A section of Surrey St between Hillside Rd and South Rd was covered in excrement that flowed out of a manhole.
Surrey Street Flood Action Group convener Lynne Newell said elderly residents in the street were having to "pee in a bowl and poo into a bag" because their toilets were out of action from about 1am on Saturday.
The city council has said it took proactive measures ahead of the weather but Ms Newell said the situation got worse as the day proceeded and the rain continued to pour down.
Residents were unable to use their toilets because the sewerage system in the street was overloaded with sewage coming from the hill suburbs, she said.
"I was lucky that I've got a [non-return] valve so it doesn't come up and spew over my toilet bowl, but the thing is I still have to use a bucket to pee in and a bag to poo in — it's like a Third World country."
She said sewage water overflowed into properties and on to the street every time there was significant rainfall.
"The roads might not flood but the sewerage can’t cope with what’s happening."
The council had been telling her a solution was around the corner for the past 20 years, she said.
"I have bashed my head against a brick wall for ten months and nothing is getting promised or fixed."
The ODT saw human waste and menstrual products in the water on Saturday.
Ms Newell said her wastewater services began working again late Saturday night.
Speaking on Saturday, Dunedin Mayor Jules Radich said the residents’ bathrooms would be usable again as soon as the rain eased.
He said it was incorrect to say nothing had been done to address the issue as non-return valves were installed to make sure residents’ bathrooms were not back-filled with wastewater.
A pipe that went through Caversham tunnel needed to be removed and its removal was funded and included in the nine-year plan.
Council chief executive Sandy Graham said overall, the network coped well with the weekend’s rain.
There were some areas of "isolated ponding" and some manholes surging "slightly" but the council received no reports of wastewater discharging into properties, she said.
"Due to pressure on the network some toilets may have been unable to be flushed for a short period overnight, however they should still have been usable.
"During the rain event the mayor and staff were in regular contact with Ms Newell and we will follow up with her again to hear her suggestions for improvement.
"We took a proactive response to the rain event by providing sandbags, draining the network, ensuring contractors and staff were checking the network and responding promptly to any issues and communicating regularly."
Ms Graham said $44.2m had been set aside in the nine-year plan capital budget for further flood alleviation work in South Dunedin, which included "no regrets" improvements to be implemented quickly.
On Saturday, the council climate and city growth manager Scott MacLean said teams responded to isolated incidents and inspected the network for damage and flooding.
Temporary road closures were put in place and, with the exception of the Logan Park artificial turfs, all council grounds were closed to the public.
Coastal Dunedin bore the brunt of the weekend rain — about 25-50mm, with other parts of Otago getting 20-50mm, the Otago Regional Council said in a statement early on Saturday afternoon.
"Flood infrastructure is doing its job and performing as expected.
"There were no significant issues overnight."
