A Fox Rd resident said the parties had only started being a problem about a year ago, and now they were being thrown every two to three weeks.
She described feeling "panicked" as yelling and screaming teenagers and young adults spread down the street.
"People are absolutely terrified," she said. "Every two weeks it's the same blimmin thing."
The morning after the parties, the streets and lawns would be littered with cans and smashed bottles, she said.
"Sometimes there's a hundred kids or more ... they even stop cars from coming through the street."
Other neighbours had had "a gutsful" of the parties, she said.
"No one really knows how bad this is and how often it's gone on. It doesn't stop."
Another neighbour agreed that the parties were happening every few weeks, and said they were starting to become more of a problem, while another woman said Saturday night's party was particularly loud.
"That's what woke me up, screaming," she said.
"I didn't want to turn a light on. I'm not frightened, I just don't like it.
"I feel sad that they're of that age and they're doing that sort of thing."
She said most of the partygoers looked to be about secondary school age.
"It is a problem."
Another man living on the street didn't think the parties were any more a problem on Fox Rd than they were elsewhere in Wanganui.
He said they happened every couple of months.
"This is about the third or fourth bad one we've had ... I don't know whether it's a problem. I think you get it everywhere."
He didn't think they had a particular problem with bottles and cans being thrown on to the street and into properties.
"We get the odd one chucked on the lawn, but that happens all over Wanganui."
Mr McDonald said it was "hugely resource draining" for police to be attending out-of-control parties.
"It's never a pleasant thing, dealing with a large crowd of people who are intoxicated [and having to] evict people from a party," he said.
"We have a lot of well organised, well controlled parties in the city that we're aware of every weekend that we have no issues with."
It was common for people to throw parties with 100-200 guests which didn't get out of control if they were pre-planned and had "a bit of forethought".
"We've got to take our hats off to those," he said.