From its origin in the Kesavaram village to Thandurai (Pattabiram), Avadi, Thiruverkadu Anaikat, the river remains unpolluted.

In ancient times, it played a pivotal part in the far-flung maritime trade between the Roman Empire, South India and Sri Lanka.

In the late eighteenth century, Pachaiyappa Mudaliar, a philanthropist, bathed in this river before offering prayers at the Komaleeswarar Temple in Komaleeswaranpet.

It then passes through some of the oldest residential areas for another 18 kilometres (11 mi) such as Choolaimedu, Chetpet, Egmore and Chintadripet, where the river channel is about 30 metres (98 ft) wide.

The river finally joins the Bay of Bengal south of the Fort St George, just below the Napier Bridge.

The total catchment area of the river is about 400 square kilometres (150 sq mi), and the bed width ranges from 40 to 120 metres (130 to 390 ft).

The river drains into the Bay of Bengal at Chepauk in Chennai marking the northernmost boundary of the Marina Beach.

[10] 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.

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.

[12] 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.

[9] 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.

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.

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.

[14] 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.

[13] In 1996, when the DMK returned to power, the government made another bid—this time covering all important watercourses, including the Buckingham Canal and the Adyar.

This resulted in the implementation of the ₹ 12,000-million Chennai City River Conservation Project (CCRCP) in January 2001, which was substantially supported by the Union Environment and Forests Ministry.

However, this too did not yield the desired results since the project did not cover Tiruvallur district, which accounts for 54 kilometres (34 mi) of the river stretch.

The upper region of the river, mainly Kancheepuram, Chengalpattu and Thiruvallur districts, will be benefiting from this special fund.

The team comprised former Deputy Chief Minister M. K. Stalin, former Chennai Mayor M. Subramaniam and other senior officers.

The initiative has been taken up by the Central and State governments to clean up the river and rediscover the pleasures of traditional boat racing.

[19] In September 2011, the WRD began cleaning the river at a cost of ₹ 10.2 million and the work is expected to be completed within a fortnight.

[14] In 2012, the government allotted ₹ 3,000 million towards construction of 337 sewage cleaning systems in the waterways in the city, including 105 locations in the Cooum river.

[21] In 2011, the Tamil Nadu Sailing Association planned to build a marina at the mouth of the Cooum river along the southern bank, where yachts and pleasure boats could dock.

The ₹ 300-million project involves first building a breakwater in the sea so that the waters at the marina are placid and the boats do not keep bobbing up and down with the incursion of waves.

However, the by-catch is a more important function—the breakwater will prevent silting and clogging of the river's mouth, allowing for structures such as a boat repair facility, a base for the Tamil Nadu Coastal Police, and sailing academy to be put up on the bank.

[23] A nature trail along the river has been proposed for which a draft ecological plan has been prepared by the Tamil Nadu Urban Infrastructure and Financial Services Limited (TNUIFSL).

According to the draft ecological plan, floral species such as Indian almond, black wattle, sacred fig, madras thorn, Indian mulberry, neem, banyan, magizham, Indian cork tree, punnai, sirukkambil, karumugai, shenbagam, bayur tree, kadamba, pavazha malli, vetiver grass, palmarosa, agave, lemon grass and subabul would be part of species along the nature trail which would play a role in erosion management.

Five points located at 200-metre (660 ft) intervals along the trail have been selected for erecting break-out areas including one for a canopy walk.

Modelled on the San Antonio River Walk in the United States, the trail is being built in two phases at a cost of ₹ 98.2 million and includes a butterfly park in a 5000 square meter area.

A 1928 poem by V. H. Shipley describes the river as follows:Of dirt and smell your sources wake... And near the sea where one would think Your water might be cleaner, It forms a cesspit by the bridge, Adjoining the Marina.