The Bharathapuzha River originates from the Annamalai Hills in the Western Ghats region of Tamil Nadu. The Bharathapuzha River is the second longest river in Kerala at 209 km. It is also known as Nila, Kuttipuram Pooja and Ponnaniyar. The major tributaries of Bharathapuzha are the Gayatripuzha, Kannadipuzha, Kalpathipuzha and Thuthapuzha rivers. The Palakkad Gap, along with many tributaries, including the Tirur River, flows westwards through the districts of Palakkad, Thrissur and Malappuram in Kerala.