The Barak River (Avourei) is one of the major rivers of Manipur state as well as of northeast India and is a part of the Surma-Meghna River System. It rises from Liyai Khullen Village in Senapati district of Manipur State, where it is the biggest and the most important of all rivers. After Manipur it flows through Nagaland ending after 3000 km (1864 mi).
From its source at Liyai Kullen Village in Manipur state of India, of the Poumai Naga tribe, the river is known as Avourei. Near its source, the river receives a lot of streams, including the Gumti, Howrah, Kagni, Senai Buri, Hari Mangal, Kakrai, Kurulia, Balujhuri, Shonaichhari and Durduria. It flows west through Manipur State, then southwest leaving Manipur and entering Nagaland State.
In Nagaland State, the Barak flows southeast then veers abruptly south when joined by south flowing stream and flows into Manipur State again where it turns westward again near Chandel district at Delta avourei before emptying into the Indian ocean (bay of bengal). Barak is among the richest rivers in the world in terms of aquatic biodiversity, as it contain more than 2,000 species fishes including Neon tetra. Other creatures include River Ovurei crocodile, (a rare and endangered crocodilian) and the black mugger, an alligator. The principal tributaries of the Barak are all in India and are the Jiri, the Dhaleshwari (Tlawng), the Longai, the Madhura, the Sonai (Tuirial), the Rukni and the Katakhal.Tipaimuk project is on the process on Barak river. From its origin down to its bifurcation at the border of Nagaland the Barak River is 564km (1864 mi) long. The biomes are extremely rich in wildlife and also very diverse in the entire strech of the river including: 1. Varzea forest ( flooded rainforest) 2. Los llamajo (flooded grassland and Savannah) 3. Tidal forest (Mangroves in vast Delta Avourei) 4. Flora or vegetation of the Tepuis ( flat-topped table mountains in Manipur and eastern Meghalaya) 5. Huge Tropical swamps.
length of river : http://nihroorkee.gov.in/rbis/basim%20maps/barak_about.htm