Queenstown Lakes Mayor Jim Boult has labelled a group of revellers who flooded into Queenstown Mall at midnight on Saturday "complete cretins".
He has vowed to look at the situation, with the council, to ensure such behaviour is not repeated.
"I just wish those people wouldn't bother coming to our town — it's absolute stupidity."
NZME photographer George Heard was in Queenstown on Saturday night when bars closed at midnight, as per Easter trading laws.
A video he took showed hundreds of people chanting in Ballarat St, one person falling from a tree in The Mall, and a man shaking a lamppost until it broke.
Boult said ratepayers would be left picking up the bill for the damage — "the last thing we need at the present time".
"We just don't countenance that behaviour and I can only hope the video reaches the police and they're able to identify the idiot concerned," he said.
Boult said he understood how the situation arose — by law, all bars must shut at midnight before Good Friday and Easter Sunday, meaning all patrons are ejected from premises at the same time.
While that was "probably not helpful", it was the law "and we've got to live with [it]".
"However, we've got to find a way to stop it happening again."
Three of the whales succumbed on the shore.