Cooum River
The Cooum River, or simply Koovam, is one of the shortest classified rivers draining into the Bay of Bengal. This river is about in length, flowing in the city of Chennai and the rest in rural part. The river is highly polluted in the urban area. Along with the Adyar River running parallel to the south and the Kosasthalaiyar River, the river trifurcates the city of Chennai and separates Northern Chennai from Central Chennai. It is also sometimes known as Thiruvallikenni river
Its source is in a place by the Kesavaram Anaicut built across Kallar river in Vellore district adjoining Chennai district. From its origin in the Kesavaram village to Thandurai, Avadi, Thiruverkadu Anaikat, the river remains unpolluted. Beyond this point, the river is highly polluted till its mouth on the Bay of Bengal. In Chennai district, the river flows through three corporation zones—Kilpauk, Nungambakkam and Triplicane—for a total length of.
Owing to the intensive use of surface water upstream for agriculture, indiscriminate pumping of groundwater leading to reduced base flow in the river, formation of a sand bar at the mouth of the river, discharge of untreated sewage and industrial effluents, and encroachment along the banks, the river, especially downstream, has been highly polluted. In 2018 alone, about 21,665 tonnes of waste were removed from the river.
History
The Cooum was earlier known as the Triplicane river. The name of Cooum appears to be derived from Tamil literature. The name may have been derived from the Tamil term coopam meaning 'well' or 'deep pit'. The word coovalan denotes a person who is well versed in the science of ground water, well water and stagnant water.Once this river was said to have its origin in Dharmapuri district, but now due to some earth table changes, it has shortened its course to Thiruvallur district. Ancient documents from the nearby temples states about one 'reaching salvation' on having a dip in the Cooum. The Cooum river was then clean and unpolluted.
For centuries, Cooum has been an integral part of the socio-economic and cultural life of the city. Till the early twentieth century, it was a clean river, most suitable for navigation. In ancient times, it played a pivotal part in the far-flung maritime trade between the Roman Empire, South India and Sri Lanka. Cooum's proximity to the ancient port of Manarpha or Mylapore added to the river's strategic importance. Manarpha was frequented by Roman merchants who came here to buy Indian textiles, gemstones and spices. In return, India procured gold, silver, copper and high-quality wine from the Romans. Archaeologists have discovered ancient Roman wine jars, and Roman and Chinese coins, on the banks of the river. In the late eighteenth century, Pachaiyappa Mudaliar, a philanthropist, bathed in this river before offering prayers at the Komaleeswarar Temple in Komaleeswaranpet.
Cooum River and the nearby Elambore River, which flows into the Cooum at its mouth, were running very close to each other near the former Central Jail area opposite Chennai Central. During floods, both the watercourses inundated the whole area. In the 1700s, the two rivers were linked by a cut to equalise the floods in both the rivers and a bridge was constructed between these rivers in 1710 across the cut.
Polluted part of the Cooum is presently spoiled by filth and pollution, and the water quality has considered to be highly toxic and completely non-potable. The 2004 tsunami cleaned the mouth of the river; however, the river returned to its usual polluted self within a short period. Nevertheless, the river is still being used for drinking water needs of many villages in the banks of the unpolluted part of the river.
Origin and course
The Cooum River originates in a village of the same name in Kadambathur union in Tiruvallur district, about from Chennai, although starting its main course at Sattarai village, around from Chennai. Flowing through Thiruverkadu, it enters the Chennai District at Arumbakkam after meandering for about. It then passes through some of the oldest residential areas for another such as Choolaimedu, Chetpet, Egmore and Chintadripet, where the river channel is about wide. Close to Egmore, the river forks into two—the northern and the southern arms—both of which join again near the Napier bridge, thus forming an island, known as the Island Grounds. The northern part of the Buckingham Canal joins the Cooum near the old Central Jail while the southern part of the same canal emerges from the river, just behind the University of Madras campus. The river finally joins the Bay of Bengal south of the Fort St George, just below the Napier Bridge. Once a fresh water source, it is today a drainage course inside the city of Chennai. The total length of the river is about. The river flows to a length of in the Chennai Metropolitan Area, of which fall within the Chennai district limits. The total catchment area of the river is about, and the bed width ranges from. The capacity of the river is, and the anticipated flood discharge is around. Once a fishing river, it has borne the brunt of the city's unplanned developmental explosion. The Kesavaram dam diverts the river into the Chembarambakkam Lake from which water is used for the supply of drinking water to the city of Chennai. Thereafter, the flow of water in the river is much reduced.Three ancient Shiva temples are located at the source of the river. The first is Tiruvirkolam, in Cooum village, and the other is at Ilambaiyankottur. The third is Thiruverkadu Shiva temple. Koyambedu temple is also in its banks. These temples have been featured in the Thevaram sung by the Saivite saint Thirugnana Sambandar. There is one more temple called the Veerebathrasami temple. The god in the temple is otherwise known as "Akoramoorthy". This temple is at Pillayarkuppam, from Cooum village. In ancient Tamil Nadu, under the Chola Empire, the river Cooum was referred to as Kashtabudhyotpathihi. They all form a group of villages called Padhinaru Nattham. The river drains into the Bay of Bengal at Chepauk in Chennai marking the northernmost boundary of the Marina Beach. The delta also marks the southern boundary of the Port of Chennai.
