Jules Radich was told by the Otago Regional Council (ORC) it was likely resource consent would be needed to rebuild the St Clair groyne because "the groynes no longer exist".
But Mr Radich was yesterday adamant the groyne was an existing structure and the council could go ahead with the cheaper option of applying for a certificate of compliance for a trial.
"The [ORC] were under the misconception that there is no remaining structure.
"There’s plenty of poles still there ... there’s far more of the structure available for us to repair than what might be imagined," he said.
ORC consents manager Joanna Gilroy yesterday reiterated what the regional council had said to the mayor in previous advice.
"There is no structure to replace or reconstruct," Ms Gilroy said.
Whether the groynes are an existing structure is set to have a significant bearing on the cost of the project, as indicated by the Dunedin City Council estimating consenting costs for the project could range between $15,000 and $250,000.
Mr Radich said using the 1919 plan of the groynes — a design drawing depicting a single row of piles — was another reason the project should get a certificate of compliance.
"To me, the answer is really straightforward. It’s a pre-existing object, and it’s been there since 1919, and we have the original plan.
"Therefore, it deserves a certificate of compliance."
Mr Radich had not passed on the ORC’s advice to the other Dunedin city councillors, but discussed the matter with planners involved with the coastal plan.
"I didn’t provide it to other councillors. I had a conversation in my own right."
Last week, city councillors voted 9-5 to seek a certificate of compliance which would enable them to go ahead with a trial reinstatement of the St Clair groynes.
It was hoped a timber groyne might help build up the beach.
A confidential staff report, now partly released to the Otago Daily Times, said operating costs could be up to $110,000 a year.
Construction costs were consistently estimated at $320,000.
Mr Radich said he did not know if there was a point where the project would be considered too expensive to pursue.
"When you look at the sand sausages which have had millions-plus spent on them ... where would you draw the line with too expensive?"
