Living rivers, dying rivers: Rivers of Tamil Nadu and Kerala

The seventh lecture in the series titled "Living rivers, dying rivers" was on the 'Rivers of Tamil Nadu and Kerala' by S Janakarajan and A Latha.
28 Jun 2012
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Cooum river, Tamil Nadu (Source: Wikipedia)
Cooum river, Tamil Nadu (Source: Wikipedia)


This series coordinated by Prof. Ramaswamy R Iyer aims at understanding what has been happening to rivers across India and in drawing appropriate lessons. The lecture held on December 7, 2011 at the India International Centre, New Delhi highlighted the expanding ‘footprint’ of cities like Chennai anxious to secure new water supplies leading to competition for scarce resources. The problem of water pollution as well as the fallout of excessive groundwater use for agriculture in Tamil Nadu was discussed. Problems such as catchment deforestation, habitat fragmentation, dams and diversions, sand mining, incorrect land use, pollution and encroachments into rivers, contributing to dying rivers in the Western Ghats of Kerala were dealt with.


'In search of a living river: Let us traverse through Tamil Nadu

The presentation began with a brief introduction on how rivers in India have carried its political, economic and social history. Today water resources in the country are under great threat due to indiscriminate use, scarcity and pollution. This not only undermines the resource base but poses a severe threat to the very foundations of our society, culture and community’s sustenance. This is the context in which the speaker discussed the dying or dead rivers of Tamil Nadu:

  • Water pollution

The problem of water pollution poses a great threat to basic human living. The ramification of pollution is indeed more severe in the less developed countries that are afflicted with chronic problems of political instability, lack of political will, high level of illiteracy, unceasing poverty, increasing urbanization, rapid industrialization, high illiteracy and low level of awareness, women subordination, corruption, poor health care and poor social security system, high population density with poor rural and urban infrastructure.

Most importantly, there is the looming climate change threat and its impact on water resources, agriculture and food security. The growing menace of river pollution needs to be addressed in this context.

  • Invisible data

A major point raised by the speaker was regarding the problems with existing approach of data collection and dissemination. Information on visible data is collected very selectively - such as all land details, rainfall, crop details, water (surface and groundwater), income and consumer expenditure, assets and liabilities, livestock etc.

There are certain data which are never given importance such as on pollution of river basins, pollution levels of surface and groundwater, solid waste, bio-medical waste, urban sewage, e-waste generation and floods and droughts (socio-economic losses and expenses incurred by way mitigation). Can we neglect the invisible data?

  • Palar basin

Janakarajan discussed how pollution, excessive groundwater exploitation and increased competition over scarce water supplies have led to a crisis in the Palar basin. It is considered the second rice bowl of the state next to Thanjavur, irrigated by a complex network of tanks and wells. Now both the rice bowls have been disfigured.

The basin is highly urbanized with a flourishing rural-urban water market. Industrial activities like tanning and dyeing has grown rapidly and become a cornerstone of the basin’s economy. The basin has a very high concentration of tanneries and 75 per cent of the tanneries in the state are concentrated in this basin. These tanneries contribute to 30 per cent of the total leather exports of the country, earning Rs. 50 billion towards foreign exchange. Tanneries are highly water intensive and polluting industries, generating about 38 mld of effluent with high total dissolved solids, chromium and some traces of cyanide.  

Agriculture in the basin is very badly affected and is marked by decreased yield, abandoned wells, polluted surface and groundwater, acute drinking water problems and serious health problems. There has been a rapid decrease in agricultural employment and thousands of people have already left their villages.

Janakarajan shared the extent of pollutants generation in two major tannery centers of the Palar basin - Ranipet and Vaniyambadi. He stated that the yield of paddy was 628 kg/ha in the affected villages and  7118 kg/ha in the unaffected villages of the Palar basin (figures for 1999).

There has been a comprehensive failure of Common Effluent Treatment Plants (CETPs). The role of Tamil Nadu Pollution Control Board (TNPCB) has been marked by lack of effective monitoring and law enforcement mechanism. As regards mitigation and regulatory measures in the basin Janakarajan suggested public interest litigation and Supreme Court’s intervention through what is regarded as a historic judgment.

