Boy racers have damaged the newly sealed plateau car park on the mountain.
Chief executive Sven Hanne the carpark had been resealed, in a report updating Councillors.
He said the project had been fully funded by NZTA and was completed earlier this year.
Councillor Jono Erwood asked if the seal was still in good condition.
"Can you confirm the state of it? I understand at the last snow dump that was up there that damage had been done to the car park."
Roading manager Steve Bowden said Councillor Erwood was correct about the damage to the car park, however the cause wasn't just poor weather.
"I was up there a month or so ago. As part of the upgrade we created a couple footpaths around the perimeter with rocks to try and slow down the amount of rain that runs off the carpark.
"Since we completed the seal, the hoons had a bit of a field day so it is not in that good a condition anymore.
"If we were to reseal the car park we would be looking at $60,000-70,000. It was sealed with chip seal."
Deputy mayor Jamieson asked who would cover the cost of any future resealing.
"As it is a road of natural significance will there be no cost to Council if it gets redone?"
Steve said despite NZTA funding the original sealing, Council would have to pay for any resealing costs.
Ongoing maintenance of the carpark is fully funded by NZTA.
Speaking after the meeting, Sven said irresponsible use of the carpark was a historic issue, so they need to consider whether to take the risk to reseal it.
"The carpark is not dangerous to use, but we are disappointed by the damage caused."