But the Waitaki District Council is unsure yet if it will even carry on with the project.
The council held its public activity update last week, giving councillors the opportunity to grill staff on specific projects.
Cr Jim Hopkins queried the cost of the pond-clearing project which was planned within the next three months.
Council infrastructure manager Joshua Rendell said he did not have the figure.
But staff were trying to work out how to do the work within the approved budget "and still get the same outcome".
Mr Rendell said the preferred methodology of digging out the sludge had been identified and was expected to improve the pond’s water quality.
However, part of the budget was also to identify a suitable place to dispose of the sediment.
Council projects leader Erik van der Spek confirmed the budget was $300,000.
Council recreation manager Lindsay Hyde said "a volume of material" had been identified under the project for disposal but the viability of it hinged on redistributing the pond dredgings elsewhere within the public gardens.
Further investigation of this would give staff the ability to say whether "it will be viable for this project to move ahead".
"If the numbers don’t stack up, we will look at retiring the project," Mr Hyde said.
Meanwhile, erosion of the true left bank of Oamaru Creek beside the Top 10 Holiday Park, requiring urgent work, had been noted.
