Palwinder Singh went to a branch of Upper Bari Doab Canal (UBDC) for taking bath and is feared drowned, they said.
His body was yet to be recovered, they said.
Singh was serving in the Indo-Tibetan Border Police (ITBP) and was posted at Assam.
He had come to his village Nikko Sarain under Dera Baba Nanak police station on leave, they added.