Queenstown Lakes District Council property and infrastructure acting general manager Simon Mason said contractors were "responding urgently" to the overflow of partially treated wastewater, which had made its way to a "small section of natural swamp" nearby.
As a precaution, the Shotover Delta Rd has been closed, while walking tracks remain unaffected and open.
"Crews are currently onsite working to resolve the issue and determine exactly what has caused the pond to overtop," Mr Mason said this afternoon.
The council had notified Otago Regional Council’s pollution team of the overflow — its compliance officers were onsite investigating.
The spill was not linked to ongoing repairs at the treatment plant, focused on resolving problems with the facility’s aeration grids.
On that, Mr Mason said a temporary aerator was operating at the plant, spare parts from the United States had arrived and were being installed.
"As these repairs are made, the biological process treating the wastewater will progressively recover over the coming days and weeks and we hope to see the end of odour in the area soon after that," he said.
