A west - flowing river, Chalakudi River originates from the Anamalai Hills in Tamil Nadu
. This 144 km long river passes through Thrissur
districts before merging with the Periyar River
at Puthanvelikkara village in Ernakulam District
. The main tributaries of the river are Parambikulam, Kuriyarkutti, Sholayar, Karapara and Anakayam.
The scintillating Athirappilly Waterfalls and Vazhachal Waterfalls are part of the Chalakudi river stream.
Sholayar Dam, 65 km east of the Chalakudi town, and Peringalkuttu Hydro-Electric project are built across this river. Besides, the Chalakudi River has a healthy population of fish including Deccan Mahaseer.