Locals passing nearby noticed a foul smell and a body in the drain. They informed the police following which a team reached the site and pulled the body out, they said.
More villagers reached the site but could not identify her as the body was highly decomposed and was apparently lying in the drain for over a week, they said.
The body has been sent for post-mortem.
People of nearby villages have also been asked to provide information in order to obtain the identity of the deceased, police said.