Chennai’s Adyar river shows signs of recovery after years of government investment

The long suffering residents of Chennai have been living with two dead rivers, the Adyar and the Cooum, flowing through the heart of their city. These two rivers meander sluggishly through the city carrying sewage and dangerous pollutants. Besides these two rivers, there is the third one – the Kosasthalaiyar, which flows in the northern end of the city and not as polluted as the other two. These three rivers flow east towards the Bay of Bengal.

A river is considered dead when it is incapable of sustaining any form of life – fish or aquatic plants, in it. This happens when the pollution level in the river is so high that all the oxygen in the water is depleted.

The fresh water flowing through the Adyar and Cooum rivers are blocked upstream of the city and diverted to storage reservoirs for the city. The rivers also have sand bars blocking their mouth into the sea, thereby obstructing even the tidal flushing action from the sea.

The Tamil Nadu Government has been working for a long time to restore the three rivers and several other water bodies in Chennai. Large sums of money have been allotted for this purpose but the progress has been slow. In the recent years, the government created a trust to coordinate a more concerted effort in cleaning the water bodies in the city.

A trust for restoring the rivers and waterways

The Chennai River Restoration Trust (CRRT) coordinates the work between various government departments, such as the Public Works Department (PWD), the Greater Chennai Corporation (GCC), the Chennai Metropolitan Water Supply and Sewerage Board (Chennai Metro Water), Tamil Nadu Slum Clearance Board (TNSCB) and some NGOs who are involved in this project. To facilitate the activities of the trust, a special purpose vehicle (SPV) under the Companies Act, called Adyar Poonga, was formed.

In 2019, the government allocated Rs 23.70 billion and Rs 13.70 billion this year for restoring and cleaning water bodies in Tamil Nadu. The government expressed its concern over the amount of raw sewage flowing through the river and allocated this amount mainly to clean the drains which empty into the river. However, the enormity of the problem is often difficult to comprehend.

Over the past three decades, the Adyar has been used as a dumping site not only for building debris but for municipal as well as industrial waste. During the massive Chennai floods of 2015 the river was flushed clean. But once the flood waters subsided it got polluted again.

A river, estuary and creek

The Adyar starts its 42 km journey at Adhanur and winds its way through Thiruneermalai, Tambaram, Manapakkam, Alandur, Saidapet and finally empties itself out into the Bay of Bengal between San Thome beach in the north and Elliots beach in Chennai city.

What makes the Adyar riverine ecosystem unique is that there is an estuary and a creek. The Adyar estuary region stretches from Thiru Vi Ka Bridge to the river mouth and the creek from the San Thome Causeway to the river mouth spread over 358 acres. The Adyar creek is a backwater estuary at the mouth of the river formed by a sandbar at the mouth of the river and runs along the coast. It starts near the Chettinad Palace and stretches north; surrounding Quibble Island.

Early on, the authorities realised that cleaning efforts by well-intentioned citizens would be of no use as the problem was too deep and a scientific approach was needed.  In 2006, the Tamil Nadu Government took cognisance of the problem and set up the Adyar Poonga Trust to protect and restore the three rivers, the Buckingham Canal and other water bodies in the city. The trust was later renamed as the Chennai River Restoration Trust (CRRT).

Moving people

One of the first issues which had to be undertaken in restoring the river was rehousing human settlements along the banks, according to an official source who wished to remain anonymous. A CRRT official added that 47 human settlement areas were identified along the Adayar River banks. Of the settlements that have been identified and located, 10 of them were beyond the project area and another 10 settlements were not affected by the project.

So, one of the first tasks undertaken by the CRRT along with the Tamil Nadu Slum Clearance Board (TNSCB) was the resettlement and rehabilitation of the people living along the river banks.

Of the 47 slums identified, 27 were within the project area from where families were to be resettled. There were 9539 project affected families who were part of the resettlement and rehabilitation plan and have been shifted to tenements newly constructed by the TNSCB.

The irony of Adyar is that it is not just the poor and marginalised who live and play by the river. Once the river passes under the Kotturpuram Bridge the landscape of the river changes and those living on its banks are the rich and affluent.

On the banks of the Adyar is one of the oldest boat clubs in India – the Madras Boat Club. This river is one of the few in the country that is used for rowing. National and international competitions are held on these sluggish waters.

