He said the sculpture could need regular cleaning and being at such a height that would be no easy task.
"Also it has the potential for birds to nest in it, that would make it an eyesore," he said.
To a suggestion a cherry picker could be used for cleaning and maintenance Mr O'Donoghue said that would not help.
"It would allow a maximum height of six metres.
"The sculpture is to be 18 metres high -- the bottom of it is five metres off the ground -- so you would need to use certified scaffolding."
He said it was on the cards scaffold hire and cleaning could cost up to $20,000.
The cleaning concerns have been rejected by the Aratoi Foundation with chairman Bob Francis telling councillors the sculpture would be made of aluminium and to a high standard of construction.
It would be coated with "two or three coats of special paint for protection".
Mr Francis said vandalism concerns could also be dismissed due to the height of the structure.
"You would need a stepladder just to touch the bottom, vandalism will not be an issue," he said.
Maintenance, insurance and power costs have been estimated at between $8000 and $12,000 a year and would become council's responsibility.
Finance manager David Paris said an engineer had been commissioned to investigate any potential problems from wind and had concluded the sculpture would withstand "any extreme winds we get here".
Once it has ownership the council is likely to agree not to depreciate the sculpture and when it came to the end of its life would expect any replacement to be community-funded.
Masterton mayor Lyn Patterson said in view of some of the issues raised by councillors she suggested standing down the sculpture issue until a full council meeting on March 23 for receiving further information and this was agreed to.