Vamanapuram River is an 88-km long river in southern Kerala

Kerala

or Keralam is an Indian state located on the Malabar coast of south-west India. It was created on 1 November 1956 by the States Reorganisation Act by combining various Malayalam speaking regions....

. The river originates in the Chemunjimotta hills (alt. 1860m) hills on the southern side of the Western Ghats

Western Ghats

The Western Ghats, Western Ghauts or the Sahyādri is a mountain range along the western side of India. It runs north to south along the western edge of the Deccan Plateau, and separates the plateau from a narrow coastal plain along the Arabian Sea. The Western Ghats block rainfall to the Deccan...

, and flows through Thiruvananthapuram

Thiruvananthapuram district

Thiruvananthapuram District is the southernmost district of the Indian state of Kerala. It came into existence in the year 1957. The headquarters is the city of Thiruvananthapuram which is also the capital city of Kerala....

 and Kollam

Kollam district

-Climate:Kollam's temperature is almost steady throughout the year. The average temperature ranges from 25 to 32 degrees Celsius. Summer usually runs from March until May; the monsoon begins by June and ends by September. Kollam receives an annual average rainfall of around...

 districts of Kerala.It ends in AnjengoLake(Anchuthengu Lake) near Varkala

Varkala

Varkala is a coastal town and municipality in Thiruvananthapuram district situated in the Indian state of Kerala. It is located 50 kilometres north-west of Thiruvananthapuram and 37 km south-west of Kollam city.Varkala is the only place in southern Kerala where cliffs are found adjacent to...

.
The two tributaries of this river are the Upper Chittar & Manjaprayar streams.