The Palar river has got the rare distinction of earning the third place among the ten most polluted rivers in the World identified by the Blacksmith Institute of New York in 1996. The criteria used for such identification were – (i) the size of the affected population (over 3.5 million) (ii) severity of the toxin(s) involved (iii) impact of children’s health and development (iv) evidence of a clear pathway of contamination and (v) existing and reliable evidence of health impact.

Janakarajan also discussed about the river inter-state river Cauvery. It is mainstay of Tamil Nadu and regarded as its granary. The main river takes the entire load from industries and urban waste and takes further load as it travels further down.

Noyyal: A tributary of Cauvery

The region which constitutes this river basin is traditionally a dry tract, which depended entirely on groundwater for all purposes. Over the years, there has been a secular lowering of water table, resulting in groundwater depletion in many parts. The introduction of modern mechanized pumping technologies has fundamentally altered the dynamics of agricultural water supply and use. This is all occurring in an area with marked seasonal variations in precipitation and relatively low levels of groundwater storage.

This region (Tiruppur town and its suburbs) has entered into the global map for its concentration of knit-wear industries. There are over 3000 knitting mills and over 800 dyeing and bleaching industries in this region. A very high concentration of dyeing and bleaching units in this region not only consumes a huge quantity of fresh groundwater but also discharges them back into the Noyyal river. The estimated quantity of water consumed by these units is about 100 million liters per day.

The Noyyal river looks pathetic with effluent flowing in it all through year. The threat posed by this dam can be illustrated by what has happened in February 1997. The Orathapalayam dam constructed across the Noyyal river was overflowing with effluent endangering quite a number of villages around.

Eventually, at the time when there was no appreciable flow in the Cauvery river, the Public Works Department opened the gates of the Orathapalayam dam to let the polluted water flow down without any prior warning to the public. The effect was devastating. Considerable damage occurred to crops, animals, soils and groundwater. Several hundred animals collapsed after drinking this water. Several petitions were filed in the Court claiming for compensation. All this went in vain.

The severity of the situation was such that Government was forced to release 20,000 cusecs of water from Mettur dam with a view to reduce the pollution load in the Cauvery even though it was a dry period.   

Waterways of Chennai

The waterways of Chennai namely the Cooum and Adyar river and the Buckingham canal were described. Once clean water ways they now carry sewage and industrial effluent. Chennai waterways cleaning moves have been a gross failure although over 1000 crores of rupees have been spent so far. There are reported to be about 750 sewage and effluent outfalls into these waterways carrying over 700 mld of waste water - untreated - finally mixing with Bay of Bengal.

The River Cooum, once a fresh water source is today a drainage course collecting surpluses of 75 small tanks of a minor basin. The length of the river is about 65 km, of which 18 km, fall within the Chennai city limits. This once fishing river and a boat racing ground has borne the brunt of the city's unplanned explosion.

The Buckingham canal which is the most polluted of the three major waterways in the city with nearly 60 per cent of the estimated 55 million litres of untreated sewage being let into it daily, including by Chennai Metropolitan Water Supply and Sewerage Board was also dealt with.

Janakarajan also discussed issues related to the Adyar river, a flood carrier of Chennai and how it is full of municipal sewage and effluent discharged by industries. Estimated industrial pollutant loadings discharged into major rivers in Tamil Nadu was also presented.

In conclusion, Janakarajan raised a number of questions. Is it impossible to sustain industrialization and urbanization development without compromising with our rivers and water resources? On the contrary to what the neo-classical economists argue, why does the market turn out to be a mute spectator – contributing to more and more environmental and ecological damages rather than cleaning up the mess? We cannot bear if the ecology back fires! Should we wait until such time? What are the ways forward? What is the role of Pollution Control Boards and laws? Is PIL a solution?

If none of these work, what is the way out? Is there a deadlock? Or is it the curse of the democracy such as the one we have in India? Or can we renegotiate our democracy? If yes, what are the ways?

