Whanganui's mayor Annette Main says the city's reputation has taken a hit because of foul odours from its wastewater plant.
The bad smells have been causing distress to residents in pockets of the city since December.
But the district council said stopgap measures - including installing new aerators and applying lime by helicopter - were working.
The measures have cost more than $1 million.
Ms Main said the smell has had an impact on the city's reputation.
"It isn't visitors so much that would be aware of it as the rest of New Zealand through comments that people have been making.
"And it is unfortunate that that is damaging our reputation because it is still and always will be a fantastic place to live."