Manimala River

Manimala River is a 92km long river which flows through South and Central Kerala. The river used to be wrongly considered as a tributary of Pamba River before satellite maps became popular, but this is was proved incorrect. Manimala does not flow into the Pamba, instead a distributary of the Pamba river flows into the Manimala river at Kallunkal, later branches out at again from Manimala at Nedumpuram and flows through Niranam, Thalavady, Edathua, Changankary, Champakulam, Nedumudy, Chennamkary, and finally Kainakary and then empties into the Vembanad lake. This branch again links with Manimala river at Chennankary in a short, but broad connection known as Munnattumukham. Manimala is a separate independent river for all geographical purposes. It has its origin on the Muthavara Hills (1156 feet above main sea level) on the Western Ghats in Idukki district of Kerala, India. It has a length of about 90 km and flows through a catchment area of about 847 km2. The river passes through the districts of Kottayam, Pathanamthitta and Alappuzha . Yendayar, Koottickal, Mundakayam, Erumeli, Manimala, Kottangal, Kulathurmoozy, Vaipur, Mallappally, Keezhvaipur, Thuruthicad, Komalam/Kuranjoor Kadavu, Kallooppara, Vallamkulam, Kattode & Kuttoor (outskirts of Thiruvalla city), Pulikeezh, Nedumpuram, Neerattupuram, Amichakary, Muttar, Kidangara, Pulincunnoo, Veliyanadu, Ramankary, Mankompu lie on the banks of Manimala River. Manimala splits after Kidangara into two branches. Second branch flows via Kunnamkary, Kavalam and Kainakary to Vembanad lake. Its running length is estimated at 92 km. It empties itself into the Vembanad Lake. It is one of the four major rivers which do not have direct outlet to sea as these rivers (Meenachil, Pamba, Manimala, Achankovil) empty into the vast Vembanad lake. This huge lake has just two outlets, one at Thottappaly Spillway and second at Thannermukkom Bund, both man made barriers, built to prevent incoming seawater during high tides, which otherwise would render the low lying paddyfields (average 2.5 meters below sea level) uncultivable.
Niranam is historically known as an ancient inland port at the confluence of Manimala River and Pamba River. At Kaviyoor ancient rock-cut cave temples can still be seen.
Manimala River has been an important water way of Central Travancore. Rising in the hills of Kottayam-Idukki ranges, running westward, the river joins the plains at Manimala junction and then the flows through the midland plains and through the Kuttanad rice bowl area. Sand mining on the river bed has led to depletion of the water ways of the river. Pollution is also another issue.
References.
Ichthyodiversity of Manimala River