The width of the river course varies all along from, which includes the area occupied by the slums.
Islets and the river mouth
The major islet in the course of the river is the Island Grounds in Chennai less than a kilometre from the mouth. The river splits into two near Chinthadripet and encircles a piece of land isolating it from the surrounding land before draining into the eastern sea. However, the mouth of the river is not too wide and does not have any islet. The river mouth has groynes running to a total length of nearly. The opening between the groynes is about to facilitate tidal action. The impact of high tide bringing in sea water is felt for nearly in the river. At present, the river has to be periodically cleaned to prevent sand deposits near the river mouth, close to the Napier bridge, which are removed at frequent intervals using at least two machines to facilitate tidal action and avoid flooding. About of sand were removed in 2010–11.The river basin spans an area of 505.88 square kilometers.
Bridges
There are nine major bridges built over the urban part of the river. These are the Napier Bridge, the Wallajah Bridge, the Periamet Bridge, the Chintradripet Bridge or the St Andrew's Bridge, Harris Bridge, Commander-in-Chief Road Bridge, College Road Bridge, Spur Tank Bridge and the Aminjikarai Bridge. Apart from these there are several smaller bridges built across the river. The Corporation of Chennai maintains about 13 of these bridges.A new bridge across the river connecting Golden George Nagar in Mogappair with Nerkundram is being constructed by the state highways department at a cost of 113 million. Work started in August 2010 and is expected to be completed by March 2013. The bridge with 10 spans measures about long and nearly wide, accommodating six-lane traffic, with space provisions for bicycles and pedestrians.
Flora and fauna
According to scientists, around 1950, Cooum had 49 species of fish, and by the late 1970s, this was reduced to 21 species. However, on date, there are no fish in the river, owing to highly toxic pollutants found in the river water.Pollution
The river is narrow, placid, slow and meandering. The river is primarily fed by discharge from tank and water bodies and has seen a steady drop in freshwater over the years, a primary reason for its present-day condition. However, the core problem of the Cooum has been that due to the sand bar, the river mouth near the Napier Bridge gets blocked for most of the time, preventing the river water from draining into the sea. This has, eventually, made the river, in its 18-km-long stretch in the central district, a stinking cesspool.Tests of water samples reveals almost zero dissolved oxygen and substantial presence of faecal coliform bacteria, besides heavy metals such as lead, zinc and cadmium.
The study of the river was undertaken as part of a World Bank-funded project and shows that it is 80 per cent more polluted than treated sewer. Fish were able to survive in the water for only 3 to 5 hours even after samples were diluted. There are traces of heavy metals like copper and pesticides like endosulphan and lindane in it. Public Works Department sources said government agencies like Chennai Corporation and business units and retail outlets on the banks of the river were responsible for the pollution. The water has almost no dissolved oxygen, and instead there are traces of heavy metals like copper, besides sewage and sludge. Due to its narrowness and about 3,500 illegal hutments along its banks, it has not been recently desilted, which has closed it to river traffic. Per 2003 enumeration, about 9,000 families live along the river, in addition to 450 shops and commercial buildings. There are 700-odd points in the river bank where sewage flows straight into the river. There are 127 identified sewage outfalls into the river, out of which 85 are in use.
Nearly 30 per cent of the estimated of untreated sewage being let into the waterways of Chennai daily, including by Chennai Metropolitan Water Supply and Sewerage Board, gets into the Cooum river. About 60 per cent of the untreated sewage gets into the Buckingham Canal and the Adyar River takes the rest. In 2010, about 340 sewage outfalls into the waterways were identified. Of them, more than 130 sewage outfalls were in the Cooum River and a majority of them were between Aminjikarai and Nungambakkam. In some of the spots in areas such as Maduravoyal, more than 7 tonnes of municipal solid waste is being dumped in the river every day.
Fortunately, there is another 42 km of this river which is still not polluted, which can be used to transport the water into Chennai and to store drinking water for Chennai's needs. There is a huge amount of sand deposits in the banks of the unpolluted part of the Cooum river that could rejuvenate the ground water level of numerous villages in the banks of this river.