(Note: It is the 4^th longest river in Kerala. Chalakudy River is the one of very few rivers of Kerala, which is having relics of riparian vegetation in substantial level. The annual report of the National Bureau of Fish Genetic Resources Lucknow, mentioned that the Chalakudy River is the richest river in fish diversity perhaps in India. The riparian forests of the Chalakudy River have revealed the existence of a thick riparian vegetation of more than 10 metres width for a distance of 10.5 km downstream from Peringalkuth, covering an area of 58.5 hectares. Out of this, 26.4 hectares lie within the Vazachal area, including three large islands densely covered by riparian forests. The riparian forests of the area have been found to be characterised by the presence of typical riparian species of plants, in addition to evergreen and semi-evergreen species. Out of the 319 species of flowering plants identified from the study area, 24 are endemic species of the Western Ghats and 10 are rare and endangered. Moreover, the Chalakudy River is known for its diversity, as it contains 85 species of fresh water fishes out of the 152 species known from Kerala. Among these, 35 are endemic species of the Western Ghats and nine are considered to be endangered. The famous waterfalls, Athirappilly Falls and Vazhachal Falls, are situated on this river. For irrigation purposes Thumboormoozhy Dam is constructed across this river. It merges with the Periyar River near Puthanvelikkara, adjacent to Manjali, North Paravur in Ernakulam District. The Parambikulam Dam has been built on the Parambikulam River, one of its four tributaries.)

• Chalakudy River Map