The tail end of a storm which ravaged much of the lower North Island hit Dunedin on Monday and the persistent rain was upgraded to an orange heavy rain warning at noon yesterday.
Sandbags were available as a precautionary measure in South Dunedin and Mosgiel, while barriers diverting wastewater to mudtanks were trialled in Surrey St.
Surrey Street Flood Action Group convener Lynne Newell told the Otago Daily Times sewage was spilling over manhole covers into the street at 9am yesterday and her toilet was not working.
"This is a psychological problem that everyone in Surrey St and the two streets around us faces any time it rains — is it going to flood us again?" she said.
In a social media post earlier this month, the Dunedin City Council disagreed with Ms Newell’s comments there were no natural hazards in South Dunedin and flooding was caused by infrastructure issues.
"The issue is the capacity of the network during periods of heavy rainfall, exacerbated by high groundwater levels which leave nowhere else for rainwater to go," the post continued.
This was "BS", Ms Newell said yesterday.
She did note the council was reacting to wastewater overflows faster, but "the pipes are not fine".
The council did not directly respond when asked if it stood by its social media comments.
City services general manager Scott MacLean said the council was satisfied the network performed well, helped by precautionary measures.
Minor and localised wet weather overflows were reported — it was not aware of any affected private property, he said.
The council has previously said a permanent solution to wastewater overflows is tied to the Green Island wastewater treatment plant upgrade, funded late in the council’s nine-year plan.
Speaking in the afternoon, when the worst of the rain appeared to have past, Ms Newell said a sewage pumping van had been sent to her property to address the overflow issues.
"They’re obviously trying to avoid any problems. So they’re doing what they can with as much equipment as they can to safeguard people’s property — I will say that.
"But ... every time it happens, thousands and thousands of dollars are spent on remediation rather than proactively fixing things properly," she said.
Taskforce Green placed sandbags in front of her and neighbouring properties, although one property reported sewage flooding in the backyard from a manhole cover in another street, Ms Newell said.
"It’s definitely not the worst result we’ve had ever, by any means."
Mr MacLean said maximising pumping through the Portobello pumping station and activating an overflow at the Tahuna wastewater treatment plant, while releasing partially treated and heavily diluted flows into the ocean, also reduced pressure on the wastewater network.
"Opening the outfall at Lawyers Head will affect water quality ... people are advised not to swim in the ocean, or collect shellfish, for the next 24 hours."
