Problems
The Cooum River, or Koovam, is one of the shortest classified rivers draining into the Bay of Bengal. It is about 72 km long, flowing 32 km in Chennai and the rest in rural areas. The river is highly polluted in the urban area, where it receives untreated sewage, industrial effluents, and solid waste from various sources. The river has been termed the “most polluted” river in the country by the Central Pollution Control Board (CPCB) in a recent report. According to the report, the Biochemical Oxygen Demand (BOD) in the river between Avadi to Sathya Nagar was 345 mg per liter, the highest among the 603 rivers of the country. BOD is a measure of the amount of oxygen required by microorganisms to decompose organic matter in water. A high BOD indicates a low level of dissolved oxygen and poor water quality. The report also states that the number of polluted rivers in Tamil Nadu has increased in the past four years. The water quality of 12 rivers in Tamil Nadu was monitored at 73 locations during the period between 2019 to 2021. The BOD in 53 locations of 10 rivers did not comply with the prescribed water quality criteria. The Cooum River has been the subject of several restoration and clean-up efforts, but none have successfully improved its condition. The Chennai Rivers Restoration Trust (CRRT) was set up in 2009 to restore the ecological and hydrological functions of the Cooum River and other waterways in Chennai. The CRRT has undertaken various projects such as Interception and Diversion (I&D) systems, Sewage Treatment Plants (STPs), removal of encroachments, beautification of river banks, and creation of recreational spaces along the river.
Discharge of untreated sewage and industrial effluents into the river from various sources
One of the major problems the CRRT faces is the continuous flow of untreated sewage into the river from various sources, including stormwater drains. Around 900 sewage outfalls to the Cooum are yet to be plugged in. The Chennai Metro Water Supply and Sewerage Board (CMWSSB) has been implementing several projects as part of the Cooum River eco-restoration project. This includes 10 I&D systems along the river and three modular STPs at Chetpet, College Road, and Maduravoyal, all under various stages of completion. However, these projects have also raised concerns over their feasibility and sustainability. For instance, the CMWSSB has decided to lay sewer lines over the river bed instead of through road cuts, risking further pollution of the Cooum through possible leakages. Experts have also questioned the effectiveness of these temporary measures in relieving the river of sewage and suggested that strengthening the existing sewage system should be a priority.
Consequences of water pollution
The pollution of the Cooum River has serious implications for the environment and public health. The river is a source of drinking water for many people living along its banks, who are exposed to various water-borne diseases such as cholera, typhoid, dysentery, and hepatitis. The river also affects marine life and biodiversity in its estuary and the Bay of Bengal. The river is a habitat for many species of fish, birds, reptiles, and mammals, which are threatened by the loss of oxygen and food sources due to pollution. The river also plays a vital role in maintaining the hydrological balance and preventing flooding in Chennai during monsoon seasons. The Cooum River is a valuable natural resource that deserves to be restored and protected for its ecological, economic, and social benefits. It is not only a river but also a symbol of Chennai’s history and culture. The restoration of the Cooum River requires a holistic and integrated approach that involves multiple stakeholders such as government agencies, civil society organizations, private sector entities, academic institutions, media outlets, and local communities. It also requires a long-term vision and commitment that goes beyond short-term measures and cosmetic changes.
Gallery
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Timelines
2024
June 11
White effluents were discharged into Cooum along Poonamallee High Road. Stretching for about 72km, Cooum has historically faced pollution due to unchecked discharge of industrial effluents, domestic sewage, and solid waste. Despite numerous promises and initiatives by authorities to clean and rehabilitate the river, tangible action remains minimal, leaving the waterway in a state of environmental neglect. The risk of flooding during heavy rain is now high as the river’s ability to manage and drain excess water is compromised. The visible consequences and change in the color of the water raise an urgent need for comprehensive control and regulation to restore the river to its previous state.
March 23
In brazen violation of rules, a private tanker was seen emptying untreated sewage into the Cooum River from Mogappair bridge at 11.30 am. Metrowater built a monitoring and control center to keep tabs on licensed private sewage tankers plying in the city. “We have around 400 licensed sewage lorries in Chennai and 50-60 more are awaiting licenses to transport sewage,” said T S Arun Kumar, chairman, of TN Sewage Lorry Operators Association. “Only licensed lorries are allowed to operate and all of them have GPS trackers. The lorries are supposed to leave sewage at Metrowater-controlled decanting stations.” Metrowater is supposed to track the locations of licensed private sewage tankers via GPS but isn’t able to do that efficiently. Its monitoring center can track only one sewage lorry at a time. A tanker operator told TOI that many do not want to pay the charges to Metrowater to drop the sewage load in their decanting stations, and thus release its waterbodies.
2023
April 26
More than 25 families who were living along the banks of the Cooum River on Mayor Ramanathan Salai were evicted by the Water Resources Department (WRD), as part of the Cooum River Restoration Project. Most of these families belong to the Betta Kurumbar community, which was declared as Scheduled Tribes, who sell bamboo products.
2018
About 21,665 tonnes of waste was removed from the river.
2014
June 08
Chennai Rivers Restoration Trust (CRRT) was launched in 2014 by the Government of Tamil Nadu to restore the ecological and hydrological functions of the Cooum River and other waterways in Chennai. The CRRT has undertaken various projects such as Interception and Diversion (I&D) systems, Sewage Treatment Plants (STPs), removal of encroachments, beautification of river banks, and creation of recreational spaces along the river.
2010
October 09
The Tamil Nadu government signed an MoU with Singapore Cooperation Enterprise (SEC), a Singapore agency for the restoration project. The agency prepared a preliminary report after discussions with various stakeholders of the project including Chennai Corporation, municipal administrations, Metrowater, Pollution Control Board, Slum Clearance Board, and the public works department.
2009
June 22
M. K. Stalin, the 1st Deputy Chief Minister of Tamil Nadu launched a project to clean and revive the Cooum River in 10 years on 22 June 2009. The project was estimated to cost ₹ 1,200 crores and involved various activities such as desilting, removing encroachments, constructing sewage treatment plants, and beautifying river banks. However, the project faced many delays and challenges due to a lack of coordination among various agencies, public apathy, inadequate funding, and technical issues.
2006
October 15
The Government of Tamil Nadu has formed a trust namely Adyar Poonga Trust (APT) to develop an Eco park in 58 acres of Adyar Creek. The trust was later renamed Chennai Rivers Restoration Trust (CRRT) in 2014.
2001
January 11
Chennai City River Conservation Project (CCRCP) was launched by the Government of Tamil Nadu with the support of the Union Environment and Forests Ministry. The project aimed to improve the water quality and ecological status of the Cooum River and other waterways in Chennai by arresting the sewage outfalls and strengthening the sewer network. The project was estimated to cost ₹ 12,000 million and involved various activities such as the construction of sewage treatment plants, interceptor drains, check dams and stormwater drains along the river.