Bluff’s wastewater looks set for a shake-up as an expiring consent looms for the existing system.

On Thursday, Invercargill City Council held a workshop to discuss the future of the town’s discharge network which currently pipes into Foveaux Strait through a 50-metre outflow pipe.

The meeting revealed a preference from the project's working group for the discharge to take a new route through a wetland en route to the marine outfall.

Council group manager infrastructure Erin Moogan said it had been a “few tough weeks” for the working group as it worked through options at pace on the back of an August 6 committee meeting.

“But the team had put their heads down, worked through some tough and challenging conversations and came to a point where they agreed unanimously on a preferred option to recommend to the governance group for the project.”

The objective was to have safe and reliable discharge that was achievable, affordable and deliverable, she said.

“It is a huge, hefty project for the community and for council, and people have put an awful lot of time into it."

Outcomes would also need to reflect partnership with local rūnanga and Te Ao Marama — which represents Ngāi Tahu in resource management and local government.

The proposed overland method through the wetland would be more expensive than the current arrangement, but is a preferable option for cultural reasons.

Present at Thursday’s meeting was Te Runaka o Awarua chairman Dean Whaanga, who said his team had a relationship with the piece of coastline where the wastewater plant sat.

“Having an appropriate, cost-effective wastewater treatment plant is really important to iwi,” Whaanga said.

The proposed “surface flow wetland” model would still make use of the Bluff Wastewater Treatment Plant, which was built in 2000.

Any final decision would have to be discussed at committee level and then full council.

Endorsement was also required from local rūnanga and the Bluff Community Board ahead of the next committee meeting on October 8.

To date, the working group process has taken nearly one year and cost more than $750,000.

The existing wastewater consent expires in December 2025.

LDR is local body journalism co-funded by RNZ and NZ On Air