Deputy inspector general (headquarters) Amit Sinha told HT the police received information about his drowning at around 3:30pm.
Four members of a family were killed and as many were swept away in landslides and cloudbursts triggered by heavy showers.
The State Disaster Management and Mitigation Centre here said more than 12 houses were damaged.
Vinod Thapa, a labourer; his wife, Sarita; and their two children were killed in their sleep in a slum area in Dehradun when early morning rain caused a landslide in a nearby hill and boulders fell on their shanty, made of wood and asbestos, the police said.
Though the locals had started rescue operations, the family could not be saved. The slum, an illegal settlement, has a population of around 1,000.
Four persons were reportedly swept away in a cloudburst in the Kapkot division of Bageshwar district after four houses collapsed. Three persons were rescued from beneath the rubble. A combing operation is on.
On Tuesday night, nine houses were damaged in a landslide in Almora district.
Debris caused by landslides has piled up on roads, disrupting traffic.