The downpour fell on already sodden ground, leaving landslides, flooded roads and trapped residents in its wake.
But Environment Canterbury councillor Vicky Southworth said the sting felt by locals from this week's flooding is only a hint of what's to come.
"We're going be dealing with more frequent and more intense rainfall, the science is very clear on that. There are various solutions, and they're not being particularly pushed."
She's well versed in those solutions, having undergone a master's degree investigating stormwater management on personal property in Christchurch.
Options to minimise flood risk in homes range from permeable pavements, to rain gardens, which redirect rain collected on roofs to gardens instead of stormwater drains.
"Even just simply putting more trees into our gardens. Trees are a fantastic way of catching rain before it hits the ground," she said.
Southworth said while these small-scale fixes help water stay out of homes, they must go alongside bigger investment into infrastructure.
Christchurch City Council head of Three Waters and Waste Helen Beaumont said the council has spent a significant amount on the issue, with flood retention basins across the city able to hold 1.7 million cubic metres.
She said the basins at the upper catchment of the Heathcote River made a monumental difference to some suburbs.
"I think we would've had significant flooding of houses if we hadn't had those basins yesterday. Of course, there was still a lot of water, but it didn't climb the steps and into the front rooms, so we're pleased about that."
But as weather becomes more extreme, flood mitigation costs will continue to increase.
Environment Canterbury is one of a number of regional councils who've asked the government for an annual $150 million fund towards nationwide flood protection, and councillor Ian Mackenzie said it was a no-brainer.
"Of all the things under climate change that the government can spend money on, one of the most effective and cost-efficient things is actually flood protection," he said.
Beckenham resident Diane, who lives across from the Heathcote River, hopes more funding will be directed to the issue.
She's resigned to regular floods on her street, but this winter's been tough.
"From time to time the river's spilled over, but not very often. But we've had three spill overs in three weeks."
And with such relentless rain, she thinks Southworth's solutions aren't such a bad idea.
"I think having responsibility over my property is important to me. I probably would be happy to contribute to towards making my own property safe."
But Beaumont said the city's wetland origins means residents have to accept that some areas won't keep up with worsening weather, as it's mapped out in council flood zone plans - a tough pill to swallow for those who've called Ōtautahi home for decades.
