"Evidence gained from a party goer established that there was a high potential for missiles to be thrown with the backyard covered in empty glass bottles," police said today.
The previous week police had also closed the address down and also had "a large amount of glass thrown" at them.
"This gave us good cause to wear our full protective equipment which worked very well. No staff received injuries. I am confident that no complaints about police actions will be received."
Every window in the back-section Frankleigh Street flat has been smashed.
Graffiti covers every wall, including the one-car garage.
Broken glass litters the front pavement, driveway, and around the house, along with hundreds of squashed beer and mixer cans.
One neighbour said she had phoned police earlier in the night as the party escalated.
"It was turning ugly pretty early on,'' said the woman, who did not wish to be named.
"They were all pretty young and just going crazy, screaming, shouting, loud music, smashing bottles.
"And they just kept coming. There were hundreds of them. I knew it was going to get out of control.
"I just wished the cops would've turned up sooner than they did.
"It was quite unnerving, wondering what was going to happen. Terrifying actually.''
The Christchurch party chaos marred an otherwise calm New Year's Eve around the country.
Police said revellers in the main centres of Auckland, Wellington and Dunedin were reasonably well-behaved and there were no major incidents.
Bay of Plenty saw the New Year in "peacefully'' with just a minority of people preventing the celebrations from being completely trouble-free, while Waikato Police reported celebrations in Whangamata were "friendly and "trouble-free''.
