The Police National Dive Squad will join the search for the missing swimmer at Omanawa Falls tomorrow.
Police Search and Rescue were called to the falls at 2.55pm after a report a person was "missing in the water", a police spokeswoman said.
Police were able to help two people from the water, but a third person remained unaccounted for.
Council staff are limiting access to the area overnight, before searches resume in the morning.
A police spokeswoman said police were alerted to a "report someone's missing in the water" at 2.55pm.
Police, fire and ambulance are at the entrance of Omanawa Falls Rd and a helicopter can be seen flying above the area.
Tauranga Police sergeant Ben Gallagher at the scene said an operation was under way with police, ambulance and fire.
"At the moment it is an operation for a swimmer who had gone missing," Gallagher said."
Gallagher said the friends of the missing swimmer and any witnesses were still at the bottom of the falls and were in the process of being brought back up to the top.
Nearby residents had gathered at the scene after hearing a helicopter fly above their properties and over the falls.
One resident, who did not want to be named, said everyone knew when the helicopter flew past it was bad news.
"It is a nice place but it is dangerous," he said.
He believed it was the third time this year a helicopter had been called to an incident at the falls.