The Dunedin City Council could divert wastewater away from a low-lying suburb into a nearby stream in a bid to prevent flooding.
File photo of flooding in South Dunedin Photo: RNZ
Untreated sewage flowed in South Dunedin during flooding earlier this year as the wastewater system exceeded its capacity.
It was not the first time wastewater has contaminated the area during heavy rain, and the council is concerned it won't be the last time unless the issue is resolved.
The council is planning to redirect wastewater to a different treatment plant.
However, that is a major project expected to take more than eight years to complete.
Instead the council has mooted the temporary diversion that could see a large amount of wastewater diverted away from South Dunedin into Kaikorai Stream during heavy rain.
Three Waters group manager Tom Dyer said the plan isn't intended to be a "permanent or ideal solution".
The wastewater overflows would be heavily diluted and screening would be in place to prevent solid matter entering the stream, Mr Dyer said.
"Clearly, discharging a large amount of wastewater, albeit heavily diluted and screened, into a stream, will have an impact on the environment.
"However, we believe that the benefits to human health and wellbeing far outweigh the environmental impacts in this situation, until the permanent solution has been constructed."
The council would need to apply for a resource consent for the plan to go ahead and it would only be used when absolutely required to help protect human health, he said.
Currently, the wastewater flooding in South Dunedin is eventually discharged into Otago Harbour during heavy rain.