Between living and dying

The presentation began with an account of what could have been a living river in the Western Ghats. Good forested catchment, habitat continuity, flowing from source to sea, carrying freshwater upto the coast, intact river banks with continuous riparian stretch constituted some of the characteristics. Others included fertile flood plains and deltas enabling agriculture to thrive, rich biodiversity, river dependent communities and livelihoods with a sense of belongingness and ownership to their river and river culture and aesthetics moulded by landscape, people and livelihoods.

Kerala’s rivers are unique in that all of them originate from the Western Ghats – ‘hotspot’ among 34 global biodiversity hotspots. The most biodiversity rich region in the entire 1600 km Western Ghats supports over 30 million population. It has short torrential monsoon fed rivers with steep gradient from east to west. These rivers have a very high fish diversity ( 260 – 312 sp ), very high endemism (109 – 129 sp) and support very high population for such small rivers. These drain into wetlands and backwaters - the Vembanad and Kole ( Ramsar sites). The well being of the rivers is inextricably linked to the well being of the Western Ghats.

The important rivers of Kerala include Periyar, Bharathapuzha,  Pamba, Chaliyar and Chalakudy. The major interventions contributing to dying rivers are catchment deforestation and habitat fragmentation in the Western Ghats, dams and diversions, sand mining, incorrect land use, pollution and encroachments into rivers.

Most rivers hover between living and dying and there is no untouched pristine river in Kerala. According to A Latha, Chalakudy is on the brink, Periyar is dying while Bharathapuzha is a dead river.

There has been a flow fragmentation in the Chalakudy basin and the direct modifiers of daily and seasonal flows (time, duration, frequency) have led to modification in the river channel and flood plain habitats. In case of Bharathapuzha the rivers have got disconnected from flood plains and the sediment flow changes have impacted downstream aquatic life.

The seventeen dams of Periyar have led to disconnected flows. The 38 km river stretch between Mullaperiyar to Idukki  dries up during summer. Below Idukki group of dams, the river dries up in the 30 km stretch. 1440 MCM of water is annually diverted to Muvattupuzha river after power generation. Nirar tributary is diverted to Tamil Nadu through Parambikulam dam’s part of PAP treaty.

According to an IWMI study, high score for sensitivity along with high scores for ecological condition indicate that ecological aspects of river are important and high environmental flows are required. The river also has a right to flow. Ecological values of rivers need to be recognized and respected by planners, policy makers and implementing agencies and integrated into the planning process. There is a need to plan for development of river basin within ecological limits and not as per hydrological potential.

Latha suggested some indicators for river health - extent of intact catchment, aquatic diversity, protected areas in the river basin, degree of flow regulation and fragmentation, extent of sand mining, human dependence (use and misuse), water quality and extent of saline ingress.

Latha suggested the following for reverting from dying to living rivers. Firstly, eco-restoration of catchments and protection of sources should be done. Secondly, there should be reservoir operations management strategies for dammed and regulated rivers for improving flows (Chalakudy river). Thirdly, there is a need for sand audit based regulation and sand mining ‘holidays’ to be declared in heavily mined stretches. Fourthly, there should be river bank protection (vegetative). Finally, decentralized water management options in place of river dependent centralized options are needed for rivers (like Mullaperiyar).

She concluded by saying that there is a need to ensure minimum and acceptable water quality. Policy changes integrating ecosystem needs and services into planning – eg. land use planning in a river basin is required. Policy support and enforcement to ensure flow regime is worked out, water is released for the ecosystem needs/ abstraction is limited to meet ecosystem needs in heavily utilized rivers – e flows implementation is required. Finally, dam decommissioning for dams like Mullaperiyar can serve as a means to improve the flows . 

Playlist: Rivers of Tamil Nadu and Kerala 

The lecture in various parts can be viewed on Youtube here:

The presentations by the speakers are attached below.

Related content

The lectures in the series can be viewed here:

India Water Portal is grateful to Prof. Ramaswamy Iyer and the India International Centre for allowing it to record the lecture and share the videos online. 

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