They were returning home from a forest area after grazing their cattle and fell into the rivulet while crossing it and drowned late last night, a police officer said.
They have been identified as Dhyan Singh (40), his wife Leela Devi (36) and niece Aarti Devi (16).
The bodies have been recovered and were handed over to their family members, he said.
A case has been registered in this regard, he added.