyeing units at Tiruppur to not pollute. The industrialists, however, continued to do so. In a follow-up, the Madras High Court implemented a rule in 2011 that directed industries to have zero discharge of water. That is, industries were expected to treat and recycle all water to be used by the industry again.
While most large units have set up treatment plants officially, smaller ones have chosen to set up Common Effluent Treatment Plants (CETPs). Siva alleges that the monitoring of these industries continues to be poor.
“The river water has been rendered useless by the industrial Tiruppur,” he says.
The dark, polluted water drifts from there and trickles out of Orathupalayam dam, one of the most polluted reservoirs in Tamil Nadu. Between 2001 and 2005 the dam was even shut responding to farmers’ fear that the water may cause permanent damage to their crops and health.
Following heavy rain in 2005, the floodgates were opened, leading to a toxic disaster. Water contaminated by four years of pollution flushed out of the dam, killing hundreds of tonnes of fish. The reservoir has remained open since. A constant weak flow of contaminated water leaks from the dam, leaving the construction redundant. From there, it slowly makes its way to Cauvery or does not in drought-hit years.
Born from 12 tributaries, Bhavani also originates at the Western Ghats. The river that runs for over 200 km snakes first into Kerala, where it is intercepted by 6 dams, before entering Tamil Nadu.
Bhavani’s tale is similar her sister Noyyal. The quantum of water that flows at the source too is tapering for the identical reasons — depletion of forest and natural habitat in the western catchment area. While sewage from urban settlements of Coonoor, Mettupalayam and smaller towns pollutes the river, large industries seated at Thekkampatti add to the toxicity of the river.
According to a report by Tamil Nadu Water Supply and Drainage Board (TWAD), Bhavani water, which is supplied to 1.5 lakh residents of Mettupalayam for drinking purposes, is unfit for consumption as it is turbid with iron values exceeding safe limits. The water was also declared bacteriologically unsafe due to the presence of faecal coliform, the source of which is human and animal excreta.
Untreated water discharged to it by industrial units and the 28 canals carrying sewage water from the municipality are blamed as sources for this pollution.
“Ophthalmic acid, formaldehyde and harmful heavy metals such as arsenic, lead and iron contaminate the water,” says Dr N Maheshwaran, adding that skin-related disorders are on the rise in the Bhavani basin. “These chemicals cause skin dermatitis and even skin carcinoma, a type of cancer in some,” he remarked.
Dr Maheshwaran, who runs obstetrics, gynaecology and paediatric clinic in Mettupalayam, adds that the number of infertile patients he has been receiving is on the rise. The reduced base flow of the river has also led to stagnation of water and an increase in mosquito-borne diseases such as dengue.
Maheshwaran takes a special interest in the health of Bhavani and is working on a documentary on the river’s condition. “Though Companies such as ITC Paper Mill, Sharadha Terry and United Bleacher’s Ltd claim to treat their effluents, we do not see an increase in the quality of water,” he says, adding that thousands of dead fish are found in the river on many days. Earlier in June, thousands of dead fish were found on the banks of Bhavani and in private wells. “For aquatic organisms to die, on such a scale particularly, the Total Dissolved Solids (TDS) levels in water must be over 1,000 mg per litre. Whereas TNPCB’s sampling revealed values less than 200 mg per litre,” Maheshwaran alleges.
The story of Amaravathi is not very deviant from that of Noyyal and Bhavani. About 500 industries sit at Karur, on the banks of Cauvery’s longest tributary. The problems that affect Amaravathi and other tributaries are only geographically different. Amaravathi carries the sewage of Karur municipality and the industrial waste of leather tanneries, and also the consequence of unsustainable growth that other rivers face.
While the release of Cauvery water from Karnataka plays a crucial role in increasing base flow, understanding the story of the tributaries within the State suggest that water management of rivers is a crisis comparable to the scarcity of rainfall and external supply.