Revi Thomas, a veteran rower, says, “Thirty years ago when we rowed out from Madras Boat Club to the Broken Bridge the water was clear and the surrounding wetlands were conducive to bird life. We could see large flocks of birds near the river. Sadly, now we see nothing.”

Plugging sewage outfalls

Krishna Mohan Ramachandran, chief resilience officer, Chennai city (the Chennai chapter of 100 Resilient Cities programme, supported by the Rockefeller Foundation), said the pollution in the river increases once it enters Chennai near Porur.

According to media reports, the fiscal outlay of Rs. 23.70 billion in the state budget was primarily targeted at plugging and mitigating sewage flow into the Adyar, Cooum and the Buckingham Canals.

An official source said that 67 sewage outfalls into the Adyar river were identified. To plug these outfalls, it was necessary to lay interception and diversion pipelines and this task is being undertaken by the Chennai Metro Water. The project will reach completion in 2022, according to CRRT.

The CRRT is also planning to set up four modular sewage treatment plants (STPs). According to the tender document, the contract of the STPs was awarded in February this year at a cost of Rs 126.2 million.

Ramachandran added that one of the other steps taken by the CRRT was to demarcate the land which ‘belonged’ to the river ; which in some areas was 30 metres along the river banks and in others 50 metres. To this purpose the GCC began fencing the river in 2018. This fence is also a deterrent to dumping garbage into the river.

It is estimated that the GCC will spend Rs 22 crore to complete fencing along the river from Thiru Vi Ka bridge to Meenambakkam. The foundation and pillars are made of concrete with treated iron grills in between which will allow the flood waters to flow in between.

Adyar creek

According to an official at the CRRT, the initial restoration activities were undertaken in 58 acres of the Adyar Creek. The creek was used as a place for disposal of municipal solid waste, construction debris and sewage, which led to the severe degradation of surface and groundwater quality and destruction of habitats of avian fauna, reptiles and fishes. The creek was infested with Prosopis juliflora bushes, mosquitoes and bad odour which kept local people away.

The official said that in order to rehabilitate the coastal ecosystem of Adyar Creek, a slew of restoration works have started in the degraded areas. Desilting and removal of accumulated solid waste were taken up and the same were used to create mounds within the creek to enable plantation, reduce noise pollution and bring tranquillity to the restored wetland system. Sewage outfalls into the creek were identified and plugged.

A total of 143,818 saplings from 173 species of Coromandel coastal vegetation including mangroves and mangrove associated plants were systematically planted in order to restore the wetland ecosystem.

A glimmer of hope, finally

Today, there is some hope in sight as the restoration work undertaken bears fruit. These measures resulted in a substantial increase in the water spread of the creek from 5% to 59%, the CRRT official said. Planting of indigenous species resulted in a sizable increase in biodiversity of the creek due to the creation of habitat islands and edges with coastal vegetation which serve as a habitat for terrestrial animals and nesting birds.

The work done on the restoration has yielded some results. According to a policy note tabled in Tamil Nadu Assembly for the year 2019-20, the faunal diversity of the Adyar Creek has gone up.  The report said as many 8 species of molluscs, 13 crabs, 170 insects, 12 fishes, 10 amphibians, 19 reptiles, 120 birds and 16 mammals have been recorded. In the estuary 57,000 mangrove and 35,000 terrestrial saplings have been planted after the removal of invasive species, debris and plastic waste.

The CRRT official said that besides being a 58-acre lung space within the heart of Chennai city, the Adyar Ecopark today functions as a hub for imparting environmental education to the community at large, and students in particular.

But it has not been smooth sailing. The Principal Bench of the National Green Tribunal considered imposing a fine of Rs. 10 million towards damages “for the repeated failure of the State in its duties in preventing pollution in the Adyar River, the Cooum River and the Buckingham Canal.”

But, a senior official of the Tamil Nadu government said that this is not an easy project. It is complex, as it involves so many governmental departments, so many entities and finally, so many people. Hence it would take time – maybe four or five years even to finally restore the river.

Governmental spending to restore the Adyar had begun in 1990s, and projects were initiated over multiple time periods. Though there is a glimmer of hope in the recent years, there is more to be achieved before the city dwellers can start seeing the river as a usable water body rather than a drain.

Read more: Looking beyond the Chennai city, at the Chennai watershed

Banner image: The broken bridge on the Adyar river. Photo by special arrangement.