Pamba, the third longest river in Kerala is formed by several streams originating from Peerumedu plateau in Idukki district, enters Alappuzha district at Chengannur and flows through Pandanad, Veeyapuram, Thakazhy, and Champakulam through a distance about 177.08 Km and plunges into vembanad lake through several branches such as Pallathuruthi Ar, Nedumudi Ar and Muttar. The river has a length of 117 Km and is navigable to a length of 73 Km.. The catchment area of this river is 1987.17 Sq.Km. The main tributaries of the river are Pambayar, Kakki Ar, Arudai Ar, Kakkad Ar and Kallar.