A person brought what was thought to be explosives to the police station.
Filming of a Hollywood movie is continuing around the Whanganui region.
"It appears to be a systems failure - commonly called a cock-up," the landowner says.
"All water in the rohe is culturally and historically connected to each other."
A Whanganui company was part of the group behind the power reconfiguration.
Drones have been used in various emergencies from search and rescue to large fires.
A large group of protesters gathered at Pūnakewhitu/Gentle Annie on Thursday.
The winner of the Rangitīkei Southern Ward byelection has been announced.