Manjalar originates from Palani Hills, Tamil Nadu and runs towards east and joins the Vaigai River near Koottathu. There are nine anicuts and nine tanks in this sub-basin. It receives an annual rainfall of 775 millimetres (30.5 in). The total sub-basin area is 470 square kilometres (180 sq mi). The total ayacut of the sub-basin is 2,155.53 hectares (5,326.4 acres).^[1]

The Manjalar Dam spans the river near Batlagundu.