Adyar River

The Adyar River, which originates from the Adhanur Lake in the Kanchipuram district, is one of the three rivers that winds through Chennai, Tamil Nadu, India, and joins the Bay of Bengal at the Adyar estuary. The 42.5-kilometre (26.4 mi) long river contributes to the estuarine ecosystem of Chennai. Despite the high pollution levels, boating and fishing take place in this river. The river collects surplus water from about 200 tanks and lakes, small streams and the rainwater drains in the city, with a combined catchment area of 860 square kilometres (331 mi2). Most of the waste from the city is drained into this river and the Cooum.

The Adyar starts from the Malaipattu tank (80.00° longitude and 12.93° latitude) near Manimangalam in Sriperumbudur taluk at about 15 kilometres (9 mi) west of Tambaram in south Chennai. It begins to resemble a stream only from the point where water released from Chembarambakkam Lake joins the river at Thiruneermalai. It flows through Kancheepuram, Tiruvallur and Chennai districts for about 42.5 kilometres (26.4 mi) before joining the Bay of Bengal in Adyar, Chennai. Here it forms an estuary, which extends from Adyar Bridge to the sandbar at the edge of the sea, with some small islets in between. The estuary attracts a wide variety of birds. The estuary covering an area of about 120 hectares (300 acres) was made a protected wildlife reserve in 1987. The river forms a backwater near the mouth, known as the Adyar creek, due to the formation of sand bar at the mouth. This creek is a natural channel which carries tidal water back into the sea. The river has varying depth of approximately 0.75 metres (2.5 ft) in its upper reaches and 0.5 metres (1.6 ft) in its lower reaches. The catchment area of the river is 530 square kilometres (200 mi2). Bed width ranges from 10.5 to 200 metres (34 to 656 ft). It flows for 24 kilometres (15 mi) in the Chennai Metropolitan Area including about 15 kilometres (9 mi) within the Chennai district before draining into the sea. It discharges about 190 to 940 million cubic metres (150, 000 to 760, 000 acre⋅ft) water annually to the Bay of Bengal. The discharge is seasonal with about 7 to

Flows through: India.

River data from Wikidata (CC0); lengths normalised to a common unit.