Many shoppers descending on Moorhouse Avenue supermarkets in droves insisted they weren't panic buying, just picking up a few essentials for themselves and others.
At Countdown and New World, limited entry meant queues outside the door, and at Pak'nSave, the carpark was quickly completely full.
Inside the supermarkets, shoppers described scenes of bickering and groceries tumbling from shelves.
Ronnie, a self-confessed panic buyer, said his priority was getting bottled water so he wouldn't have to drink chlorinated Christchurch tapwater for four weeks.
He said he had trouble staying calm after hearing about the imminent lockdown, and didn't support it.
"I'm starting to wonder now if the government should just shut up and let it play its way through. This is crazy... this is spreading panic," he said.
But Libby Gawith, a tutor at Ara Institute, said she supported moves to act early, to be "like Taiwan and Singapore and keep out stats low".
"It'll be fine. New Zealand will be fine. We're locked off and we're catching all our cases," she said.
She had gone there to do some shopping on behalf.
"I've got a student who hasn't eaten for three days. She isn't getting StudyLink for another day or two so I'm taking emergency groceries to her because she's hungry," she said.
Another shopper, Kendra Wadsworth, says she would have avoided the supermarket if it weren't for the medical supplies she needed.
"I'll be going back home soon to my parents so they've sorted out all the food and everything... so not a panic buy for me, no," she said.
Gawith said she wasn't expecting quite such large crowds, but she was under no illusions the situation would get better quickly.
"We know from people in France and Spain and all the rest of it, that this is what we'll do every day. Queue for food. The new normal," she said.
Supermarkets are asking people to be kind to their staff, and to help make sure there's enough product on the shelves for the elderly, when friends and relatives are shopping for them.
The police commissioner is warning shoppers that officers will intervene if there's any disorder.
