A 52-year-old grandmother was one of 17 arrested following a series of drug busts by Rotorua police.
Police executing 10 search warrants at several Rotorua "tinnie houses" in the past week found drugs and stolen property.
Those arrested face more than 150 charges between them, including the possession and supply of methamphetamine, cannabis and cannabis oil.
Rotorua Detective Sergeant Ryan Yardley put the operation's success down to information police received from locals concerned about criminal activity in their neighbourhoods.
"This operation has demonstrated that Rotorua communities have had enough and they are taking action to do something about it. They are to be commended for coming forward," he said.
It was "particularly disappointing and disturbing" for police to find children at some of the homes involved in the drug sting, Mr Yardley said.
"Due to the activities of those around them, they have been exposed to the day to day world of drug dealing. This is not okay."
The children had been referred to Child, Youth and Family.